Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District Board Regular Meeting of the Capitol Region Watershed District (CRWD) Board of Managers, for Wednesday, May 21, 2014 6:00 p.m. at the office of the CRWD, 1410 Energy Park Drive, Suite 4, St. Paul, Minnesota. REGULAR MEETING AGENDA I. Call to Order of Regular Meeting (President Joe Collins) A) Attendance B) Review, Amendments and Approval of the Agenda II. Public Comment – For Items not on the Agenda (Please observe a limit of three minutes per person.) III. Permit Applications and Program Updates (Permit Process: 1) Staff Review/Recommendation, 2) Applicant Response, 3) Public Comment, and 4) Board Discussion and Action.) A) Permit # 13-027 Vintage on Selby (Kelley) B) Permit # 14-012 Lower Villa Park Improvements (Kelley) C) Permit # 14-013 Goodwill (Kelley) D) Permit Program/Rules Update (Kelley) IV. Special Reports – 2013 Stormwater Monitoring Report, Britta Suppes V. Action Items A) AR: Approve Minutes of the May 7, 2014 Board Meeting (Sylvander) B) AR: Approve April Accounts Payable & Budget Update (Sylvander) C) AR: Highland Ravine Stabilization Project (Eleria) a. Award Bid b. Approve Contract Amendment for Engineering Services D) AR: Adopt Citizen Advisory Committee Framework (Doneux) E) AR: Amend Stewardship Grant Funding Policy (Castro) F) AR: Authorize Full-Time, Temporary Water Resource Technician Position (Doneux) VI. Unfinished Business a. Lake McCarron’s Aquatic Plant Harvesting Project Update (Doneux) b. Curtiss Pond Improvement Project (Fossum) VII. General Information A) District Office Facility Update (Doneux) B) Administrator’s Report VIII. Next Meeting(s) A) Wednesday, June 4, 2014 CAC Meeting Review IX. Adjournment W:\04 Board of Managers\Agendas\2014\May 21, 2014 Agenda Regular Mtg.docx Materials Enclosed
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Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District
Board Regular Meeting of the Capitol Region Watershed District (CRWD) Board of Managers, for
Wednesday, May 21, 2014 6:00 p.m. at the office of the CRWD, 1410 Energy Park Drive, Suite 4, St. Paul,
Minnesota.
REGULAR MEETING AGENDA
I. Call to Order of Regular Meeting (President Joe Collins)
A) Attendance
B) Review, Amendments and Approval of the Agenda
II. Public Comment – For Items not on the Agenda (Please observe a limit of three minutes per person.)
III. Permit Applications and Program Updates (Permit Process: 1) Staff Review/Recommendation, 2) Applicant Response, 3) Public Comment, and 4)
Board Discussion and Action.)
A) Permit # 13-027 Vintage on Selby (Kelley)
B) Permit # 14-012 Lower Villa Park Improvements (Kelley)
C) Permit # 14-013 Goodwill (Kelley)
D) Permit Program/Rules Update (Kelley)
IV. Special Reports – 2013 Stormwater Monitoring Report, Britta Suppes
V. Action Items
A) AR: Approve Minutes of the May 7, 2014 Board Meeting (Sylvander)
B) AR: Approve April Accounts Payable & Budget Update (Sylvander)
C) AR: Highland Ravine Stabilization Project (Eleria)
a. Award Bid
b. Approve Contract Amendment for Engineering Services
Capitol Region Watershed District 1410 Energy Park Drive, Suite 4 Saint Paul, MN 55108 (651)-644-8888 www.capitolregionwd.org May 2014
TABLE OF CONTENTS
Acronyms ........................................................................................................................................ i Definitions ..................................................................................................................................... iii List of Figures ................................................................................................................................ v List of Tables ............................................................................................................................... vii
* Date/Time indicates period of operation for continuously monitored sites in 2013
2013 CRWD Stormwater Monitoring Report 13
3.2.2 FULL WATER QUALITY STATIONS
Full water quality stations in 2013 consisted of an area-velocity sensor and an automated water sampler.
The area-velocity sensors were secured to the base and center of the pipe or channel and were connected
to the automated water sampler housed above ground. Area-velocity sensors measured and recorded
water depth and velocity every 10 or 15 minutes. This data was used to calculate discharge or
volumetric flow of water at the site by relating water depth in the pipe or channel to area (each pipe or
channel has a unique relationship) and multiplying by the velocity reading.
When the flow of water reached a specified depth or velocity, the sampler engaged to collect water
samples. Generally, samplers were programmed to capture storm events greater than or equal to the 0.5
inch precipitation event. Two different sampler sizes were used: a compact sampler and a full-size
sampler. A compact sampler can collect up to 48-200 milliliter (mL) samples (2 per bottle). A full-size
sampler can collect 96- 200 mL samples (4 per bottle). A sample was collected after a specified volume
of water passed through the site in order to collect samples over the entire hydrograph. These individual
samples were combined and mixed to produce a single composite sample. This approach provides a
better representation of stormwater quality throughout the entirety of a storm or base flow event as
opposed to taking a single grab sample. To create a composite sample of an event at a given site, the
individual sample bottles were first shaken until the sampled water became homogenous. The sample
bottles were then poured together into a 14-Liter (L) churn sample splitter and thoroughly mixed to
create a homogenous sample. Once mixed, 4 liters of the homogenous sample were distributed to a
sample bottle provided by the Metropolitan Council Environmental Services (MCES) Laboratory.
Water quality samples were collected during storm events at the ten full water quality sites. With the
exception of Sarita, Como 7, and Como Golf Course Pond, monitoring sites had continuous baseflow
during dry weather periods. Composite samples of this dry weather baseflow were taken at these sites
twice a month from April to November and once a month from December to March.
Bacteria grab samples for Escherichia coli (E. coli) were taken at all full water quality sites during storm
events when runoff was generated. At sites with baseflow, bacteria base grab samples were collected
twice a month during dry weather from March to November and monthly during the winter. When
collected, bacteria grab samples for E. coli were sampled directly into sterilized containers during storm
events and baseflow periods and delivered immediately to the lab for analyses due to the short sample
holding time (6 hours).
Water quality samples were delivered to the Metropolitan Council Environmental Services (MCES)
Laboratory for analysis. The chemical parameters, method of analysis, and holding times are listed in
Table 3-4. If the lab analysis occurred after the holding time of a given chemical parameter had expired,
that chemical parameter was not analyzed.
2013 CRWD Stormwater Monitoring Report 14
Table 3-4: Analysis method, reporting limits, and holding times for water chemistry parameters analyzed by Metropolitan Council Environmental Services (MCES).
3.2.3 FLOW-ONLY AND LEVEL LOGGER STATIONS
The flow-only stations positioned at the outlets of Como Lake and Lake McCarrons use two different
methods to collect and determine discharge data. At the Como Lake outlet, flow is regulated by a
wooden weir in a manhole. A level sensor was placed on the upstream side of the weir. When the level
recorded exceeded the distance between the sensor and the weir, the structure was discharging. The
volume was then calculated based on the dimensions of the weir, the recorded level, and the periods of
recorded outflow. At the Lake McCarrons outlet, an area-velocity sensor connected to a data logger
collected and recorded water depth and velocity every ten minutes. This data was used to calculate
discharge at the site with the known pipe dimensions.
Level logger stations were operated at four storm ponds within the Trout Brook subwatershed (Figure
3-1). The data collected at these sites is used to track pond elevation in relation to precipitation. The
data is also used to calibrate the hydrologic and hydraulic model for the Trout Brook Storm Sewer
Interceptor. A pressure transducer was secured at a known depth in the pond and connected to a data
Parameter Abbreviation Method Reporting Limit Holding Time
Cadmium Cd MET-ICPMSV_5 0.0002 mg/L 180 days
Carbonaceous BOD, 5 day CBOD BOD5_5 0.2 mg/L 48 hours
Chloride Cl CHLORIDE_AA_3 0.5 mg/L 28 days
Chromium Cr MET-ICPMSV_5 0.00008 mg/L 180 days
Copper Cu MET-ICPMSV_5 0.0003 mg/L 180 days
Escherichia Coli E. coli Colilert and Colilert-18 with Quanti-Tray/2000 method N/A 6 hours
Fluoride Fl ANIONS_IC_3 0.02 mg/L 28 days
Hardness Hardness HARD-TITR_3 N/A 28 days
Lead Pb MET-ICPMSV_5 0.0001 mg/L 180 days
Nickel Ni MET-ICPMSV_5 0.0003 mg/L 180 days
Nitrate as N NO3 N-N_AA_4 0.01 mg/L 28 days
Nitrite as N NO2 N-N_AA_4 0.003 mg/L 28 days
Nitrogen, Ammonia NH3 NH3_AA_3 0.005 mg/L 28 days
Nitrogen, Kjeldahl, Total TKN NUT_AA_3 0.03 mg/L 28 days
Orthophosphate as P Ortho-P ORTHO_P_1 0.005 mg/L 48 hours
pH at 25 Degrees C pH pH by electrochemical pH probe N/A N/A
Phosphorus, Dissolved Dissolved P P-AV 0.02 mg/L 28 days
Phosphorus, Total TP NUT_AA_3 0.02 mg/L 28 days
Potassium K MET-ICPMSV_5 .03 mg/L 180 days
Sulfate SO4 SO4-IC 0.15 mg/L 28 days
Surfactants MBAS$ SM 5540 C 0.10 mg/L 48 hours
Total Dissolved Solids TDS TDS180_1 5 mg/L 7 days
Total Suspended Solids TSS TSSVSS_3 N/A 7 days
Volatile Suspended Soilds VSS TSSVSS_3 N/A 7 days
Zinc Zn MET-ICPMSV_5 0.0008 mg/L 180 days
2013 CRWD Stormwater Monitoring Report 15
logger which continuously recorded stage every ten minutes. The logger locations were surveyed
relative to a known benchmark in order to convert stage data to a true elevation.
3.2.4 PRECIPITATION STATIONS
Precipitation was measured using automatic and manual rain gauges (Figure 3-1). The Trout Brook-East
Branch and Saint Paul Fire Station No. 1 precipitation monitoring sites used automatic tipping bucket
rain gauges which record precipitation amounts continuously during storm events in order to determine
rainfall intensity. Manual rain gauges were used at the CRWD office and Villa Park. The manual rain
gauge at the CRWD office was checked and emptied each workday at 7:30 AM. The manual rain gauge
at Villa Park was checked and emptied after every storm event.
Precipitation data, recorded every 15 minutes at the UMN St. Paul campus, was used to determine daily,
monthly, and annual rainfall amounts for the Capitol Region watershed. Precipitation data from the
NWS at the Minneapolis-St. Paul International Airport was substituted for any gaps in the UMN data. It
is acknowledged that a low level of variability exists spatially and temporally for precipitation events
within the District. However, previous watershed model calibration within the District has shown that
the precipitation amount at the UMN site adequately represents that data in the District.
3.2.5 MONITORING DATA QUALITY ASSURANCE
Full water quality sites that were installed for the entire year in 2013 collected data for an average of 359
days. CRWD achieved an average monitoring efficiency of 98% at the continuously monitored full
water quality sites in 2013, meaning that 98% of all potential data was collected during the calendar year
(Appendix C). Missing data accounted for the remaining 2% and was due to equipment failure, power
failure, flooding, or vandalism. Monitoring at Villa Park, Sarita, and Como 7 was 100% efficient during
the periods they were installed from April to November 2013. The level and flow-only sites were also
100% efficient, except for the Westminster-Mississippi level logger which lost five days, making it 97%
efficient.
After the 2013 monitoring season was complete, flow data was quality checked and corrected by
removing points with missing data or negative values and interpolating their values between good data
points. If there were extended periods of missing or bad data in which there were no storm events, an
average baseflow level and velocity were calculated and substituted. For storm events where velocity
did not log accurately, but level was still logged, a stage-velocity regression equation was developed
using level and velocity data from good periods of stormflow record. The equation for the regression
line was then used to determine velocity for those periods of missing data. If this was not possible or
there were storm events during this time, the data was left as missing and not factored into discharge
calculations.
The 2013 water quality sample data reported by the MCES lab was also rigorously checked for quality.
The reported sample times and dates were compared with field notes as well as the lab chain of custody
forms. Any abnormally high or low sample values were denoted and cross-checked with field notes to
ensure the parameter value was commensurate with the conditions of the day in which the sample was
taken. Sample concentration results that were outside of the average range of data were identified as
outliers and removed from monthly and yearly average concentration calculations.
2013 CRWD Stormwater Monitoring Report 16
3.2.6 TOTAL DISCHARGE AND POLLUTANT LOAD CALCULATIONS
For all full water quality monitoring sites, the stage, velocity, and water quality data collected were used
to calculate total discharge and pollutant loads for total phosphorus (TP), and total suspended solids
(TSS). Discharge and pollutant loads were calculated for each base, storm, snowmelt, and illicit
discharge event at all sites, as well as total discharge and loads for the entire monitoring season. At the
sites monitored continuously, the totals represent annual discharges and loads. At Como 7, Sarita, and
Villa Park, monitoring equipment cannot be operated during the winter months because equipment
failure or damage can occur from freezing temperatures and ice. The 2013 reported discharge and loads
for these sites is only representative of April through November.
Total discharge and pollutant loads for the Como 7 Subwatershed include combined data from the Como
7 monitoring site and the outlet for the Como Golf Course Pond. The outflow from the pond discharges
into a storm sewer just downstream of the Como 7 monitoring site. Analysis of the combined Como 7
and Como Golf Course Pond site data was done in the same manner as all other full water quality
monitoring sites.
For Villa Park, total discharge and pollutant loads also include any discharge flowing through the
emergency overflow near the outlet of the wetland system. Discharge was quantified by placing a level
logger near the weir outlet structure that recorded the duration of an overflow period.
Flow Partitioning and Discharge Calculation
The 2013 final flow data for each site was separated into base, storm, snowmelt, and illicit discharge
intervals. For sites without sustained baseflow, all events corresponding to a precipitation event were
considered storm intervals. For sites with year-round baseflow, careful separation of stormflow and
baseflow was necessary. An event was considered a storm interval if its peak discharge exceeded a
certain threshold (unique to each site). The beginning and end of the interval were determined by
interpreting when flow first rose above baseflow conditions and when flow returned to baseflow
conditions following the storm.
In 2013, snowmelt intervals were determined differently from 2009-2012. From 2009 to 2012, snowmelt
intervals were inconsistently identified. For the 2013 data, possible snowmelt intervals were first
identified by peaks in the hydrograph exceeding 150% of the normal baseflow for the time of year.
These peaks were cross-referenced with snowpack data from the National Weather Service (NWS). A
peak was determined to be a snowmelt interval if a snowpack depth was recorded by the NWS the day
of the peak and no precipitation was recorded. If precipitation occurred on the same day as a peak and a
snowpack depth was recorded, the event was also classified as snowmelt. If precipitation (including
snow) occurred on the same day as a peak, but no snowpack was recorded, the event was classified as a
storm event.
An event was considered a potential illicit discharge if elevated flow was observed in the discharge data
that did not correspond to precipitation, snowmelt, or any other known event.
The total discharge for each interval was calculated using Isco Flowlink® (Version 5.1) software.
Flowlink was used to integrate the flow rate data in the specified interval calculating the total discharge
volume for the event. Interval discharge volumes were summed to calculate a total discharge for the
2013 CRWD Stormwater Monitoring Report 17
2013 monitoring period. Discharge subtotals were also calculated by flow type for the monitoring
period.
Interval Load Calculation
The TP and TSS concentrations, reported by the MCES lab, were used to calculate TP and TSS loads for
the interval corresponding to each sampled event. For those event intervals in which samples were not
collected, an average historical monthly concentration was applied. The average concentration is
calculated using the average of all samples collected for a given monitoring site by month and event
type (i.e. base, storm, snowmelt, or illicit discharge) for the entire monitoring record. The average
concentration values used for the 2013 load calculations are listed in Appendix E. Prior to 2013, an
annual average concentration for each event type was calculated for each year and applied to unsampled
intervals.
TP and TSS loads were calculated for each interval using the following equation:
( ) ( ) ( ) (
) (
)
Interval discharge and TP and TSS loads were summed to produce total discharge and pollutant loads
for the entire monitoring period.
3.2.7 FLOW WEIGHTED AVERAGE (FWA) CONCENTRATION CALCULATIONS
A total flow weighted average (FWA) concentration, as well as a FWA concentration for each flow type,
was calculated for TP and TSS for the entire monitoring period in 2013. The total FWA concentration
takes into account the differences generally observed between flow types. Flow weighted concentrations
take the discrete sample concentrations and weight them based on the flow volumes associated with that
event. This presents a more accurate representation than an average of all interval concentrations. At
sites with baseflow for example, pollutant concentrations tend to be higher during storm events, but
generally account for less of the total annual discharge. An overall average would be skewed toward the
higher storm concentrations. In the same manner, FWA concentrations by flow type (e.g. storm, base,
snowmelt, illicit discharge) account for differences in the relative effect of individual intervals (flow
events) on the average.
Total FWAs for TP and TSS for the entire monitoring season were calculated using the following
equation:
( ) ( ) (
)
( ) (
)
FWA concentrations for TP and TSS for each flow type were calculated by dividing the total load
associated with a given flow type by the total discharge associated with the flow type:
2013 CRWD Stormwater Monitoring Report 18
( ) ( ) (
)
( ) (
)
3.2.8 POLLUTANT YIELD AND NORMALIZED POLLUTANT YIELD CALCULATIONS
To make useful and valid comparisons of stormwater monitoring data between 2013 full water quality
data and previous monitoring years and between sites, the data was normalized to eliminate the
influence of subwatershed size and annual precipitation.
Annual yields for total discharge and total TP and TSS loads for each full water quality monitoring site
were calculated. This allows for site-by-site comparisons of the monitoring data by removing the
influence of drainage area. Water yields were calculated using the following equation:
( ) ( )
( )
Pollutant yields for TP and TSS were calculated using the following equation:
( ) ( )
( )
The total TP and TSS load data was also normalized to account for temporal and spatial differences in
precipitation. By removing the influence of year-to-year variation in precipitation, trends of pollutant
loads are more easily recognizable. Normalized pollutant yields were calculated in two steps. First,
total runoff (in inches) was calculated for each full water quality monitoring site. The amount of runoff
was calculated using the following equation:
( ) ( ) (
) (
)
Next, the normalized TP and TSS yield was calculated. Normalized TP and TSS yields were calculated
using the following equation:
(
)
( )
( ) ( )⁄
3.2.9 CUMULATIVE YIELD
Cumulative yield plots for discharge, TP, TSS, total nitrogen (TN), and chloride (Cl-) were developed
for each site. Cumulative yield plots are useful for showing the rate and temporal distribution of yield
accumulation throughout the course of the monitoring season. Each point along the curve represents the
accumulated yield from the beginning of the period up to that point in time. Separate curves were
created for baseflow, stormflow and combined flow (stormflow+baseflow) for 2013 as well as the mean
of the historical monitoring record (2005-2012). The mean cumulative yield curves were determined by
taking the average of all previous years’ cumulative yields on a daily basis.
2013 CRWD Stormwater Monitoring Report 19
3.2.10 METAL EXCEEDANCES
The toxicity of a metal is a function of water hardness. For CRWD watersheds, the chronic toxicity
standard is used, as defined in Minnesota Rules 7050.0222 for each of the 6 metals (Cr, Cd, Cu, Pb, Ni,
and Zn). Equations for the chronic standard for each metal in g/L are listed in Appendix B. Average
2013 metal concentrations from storm flow, baseflow, snowmelt, illicit discharge, and total flow were
compared to the chronic standard (table XX in results section).
A toxicity exceedance was defined as a sample concentration that exceeded the chronic toxicity
standard. Exceedances were assessed only for stormflow because the generally low concentrations of
metals and the high water hardness in baseflow generally lead to very few toxicity exceedances.
Additionally, toxicity exceedance was only assessed for Cu, Pb, and Zn. Exceedances were expressed as
a percent of storm samples exceeding the chronic standard and as the mean ratio of exceedances relative
to the chronic standard. For example, a mean exceedance ratio of 2 denotes that the mean concentration
of samples exceeding the standard was 2 times higher than the standard. The toxicity exceedance
percentages and ratios for all sites and all monitored years are summarized in Appendix B.
3.2.11 FEDERAL AND STATE SURFACE WATER QUALITY STANDARDS COMPARISON
Currently, there are no federal or state water quality standards for stormwater. The Minnesota Pollution
Control Agency (MPCA) and the U.S. Environmental Protection Agency (EPA) have established
surface water quality standards for only certain water quality parameters. Regardless, CRWD’s
stormwater flows into the Mississippi River, so it is useful to compare the stormwater data to surface
water quality standards which serve as a benchmark to consider for each pollutant (Table 3-5).
TP and TSS Standards
Because the MPCA has not established stormwater standards for TSS and TP, the data was compared to
the TP and TSS values of Lambert’s Landing, a Mississippi River water quality monitoring station
downstream of the Wabasha Bridge in St. Paul at river mile 839.1. Additionally, the TSS values were
compared against the South Metro Mississippi Total Suspended Solids TMDL, and the TP values were
compared against the Lake Pepin Excess Nutrient TMDL. When comparing CRWD TP and TSS
concentrations to water quality standards, flow-weighted average concentrations were used.
Chronic Metals Standards
State water quality standards for chronic exposure to metals are based on a function of hardness as
outlined in Minnesota Statute 7050.0222 for Class 2B waters. Class 2B waters are waters used for the
purpose of aquatic life and recreation that are not protected for drinking water. These standards are set
at the lowest concentration of a chemical for which chronic exposure will cause harm to aquatic
organisms. In order to make comparisons between CRWD metals data to state standards and other
reference locations, calculation of the state standards was completed.
Bacteria Standard
For E. coli bacteria, the MPCA has set the following two provisions as a standard:
2013 CRWD Stormwater Monitoring Report 20
1. With greater than five samples taken in a calendar month (April to November), the E. coli
concentration geometric mean shall be less than 126 cfu/100mL.
2. No more than ten percent of all samples taken during a calendar month (April to November)
shall exceed 1,260 cfu/100mL
CRWD collects a limited number of E. coli samples each month from April to November (two base
samples and occasional storm samples), so the MPCA monitoring requirements of the E. coli geometric
mean standard of 126 cfu/100mL cannot be typically met. Instead, CRWD compares individual E. coli
monitoring results to the maximum value of the standard, 1,260 cfu/100mL. This comparison provides a
benchmark only for comparing CRWD bacteria data and does not imply whether or not the full bacteria
standard is being met. The MCES lab measures E. coli as the most probable number per 100 milliliters
of water (mpn/100mL). Research shows that mpn/100mL is comparable to cfu/100mL (Massa et al.,
2001).
Table 3-5: Surface water quality standards for Class 2B waters.
Parameter Standarda Units Water Body Source
Cl 230 mg/L Surface Minn. Stat. § 7050.0222
Cd * mg/L Surface Minn. Stat. § 7050.0222
Cr * mg/L Surface Minn. Stat. § 7050.0222
Cu * mg/L Surface Minn. Stat. § 7050.0222
E. coli ≤ 1,260 MPN/100 mL Surface Minn. Stat. § 7050.0222
NH3 0.04 mg/L Surface Minn. Stat. § 7050.0222
Ni * mg/L Surface Minn. Stat. § 7050.0222
Pb * mg/L Surface Minn. Stat. § 7050.0222
TP 0.04 mg/L Surface Minn. Stat. § 7050.0222
TSS 30 mg/L Stream Draft Technical Support
Document (MPCA 2011)b
Zn * mg/L Surface Minn. Stat. § 7050.0222
*The standard is dependent upon water hardness; See Appendix B.
a Standards apply to Class 2B waters in the North Central Hardwood Forest ecoregion. Class 2B waters are
designated for aquatic life and recreational use. All standard concentrations apply to chronic exposure.
b In 2011, the MPCA released a Draft Technical Support Document providing support for proposed
amendments to Minn. Stat. § 7050 & 7052. Amendments are pending.
2013 CRWD Stormwater Monitoring Report 21
3.2.12 MISSISSIPPI RIVER REFERENCE SITE AND TWIN CITIES METRO-AREA TRIBUTARIES COMPARISONS
In addition to comparing CRWD results to state surface water quality standards, CRWD total TP and
TSS FWA concentrations were compared to the average TP and TSS concentrations of the Mississippi
River at Lambert’s Landing. MCES monitors the Mississippi River at Lambert’s Landing at river mile
839.1, which is downstream from the Wabasha Street Bridge in St. Paul.
MCES also monitors the mouths of several tributaries in the Minneapolis/St. Paul metropolitan area,
including Bassett Creek, Battle Creek, Fish Creek and Minnehaha Creeks. These are all open channels
that discharge to the Mississippi River. Total TP and TSS yields for CRWD subwatershed outlet sites
(East Kittsondale, Phalen Creek, St. Anthony Park, and Trout Brook Outlet) were compared to the yields
of these other metro-area tributaries to determine the relative impacts to the Mississippi River.
3.2.13 NATIONAL URBAN STORMWATER QUALITY COMPARISONS
Researchers from the University of Alabama and the Center for Watershed Protection have created an
extensive database of stormwater data from urbanized areas by assembling and evaluating stormwater
monitoring data from a representative number of National Pollutant Discharge Elimination System
(NPDES) Municipal Separate Storm Sewer System (MS4) Phase I stormwater permit holders. The
goals of the National Stormwater Quality Database (NSQD) are to describe the characteristics of
national stormwater quality, to provide guidance for future sampling needs, and to enhance local
stormwater management activities in areas having limited data.
Over nearly a ten-year period, stormwater quality data from 3,765 storm events and 65 municipalities in
17 states including Minnesota was assembled and entered into the first version of the NSQD (Maestre
and Pitt, 2005). The NSQD, Version 1.1 was extensively reviewed for quality assurance and control and
statistical analyses were performed to characterize and understand the pollutant data.
Although the NSQD, Version 1.1 includes only a small set of data from the midwest and northeast
portions of the country, which have similar climatic conditions, it still provides a useful comparison of
how polluted stormwater in CRWD is compared to the rest of the country. The database includes
stormwater quality data for various land use types. The predominant land uses in CRWD are mixed
residential, commercial, and industrial with 42% of the land comprised of impervious surfaces. CRWD’s
stormwater quality data was compared to the NSQD’s mixed residential land use category, which has a
median impervious percentage of 45%. Table 3-6 presents the NSQD median data values for the mixed-
residential land use category.
2013 CRWD Stormwater Monitoring Report 22
Table 3-6: NSQD stormwater pollutant median concentrations.
Parameter
Median Value
Area (acres) 150.8
% Impervious 44.9
Precipitation Depth (in.) 0.53
Escherichia coli (mpn/100mL) 1,050
Total Suspended Solids (mg/L) 66
Total Phosphorous (mg/L) 0.28
Ammonia (mg/L) 0.39
Nitrate+Nitrite (mg/L) 0.57
Total Kjeldahl Nitrogen (mg/L) 1.40
Cadmium (mg/L) 0.0009
Chromium (mg/L) 0.0070
Copper (mg/L) 0.0160
Lead (mg/L) 0.0160
Nickel (mg/L) 0.0078
Zinc (mg/L) 0.0950
2013 CRWD Stormwater Monitoring Report 23
4 CLIMATOLOGICAL SUMMARY
4.1 PRECIPTATION DATA COLLECTION METHODS
CRWD utilizes climatological data collected by the Minnesota Climatology Working Group (MCWG)
at the University of Minnesota-St. Paul and National Weather Service (NWS) at the Minneapolis-St.
Paul International Airport (MSP) to assist in calculating annual precipitation, runoff, and loading.
MCWG records precipitation every fifteen minutes from an automatic rain gauge located approximately
two miles west of the CRWD office. The data is reported on a public website (http://climate.umn.edu/).
Rainfall totals (15-minute and daily) were recorded by CRWD from the MCWG website. Snow and ice
totals were not accurately reported by MCWG, so they were not recorded by CRWD from this source.
The MCWG rain gauge was used as CRWD’s primary precipitation monitoring station because of the
gauge’s close proximity to the District.
The NWS weather station at MSP, located approximately ten miles south of the CRWD office, records
many climate variables for each day, including: maximum, minimum, and average temperature;
precipitation (including water amount in snow); snowfall; and depth of snowpack. Data is reported on a
public website (www.crh.noaa.gov/mpx/Climate/MSPClimate). NWS daily precipitation totals were
used if any snow or ice was logged as precipitation. Precipitation amounts as snow-water or ice-water
are more accurately measured at this station because of the type of snow measurement device used.
In 2013, the Trout Brook subwatershed exported the greatest amount of water (536,193,654 cf) because it has the largest drainage area in CRWD (8,000 acres) (Figure 5-1; Table 5-6). The 2013 total discharge for all monitored subwatersheds (with the exception of Phalen Creek) were greater than the historical averages of previous monitoring years (2005-2012) (Figure 5-1), largely due to an above average annual precipitation year. It is important to note that 5.28 inches of precipitation occurred during a period of equipment malfunction at Phalen Creek, so the resulting stormflow was not recorded. Thus, the discharge generated from this storm event was not accounted for in the discharge total, which is likely why Phalen Creek was the only site in 2013 that did not have a total discharge greater than its historical average. For the continuously monitored sites (St. Anthony Park, East Kittsondale, Phalen Creek, Trout Brook-East Branch, Trout Brook-West Branch, and Trout Brook Outlet), baseflow comprised the majority (52-77%) of the total annual discharge (Figure 5-2; Table 5-6). Stormflow accounted for less of the total annual discharge at the continuously monitored sites since precipitation is episodic and seasonal, whereas baseflow is constant and perennial. Snowmelt runoff in 2013 made up a larger than normal fraction of the total discharge at the continuously monitored sites due to a deep snowpack (68.9 inches) that accumulated during the winter 2012-2013 (Figure 5-2; Table 5-6). Throughout spring 2013, the snowpack melted slowly and diurnally with daily afternoon peaks and was not fully melted until April 23. At the seasonally monitored sites (Como 7 and Sarita), stormflow comprised the entire total annual discharge since these sites do not have baseflow (Figure 5-2; Table 5-6). Villa Park is also seasonally monitored, though it does have some baseflow. However, total discharge at Villa Park in 2013 was primarily driven by stormflow since the baseflow is minimal. Snowmelt events were not recorded at any of the seasonally monitored sites since snowmelt occurred prior to the flow monitoring equipment being installed spring 2013 (Table 3-3). Overall, the seasonally monitored sites record less total annual discharge than the continuously monitored sites since they do not have baseflow and they are monitored for a shorter time period (April to November).
Water Yield (cf/ac)
Water yield was calculated for each monitoring site by dividing the total annual discharge by subwatershed drainage area in order to make site-to-site comparisons possible. From this
2013 CRWD Stormwater Monitoring Report 32
calculation, Trout Brook-West Branch recorded the highest annual water yield (144,989 cf/ac) in comparison to all other continuously monitored sites in 2013 (Figure 5-3). Trout Brook-West Branch likely has the highest water yield because it has the most surface water connections in its subwatershed. Overall, all continuously monitored sites in 2013 recorded greater total water yields than historical averages (except for Phalen Creek due to equipment malfunction) (Figure 5-3). For the seasonally monitored sites, Villa Park had the highest annual water yield (22,301 cf/ac), which is likely related to baseflow contributions (unlike Como 7 or Sarita) (Figure 5-3). Sarita had the lowest annual water yield (9,193 cf/ac) of the seasonally monitored sites. The annual water yield at Como 7 (11,164 cf/ac) was similar to its historical average (Figure 5-3). The cumulative water yield plot (Figure 5-4) shows the increasing trends in annual water yield by site are directly related to large precipitation events in 2013. Combined, the large precipitation events on May 18-20 and June 21-23 produced 21% of the total annual precipitation in 2013, which accounted for either the majority or a very large fraction of the annual stormflow yield for all sites. Consequently, a large spike in annual water yield at each site is apparent for both storm events on the cumulative water yield plot (Figure 5-4). Conversely, a dry late-July through September resulted in insignificant increases in water yield during the fall, thus showing a decreased rate of increase on the cumulative yield plot (Figure 5-4).
2013 CRWD Stormwater Monitoring Report 33
Figure 5-1: Total discharge at CRWD monitoring sites in 2013 compared to historical averages.
2013 CRWD Stormwater Monitoring Report 34
Figure 5-2: Baseflow, stormflow, and snowmelt discharge totals at CRWD monitoring sites, 2013.
-
100,000,000
200,000,000
300,000,000
400,000,000
500,000,000
600,000,000
EastKittsondale
Phalen Creek St. AnthonyPark
Trout Brook-East Branch
Trout Brook-West Branch
Trout BrookOutlet
Como 7Subwatershed
Sarita Villa Park
Tota
l Dis
char
ge (c
f)
Site
Snowmelt
Storm
Base
*East Kittsondale, Trout Brook Outlet and Como 7 Illicit Discharges are a small percentage of Total Discharge and are not added to graph** Como 7 and Sarita do not have baseflow
2013 CRWD Stormwater Monitoring Report 35
Figure 5-3: Total water yield at CRWD monitoring sites in 2013 compared to historical averages.
2013 CRWD Stormwater Monitoring Report 36
Figure 5-4: Cumulative water yields for combined baseflow + stormflow at CRWD sites, 2013.
0
1
2
3
4
5
60
20,000
40,000
60,000
80,000
100,000
120,000
4/1 5/1 6/1 7/1 8/1 9/1 10/1 11/1
Prec
ip (i
n)
Cum
ulat
ive
Wat
er Y
ield
(ft3
/ac)
EK
PC
SAP
TBEB
TBWB
TBO
VPO
Sarita
Como 7
Combined Stormflow + Baseflow
2013 CRWD Stormwater Monitoring Report 37
5.1.2 TOTAL SUSPENDED SOLIDS (TSS)
TSS Loads (lbs)
At the sites with continuous monitoring (Phalen Creek, St. Anthony Park, Trout Brook-East Branch, Trout Brook-West Branch, and Trout Brook Outlet), stormflow was the largest contributor to the total TSS load at all sites (Figure 5-5), even though baseflow accounted for the majority of the total discharge (Figure 5-2). Baseflow generally has lower TSS concentrations because it includes flow contributions from groundwater, surface water, and permitted industrial discharges. In addition, velocity and flow volumes are lower during baseflow periods, so water does not have as much ability to carry solids. Stormwater contains more TSS because it washes off impervious surfaces. Also, sediment is less likely to settle out in water while in transport. In 2013, snowmelt was also a substantial contributor to the total annual TSS loads at the continuously monitored sites, especially in comparison to previous years. Generally, the snowmelt TSS load at the continuously monitored sites accounted for 4-18% of the total annual load. Phalen Creek had the highest percentage (18%; 80,533 lbs) of the total annual TSS load come from snowmelt runoff (Figure 5-5; Table 5-6). Of the continuously monitored sites, Trout Brook Outlet had the largest total annual TSS load (2,164,883 lbs) in 2013, of which 74% of the total load was transported by stormflow (Figure 5-5; Table 5-6). For the seasonally monitored sites, Sarita had the largest total annual TSS load (63,090 lbs), which was all transported by stormflow (Figure 5-5; Table 5-6).
TSS Yields (lbs/ac)
In comparison to all of the continuously monitored sites, the Trout Brook sites produced the highest total annual TSS yields on a per acre basis in 2013 and exceeded their historical average TSS yields (Figure 5-6; Figure 5-7). Trout Brook-West Branch recorded the highest annual TSS yield (713 lbs/ac) and Trout Brook-East Branch produced a TSS yield that was three-times greater than its historical average (Figure 5-6; Figure 5-7; Table 5-6). When normalized by inches of runoff, Trout Brook-East Branch subwatershed had the highest normalized yield (28 lb/ac/in runoff) of any site in 2013 and was more than twice its historical average of 11 lb/ac/in (Figure 5-8). Much of this increase in TSS can be attributed to a large road construction project in the Trout Brook-East Branch subwatershed. For the seasonally monitored sites, the total annual TSS yields in 2013 exceeded the historical averages at Como 7, Sarita, and Villa Park (Figure 5-6). When normalized by runoff, the 2013 total annual TSS yields from Como 7 (19 lbs/ac/in runoff) and Sarita (27 lbs/ac/in runoff) were comparable TSS yields produced by the larger subwatersheds, even though they do not have baseflow and runoff volumes are calculated entirely from stormflow ( Figure 5-8; Table 5-6). The stormflow resulting from the May 18-20 and June 21-23 events produced a significant portion of the TSS yield for all sites in 2013 (Figure 5-9). The trends in yield throughout the year closely follow the trends in stormflow water yield, highlighting the importance of stormflow as a driver of the TSS load in all CRWD subwatersheds.
2013 CRWD Stormwater Monitoring Report 38
Figure 5-5: Baseflow, stormflow, and snowmelt TSS load totals at CRWD monitoring sites, 2013.
0
400,000
800,000
1,200,000
1,600,000
2,000,000
2,400,000
EastKittsondale
Phalen Creek St. AnthonyPark
Trout Brook-East Branch
Trout Brook-West Branch
Trout BrookOutlet
Como 7Subwatershed
Sarita Villa Park
TSS
Load
(lbs
)
Site
Snowmelt
Storm
Base
*East Kittsondale, Trout Brook Outlet and Como 7 Illicit Discharges are a small percentage of TSS Load and are not added to graph** Como 7 and Sarita are sites that do not have any baseflow
2013 CRWD Stormwater Monitoring Report 39
Figure 5-6: Total TSS yields at CRWD monitoring sites in 2013 compared to historical averages.
2013 CRWD Stormwater Monitoring Report 40
Figure 5-7: Total TSS yields from CRWD subwatersheds, 2013.
2013 CRWD Stormwater Monitoring Report 41
Figure 5-8: Total normalized TSS yields at CRWD monitoring sites in 2013 compared to historical averages.
2013 CRWD Stormwater Monitoring Report 42
Figure 5-9: Cumulative TSS yields for combined baseflow + stormflow at CRWD sites, 2013.
0
1
2
3
4
5
6
70
100
200
300
400
500
600
700
4/1 5/1 6/1 7/1 8/1 9/1 10/1 11/1
Prec
ip (i
n)
Cum
ulat
ive
TSS
Yiel
d (lb
/ac)
EK
PC
SAP
TBEB
TBWB
TBO
VPO
Sarita
Como 7
Combined Stormflow + Baseflow
2013 CRWD Stormwater Monitoring Report 43
5.1.3 TOTAL PHOSPHORUS (TP)
TP Loads (lbs)
Like the TSS loads, stormflow was the dominant contributor of the total annual TP loads at all continuously monitored sites(Figure 5-10), even though baseflow accounted for the majority of the total discharge (Figure 5-2). Baseflow periods generally have lower TP concentrations because the discharge is driven by groundwater or surface water. In 2013, snowmelt runoff was a significant contributor to the total annual TP loads measured at the continuously monitored sites. At East Kittsondale, the total snowmelt TP load (302 lbs) exceeded total baseflow TP load (113 lbs) and nearly equaled the baseflow contribution at Phalen Creek (426 lbs) and St. Anthony Park (302 lbs) (Figure 5-10; Table 5-6). For the continuously monitored sites, Trout Brook Outlet produced the largest total annual TP load (5,077 lbs) in 2013, of which 54% of the total load was transported by stormflow (Figure 5-10; Table 5-6). For the seasonally monitored sites, Villa Park had the largest total annual TP load (343 lbs), which was also primarily transported by stormflow (73%) (Figure 5-10; Table 5-6).
TP Yields (lbs/ac)
In 2013, Trout Brook-West Branch produced the highest total annual TP yield (1.74 lb/ac) (Figure 5-11; Figure 5-12). Phalen Creek and East Kittsondale also had high annual TP yields (1.03 lbs/ac and 1.01 lbs/ac, respectively) in consideration of their small watershed sizes and high total impervious areas (Figure 5-11; Figure 5-12). The 2013 total annual TP yields from all District monitoring sites (with the exception of Phalen Creek) were higher than the historical averages (Figure 5-11). In particular, the 2013 TP yields from Trout Brook-East Branch, Como 7, Sarita, and Villa Park were significantly greater than their historical averages. Villa Park showed a 44% increase in total annual TP yield from its historical average (Figure 5-11). When normalized by subwatershed area and runoff, the TP yield from East Kittsondale has historically been the highest of all District sites, which has likely been due to the high percentage of total impervious surface area (46%) and the absence of storage in this subwatershed. In 2013, however, Trout Brook-East Branch produced the highest normalized TP yield (0.06 lb/ac/in runoff) of all the continuously monitored sites (Figure 5-13). Large road construction projects within the Trout Brook-East Branch subwatershed are likely the cause of some TP yield increases in comparison to the historical average. The normalized TP yields were close to the historical average for East Kittsondale, Phalen Creek, St. Anthony Park, Trout Brook-West Branch, and Trout Brook Outlet (Figure 5-13). For the seasonally monitored sites, Sarita had the highest normalized TP yield (0.08 lbs/ac/in runoff) (Figure 5-13; Table 5-6). A significant portion of the TP yield for all sites in 2013 was produced by the large storm events on May 18-20 and June 21-23 (Figure 5-14). Following July 2013, a decrease in monthly precipitation resulted in a relatively slow increase in TP yield from late July through September.
2013 CRWD Stormwater Monitoring Report 44
0
1,000
2,000
3,000
4,000
5,000
6,000
EastKittsondale
Phalen Creek St. AnthonyPark
Trout Brook-East Branch
Trout Brook-West Branch
Trout BrookOutlet
Como 7Subwatershed
Sarita Villa Park
TP L
oad
(lbs)
Site
Snowmelt
Storm
Base
*East Kittsondale, Trout Brook Outlet and Como 7 Illicit Discharges are a small percentage of TP Load and are not added to graph** Como 7 and Sarita are sites that do not have any baseflow
Figure 5-10: Baseflow, stormflow, and snowmelt TP load totals at CRWD monitoring sites, 2013.
2013 CRWD Stormwater Monitoring Report 45
Figure 5-11: Total TP yields at CRWD monitoring sites in 2013 compared to historical averages.
2013 CRWD Stormwater Monitoring Report 46
Figure 5-12: Total TP yields from CRWD subwatersheds, 2013.
2013 CRWD Stormwater Monitoring Report 47
Figure 5-13: Total normalized TP yields at CRWD monitoring sites in 2013 compared to historical averages.
2013 CRWD Stormwater Monitoring Report 48
Figure 5-14: Cumulative TP yields for combined baseflow + stormflow at CRWD sites, 2013
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ield
(lb/
ac)
EK
PC
SAP
TBEB
TBWB
TBO
VPO
Sarita
Como 7
Combined Stormflow + Baseflow
2013 CRWD Stormwater Monitoring Report 49
5.1.4 TOTAL NITROGEN (TN)
The stormflow yield trends for total nitrogen at all sites in 2013 closely followed the trends in TP yield. The May 18-20 and June 21-23 precipitation events produced the majority of the stormflow TN yield for all sites (Figure 5-15).The Trout Brook-West Branch and East Kittsondale yields, in particular, increased substantially in coincidence with the large storm events. At all sites, over half of the TN loading had occurred by late June. This is a significant deviation from the average seasonal loading trends which are more evenly distributed throughout the year. This is most likely due to the rainfall distribution in 2013.
Figure 5-15: Cumulative TN yields for combined baseflow + stormflow at CRWD sites, 2013.
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3
4
5
6
7
80
2
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4/1 5/1 6/1 7/1 8/1 9/1 10/1 11/1Pr
ecip
(in)
Cum
ulat
ive
TN Y
ield
(lb/
ac)
EK
PC
SAP
TBEB
TBWB
TBO
VPO
Sarita
Como 7
Combined Stormflow + Baseflow
2013 CRWD Stormwater Monitoring Report 50
5.1.5 CHLORIDE (CL-)
For sites with perennial baseflow, the baseflow Cl- yield historically makes up the large majority of the total annual Cl- yield, though trends in loading throughout the year are strongly related to seasonality. Cl- yields tend to peak during spring months when snowmelt carrying road salt from winter de-icing activities becomes runoff. In 2013, sites with baseflow showed a significant increase in Cl- yield from March to May coinciding with a long period over which the snowpack melted in 2013. Trout Brook-East Branch and Phalen Creek had the highest yield of Cl- in 2013 (Figure 5-16). Both Trout Brook-East Branch and Phalen Creek receive runoff from major interstate highways (I-35E and I-94, respectively), which may explain their high Cl- yields during spring snowmelt periods. Conversely, St. Anthony Park had the lowest loading rate. This is most likely due to stormwater storage and/or infiltration basins located within the subwatershed that store some of the Cl-.
Figure 5-16: Cumulative Cl- yields for combined baseflow + stormflow (with snowmelt) at CRWD sites, 2013.
The MPCA surface water standards for metals toxicity are a function of the water hardness of a sample; therefore, the standard is not a set value and is instead based on the water hardness measured at an individual monitoring site. Appendix B lists the equations used to calculate metal standards for cadmium, chromium, copper, lead, nickel, and zinc at each monitoring site as a function of measured water hardness levels. A table of the calculated standards for each individual site for all metals is also listed in Appendix B. Average annual toxicity of metals for each individual site were calculated for baseflow, snowmelt, stormflow, and total flow and compared to the MPCA standards. Additionally, percent exceedances and exceedance ratios were calculated for copper, lead, and zinc for storm events and summarized in Appendix B. Over the period of record, copper toxicity at all sites exceed the standard in 75%--99% of the stormflow samples, with the exception of Villa Park which only exceeded the standard 1% of the time. Over the period of record, lead toxicity at all sites exceed the standard in 83%--99% of the stormflow samples, with the exception of Villa Park which only exceeded the standard 11% of the time. Over the period of record, zinc toxicity at all sites exceed the standard in 20%--99% of the stormflow samples, with the exception of Villa Park which only exceeded the standard at no time during the period of record. Average baseflow metal toxicity never exceeded the MPCA toxicity standard at any site in 2013 for any of the 6 metals analyzed (Table 5-1). Toxicity exceedances are more common during storm conditions than baseflow due to the differences in hardness between the two flow conditions. The average storm toxicity in 2013 exceeded the MPCA toxicity standards for lead at all sites (except Como 7 and Villa Park) and copper at all sites (except Villa Park). Average stormflow toxicity of zinc exceeded the standard at East Kittsondale, St. Anthony Park and Como 7. For all sites, average toxicity of cadmium, chromium, and nickel for all flow types (base, snowmelt, storm, and yearly) did not exceed the MPCA toxicity standards in 2013.
2013 CRWD Stormwater Monitoring Report 52
Table 5-1: Metals toxicity and chronic toxicity standard exceedances at CRWD monitoring sites, 2013.
-- No data availableSee Appendix B for metals standards.
Nickel
Zinc
Cadmium
Chromium
Copper
Lead
2013 CRWD Stormwater Monitoring Report 53
5.1.7 BACTERIA
E. coli samples were collected during baseflow, snowmelt, stormflow, and illicit discharge periods. For baseflow periods, E. coli concentrations at most monitoring sites did not exceed the MPCA surface water maximum numeric standard of 1,260 cfu/100mL, with the exception of a few sites on isolated occurrences (East Kittsondale, Trout Brook-West Branch, Trout Brook Outlet, and Villa Park) (Table 5-2). During stormflow events, the majority of samples for all sites exceeded the MPCA maximum numeric standard of 1,260 cfu/100mL for bacteria (Table 5-3). Three samples out of a total of 25 samples at the nine monitoring sites were less than the maximum standard for E. coli bacteria. The maximum concentration at a subwatershed outlet occurred at St. Anthony Park on September 18th with a concentration of 125,900 cfu/100mL (Table 5-3) and the maximum concentration collected from any site occurred at Sarita on May 1 with a concentration of 1,553,100 cfu/100ml.
2013 CRWD Stormwater Monitoring Report 54
Table 5-3: Stormflow grab sample E. coli concentrations at CRWD monitoring sites, 2013.
Value exceeds MPCA maximum numeric standard (1,260 cfu/100mL).-- No sample collected
Storm Grab Sample Date
Site
Table 5-2: Baseflow grab sample E. coli concentrations at CRWD monitoring sites, 2013.
2013 CRWD Stormwater Monitoring Report 55
5.2 COMPARISON OF CRWD DATA TO METRO TRIBUTARIES
Compared to the yields of four other metro-area tributaries, all four of CRWD’s major subwatershed outlet sites (East Kittsondale, Phalen Creek, St. Anthony Park, and Trout Brook Outlet) produced a greater TSS yield per acre and a greater TP yield per acre (Figure 5-17 and Figure 5-19). When comparing discharge from CRWD outlets to other metro-area tributaries, it should be noted that the entire CRWD watershed is highly urbanized with water flowing in pipes instead of natural channels. In many of the other tributaries’ watersheds, discharge primarily flows in natural channels. Storm sewers operate differently than natural streams. When water velocity decreases, sediments settle out of the water column. In natural streams, this occurs when the stream meanders, flows through a vegetated area, gets wider, or reaches a relatively flat stretch. Storm sewers are designed to maintain velocity in the pipe; pipes have a set diameter, do not meander, and can change elevation quickly. In natural streams, nutrients are taken up by vegetation and algae, but there is no vegetation in storm sewers. As a result, most of the sediment and nutrients washed into storm sewers remain in the water column until the pipe reaches a body of water. Sediments and nutrients from streets and sidewalks are washed directly into the storm sewer and carried to the river. Average concentrations of TSS from all CRWD monitoring sites in 2013 exceeded the South Metro Mississippi River TSS TMDL goal of 32 mg/L. All but Phalen Creek and Villa Park exceeded Lamberts Landing concentrations (Figure 5-18). Additionally, all CRWD sites exceeded the Lake Pepin TMDL TP concentration goal of 0.10 mg/L. All sites except St. Anthony Park and Trout Brook Outlet exceeded average TP concentrations in the Mississippi River at Lamberts Landing (Figure 5-20).
2013 CRWD Stormwater Monitoring Report 56
Figure 5-17: TSS yields from CRWD subwatersheds compared to Twin Cities metro-area tributaries, 2013.
0
100
200
300
400
500
600
700
East Kittsondale Phalen Creek St. Anthony Park Trout Brook-EastBranch
Trout Brook-WestBranch
Trout Brook Outlet
Aver
age
TSS
Yiel
d (lb
/ac)
2013 Avg TSS yield(lb/ac)Basset Creek*
Battle Creek*
Fish Creek*
Minnehaha Creek*
* Water quality data for Twin Cities metro tributaries were collected by Metropolitan Council (MCES, 2013). Lines represent historical average annual TSS yields in lb/ac from 2005-2012.
2013 CRWD Stormwater Monitoring Report 57
0
50
100
150
200
EastKittsondale
Phalen Creek St. AnthonyPark
Trout Brook-East Branch
Trout Brook-West Branch
Trout BrookOutlet
Como 7Subwatershed
Sarita Villa Park
Flow
-Wei
ghte
d TS
S C
once
ntra
tion
(mg/
L)
Site
Historical Average
2013
a. Target TSS concentration for the South Metro Mississippi Total Suspended Solids TMDL: 32 mg/L: (MPCA, 2012b).b. Average TSS concentration at Lamberts Landing, 2002-2013: 56.7 mg/L (MCES, 2013).c. The historical average for continuously monitored sites is based on discharge data from 2010-2012. The historical average for seasonally monitored sites is based on discharge data from 2005-2012.
South Metro Mississippi TSS TMDLa
Lamberts Landingb
c
Figure 5-18: Average 2013 flow-weighted TSS concentrations from CRWD subwatersheds compared to Lamberts Landing and the South Metro Mississippi River TSS TMDL target concentration.
2013 CRWD Stormwater Monitoring Report 58
Figure 5-19: TP yields from CRWD subwatersheds compared to Twin Cities metro-area tributaries, 2013.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
East Kittsondale Phalen Creek St. Anthony Park Trout Brook-EastBranch
Trout Brook-WestBranch
Trout Brook Outlet
Aver
age
TP Y
ield
(lb/
ac)
2013 Avg TP yield(lb/acre)Basset Creek*
Battle Creek*
Fish Creek*
Minnehaha Creek*
* Water quality data for Twin Cities metro tributaries were collected by Metropolitan Council (MCES, 2013). Lines represent historical average annual TP yields in lb/ac from 2005-2012
2013 CRWD Stormwater Monitoring Report 59
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
EastKittsondale
Phalen Creek St. AnthonyPark
Trout Brook-East Branch
Trout Brook-West Branch
Trout BrookOutlet
Como 7Subwatershed
Sarita Villa Park
Flow
-Wei
ghte
d TP
Con
cent
ratio
n (m
g/L)
Site
Historical Average
2013
a. Target TP concentration for MPCA Lake Pepin Excess Nutrient TMDL: 0.10 mg/L (MPCA, 2013).b. Average TP concentration at Lamberts Landing, 2002-2013: 0.15 mg/L (MCES, 2013).c. The historical average for continuously monitored sites is based on discharge data from 2010-2012. The historical average for seasonally monitored sites is based on discharge data from 2005-2012.
Lake Pepin Excess Nutrients TMDLa
Lamberts Landingb
c
Figure 5-20: Average 2013 flow-weighted TP concentrations from CRWD subwatersheds compared to Lamberts Landing and the Lake Pepin Excess Nutrient TMDL target TP concentration.
2013 CRWD Stormwater Monitoring Report 60
Table 5-4: Pollutant standards and average concentrations at CRWD sites and the Mississippi River at Lamberts Landing, 2013.
5.3 COMPARISON OF CRWD STORMWATER DATA AND NSQD DATA
Table 5-3 compares 2013 stormwater pollutant median concentrations from CRWD and the National Stormwater Quality Database (NSQD). Compared to other urbanized areas in the country, CRWD 2013 stormwater median concentrations for TSS, TP, TKN and E. coli at the majority of sites exceeded NSQD median concentrations for mixed-residential areas. The NSQD median ammonia concentration was only exceeded at Villa Park. CRWD Nitrate+Nitrite median concentrations at all sites were below the NSQD median concentration of 0.39 mg/L. CRWD median metal concentrations only exceeded NSQD values at East Kittsondale and Trout Brook Outlet. East Kittsondale concentrations of copper lead and zinc and Trout Brook Outlet concentrations of chromium, copper, and lead were higher than NSQD data. None of the CRWD monitoring sites exceeded the NSQD value for nickel or cadmium.
Metropolitan Council Site
Standard (mg/L)
Lamberts Landing
East Kittsondale
Phalen Creek
St. Anthony
Park
Trout Brook Outlet
TPa 0.13 0.13 0.21 0.20 0.14 0.30TSSa 14 37 102 105 102 177Ammoniab 0.04 0.07 0.15 0.07 0.17 0.16TKNc N/A 1.11 1.6 1.2 1.3 1.7Nitratec N/A 1.65 1.03 1.51 0.83 0.62Nitritec N/A 0.04 0.04 0.03 0.04 0.05Cadmium * 0.00020 0.00022 0.00021 0.00028 0.00023Chromium * 0.00080 0.00388 0.00291 0.00309 0.00469Copper * 0.00170 0.01400 0.00779 0.01000 0.01133Lead * 0.00057 0.01194 0.01120 0.00699 0.01428Nickel * 0.00202 0.00313 0.00224 0.01390 0.00457Zinc * 0.00960 0.06746 0.04586 0.04375 0.04127Chlorided 230 30 181 85 158 107* The standard is dependent on w ater hardness; See Appendix B a There are no numeric standards for TP and TSS. These values are NCHF ecoregion averages from minimally
impacted streams.b Ammonia standard is based on un-ionized ammonia, w hich varies and is dependent on temperature and pHc There is no nitrate, nitrite, or TKN standard for surface w ater.d Chloride standards are from the MPCA.
All numbers are in mg/L.
Red Exceed/equal Lambert's Landing concentrations and the standard
Yellow Exceed/equal Lambert's Landing concentrations, but not the standard
2013 CRWD Monitoring Sites
Key
2013 CRWD Stormwater Monitoring Report 61
Table 5-5: CRWD 2013 median stormflow concentrations compared to NSQD median concentrations.
Table 5-6: Annual monitoring results summary for CRWD sites, 2013.
Como 7
2013 CRWD Stormwater Monitoring Report 63
6 COMO 7 SUBWATERSHED RESULTS
6.1 DESCRIPTION
The Como 7 subwatershed includes portions of the cities of St. Paul, Roseville, and Falcon Heights. Como 7 is one of eight minor subwatersheds within the Como Lake subwatershed and is located west of Como Lake. North of Como 7 is Como 8 subwatershed, which drains to Gottfried’s Pit, a stormwater retention pond. When the water level in Gottfried’s Pit reaches a specific level, a lift station pumps the water via storm sewer to the Como Golf Course Pond (part of the Como 7 subwatershed) before being discharged to Como Lake. CRWD monitors the Como 7 subwatershed to determine the aggregated or combined improvements to water quality based on the BMPs constructed as part of the Arlington-Pascal Stormwater Improvement Project. Started in 2005, the project included four stormwater BMP types: 1) eight infiltration trenches, 2) eight raingardens, 3) an underground infiltration and storage facility (Arlington-Hamline Underground Storage Facility), and 4) a stormwater pond at the Como Golf Course. These BMPs treat and infiltrate stormwater runoff, minimize localized flooding and reduce stormwater volumes in the storm sewer system. Three of the four BMPs (the Arlington-Hamline Underground Stormwater Storage Facility, eight in-street infiltration trenches and eight neighborhood raingardens), became operational in 2006 and 2007. The last BMP of the project, a storage and retention pond on the Como Park Golf Course (Como Golf Course Pond) became operational in October 2007.
Figure 6-1: The Como 7 monitoring station (left) and the Como Golf Course Pond Outlet (right).
Como 7
2013 CRWD Stormwater Monitoring Report 64
Como 7
2013 CRWD Stormwater Monitoring Report 65
6.2 2013 MONITORING SUMMARY
Prior to the Como Golf Course Pond becoming operational in October 2007, all flow from the Como 7 subwatershed to Como Lake passed through the Como 7 monitoring site. The Como 7 subwatershed results after October 2007 are the sum of the discharge and pollutant load data from two monitoring sites, Como 7 and the outlet of the Como Golf Course Pond. The Como 7 subwatershed has been monitored for flow and water quality since 2005, with the exception of 2006. Because the subwatershed does not have sustained yearly flow, it is generally monitored from early April to mid-November. In 2012, the Como Golf Course Pond was retrofitted to increase storage capacity and drainage from the surrounding fairways, and a new vegetative buffer was planted around the perimeter of the pond. During construction, the normal stormwater inflow to the pond was diverted entirely to Como 7 and therefore did not receive any pre-treatment by the pond. The 2013 Como 7 monitoring data from May 3 to June 25 includes all stormflow diverted from the Como Golf Course Pond in addition to the stormflow that would normally pass through the Como 7 monitoring site. After June 25, the pond was put back into service and flow was no longer diverted from the pond. On June 21, 2013, a large storm event dislodged the sensor from the storm sewer pipe. As a result, a portion of the data from the June 21 storm and all subsequent small events through June 28 were lost. The Como 7 monitoring site in 2013 recorded a regular (nearly daily) suspected illicit discharge into the storm sewer. The intervals are detailed in Table 6-3. The discharge represented approximately 2% of the monitored flow, 8% of the TP load and less than 0.5% of the TSS load for the subwatershed.
6.2.1 DISCHARGE
The 2013 discharge from the Como 7 subwatershed (8,853,099 cf) was the lowest discharge recorded since 2009 (Figure 6-3; Table 6-1). Three major factors may explain this observation. First, the rainfall total for the period in which equipment was installed in 2013 is also the lowest since 2009. Because all flow, with the exception of illicit discharges, is generated as a result of rainfall runoff (Como 7 does not have baseflow), it is expected that discharge and rainfall amount would be directly related. Second, the capacity of the Como Golf Course Pond was increased and the pond level was relatively low at the time the pond was brought back on line which may have served to buffer some of the discharge from the pond and its contribution to subwatershed flow. Third, Figure 6-4 shows that the water yield from the subwatershed in 2013 dropped below the historical average in late July, and stayed low through a drier than normal August and September. The amount of discharge from suspected illicit connections (192,354 cf) is fairly consistent year-to-year since the discharges were first identified in 2008. The Illicit discharges represent a small fraction (2%) of the total discharge each year (Figure 6-3; Table 6-1).
Como 7
2013 CRWD Stormwater Monitoring Report 66
Figure 6-3: Historical total monitored discharge volumes at Como 7 subwatershed for stormflow and illicit discharges from 2005-2013.
Figure 6-4: Historical and 2013 cumulative stormflow water yield from Como 7 subwatershed.
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Como 7
2013 CRWD Stormwater Monitoring Report 67
6.2.2 LOAD AND CONCENTRATION
Total Suspended Solids (TSS)
The 2013 TSS load (46,640 lbs) was one of the highest since the Como Golf Course Pond became fully operational for the 2008 monitoring season despite lower overall stormflow (Figure 6-5; Table 6-1). The majority of the precipitation in 2013 occurred during the period that flow was diverted away from the Como Golf Course Pond. As a result, that portion of the stormwater flow was not able to settle and drop its sediment load in the pond as it would have been able to in previous years. Figure 6-7 shows a clear drop in the rate of sediment yield accumulation after late June once flow was allowed to re-enter the Golf Course Pond. Figure 6-6 shows that monthly stormflow TSS concentrations in June and July 2013 were significantly higher than the historical average. The July concentration of 794 mg/L, in particular, was far above the average of 133 mg/L). Only two samples were taken in July 2013, one of which was considered an extreme outlier on the high end while the other was lower than the historical average for the month. While neither of these samples is likely representative of the average for the month, the data is presented here as-is.
Figure 6-5: Historical total monitored TSS loads at Como 7 subwatershed for stormflow and illicit discharges from 2005-2013.
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2013 CRWD Stormwater Monitoring Report 68
Figure 6-6: Monthly average storm sample TSS concentrations in 2013 for Como 7 subwatershed and historical averages (2008-2012).
Figure 6-7: Historical and 2013 cumulative stormflow TSS yield from Como 7 subwatershed.
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Como 7
2013 CRWD Stormwater Monitoring Report 69
Total Phosphorus (TP)
The 2013 TP load (159 lbs) was lower than the past three monitored years despite one of the highest total TSS loads recorded (Figure 6-8; Table 6-1). The monthly TP concentration data (Figure 6-9) shows that, with the exception of June, the 2013 concentrations were lower than the historical average. The concentrations for July through October, following the Como Golf Course Pond retrofits, were significantly lower than the average, suggesting some improved treatment from the pond after retrofitting. Figure 6-10 shows that the trends in TP yield throughout 2013 closely followed the trends in water yield (Figure 6-4) more than any other parameter. A decline in TP yield rate began in July accompanying a decline water yield rate. Future monitoring is needed to determine if TP concentrations and yield will continue to be reduced following pond retrofits.
Figure 6-8: Historical total monitored TP loads at Como 7 subwatershed for stormflow and illicit discharges from 2005-2013.
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2013 CRWD Stormwater Monitoring Report 70
Figure 6-9: Monthly average storm sample TP concentrations in 2013 for Como 7 subwatershed and historical averages (2008-2012).
Como 7
2013 CRWD Stormwater Monitoring Report 71
Figure 6-10: Historical and 2013 cumulative stormflow TP yield from Como 7 subwatershed.
Total Nitrogen (TN)
Total nitrogen yield from the Como 7 subwatershed is historically constant throughout the monitoring year (Figure 6-11). The 2013 TN yield closely followed the trend in water yield. A greater than average increase in 2013 occurred may through mid-July, and lower than average yields accompanied the dry period August through September. Overall, the TN yield was slightly less than the historical average.
Como 7
2013 CRWD Stormwater Monitoring Report 72
Chloride (Cl-)
Unlike sites that experience year-round baseflow, the chloride yield in the Como 7 subwatershed is entirely a result of snowmelt and stormflow. No clear seasonal trends are apparent in the historical yield data for the subwatershed (Figure 6-12). The 2013 yield was significantly less than the historical average, and may be a result of lower overall stormflow. Although the total yield was less than the average, the mid-May to mid-June rate of increase was very similar to the historical trend.
Figure 6-12: Historical and 2013 cumulative stormflow Cl- yield from Como 7 subwatershed.
Como 7
2013 CRWD Stormwater Monitoring Report 73
Table 6-1: Como 7 subwatershed monitoring results for 2005-2013.
Notes: Como 7 w as not monitored in 2006. Table includes data for Como 7 and Como Golf Course Pond Outlet monitoring sites and pumping from Gottfred's Pit located in the Como 7 subw atershed.
NA: Not available. Gottfried's Pit pumping w as not included in discharge calculations until 2013.
Como 7 Subwatershed Total Flow-Weighted Average 0.29 84 Como 7 Subwatershed Total 8,853,099 159 46,640
Note: Italics indicate estimated concentrations based on average historical monthly illicit discharge, Gottfried's pit, and storm flow concentrations.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 85
7 EAST KITTSONDALE SUBWATERSHED RESULTS
7.1 DESCRIPTION
The East Kittsondale subwatershed is located in the southern portion of CRWD and drains 1,116 acres of St. Paul (Figure 7-2). East Kittsondale is the smallest of the four major subwatersheds monitored by CRWD. The subwatershed empties into the Mississippi River, downstream of the confluence of the Minnesota and Mississippi Rivers. There are no surface water bodies in the subwatershed. Land use in the subwatershed is largely residential, with 46% impervious surface cover (CRWD, 2000). CRWD operates a full water quality monitoring station in the East Kittsondale subwatershed. Flow monitoring equipment is installed year-round while a water quality sampler is only installed for the non-winter monitoring period (April to early November). The station it is not located at the true outlet to the river because the depth of the storm sewer beneath the ground surface makes it difficult to monitor any further downstream.
Figure 7-1: The East Kittsondale monitoring site location (top, bottom left) and flow-logging and sampling equipment installed inside storm tunnel (bottom right).
East Kittsondale
2013 CRWD Stormwater Monitoring Report 86
Figure 7-2: Map of the East Kittsondale subwatershed and monitoring location.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 87
7.2 2013 MONITORING SUMMARY
The East Kittsondale subwatershed has been monitored for flow and water quality since 2005. From 2005 to 2008, monitoring only occurred during the spring, summer, and fall with no winter monitoring. Since 2009, the site has been monitored for the full calendar year with continuous flow data recorded and, at a minimum, one full water quality sampling event per month. Due to these differences in monitoring period, the 2009-2013 loading, and discharge data may show a significant difference when compared to pre-2009 data. Stormflow data should not be affected by differences in monitoring period as all storm samples since 2005 were collected during the spring, summer, or fall. The East Kittsondale monitoring site has a history of illicit discharges. In 2010, an illicit connection was identified and corrected. In 2012 possible illicit discharges were noticed during a dry period of the year. In 2013, greater attention was paid to the flow data during a dry period from August to October to identify and record potential illicit discharges. The identified intervals are detailed in Table 7-3. Overall illicit discharges represent a nearly insignificant portion of total flow and total loading in 2013. The flow data collected from East Kittsondale in 2013 is nearly 100% complete, meaning all possible data that could be collected was collected or adequately approximated.
7.2.1 DISCHARGE
In 2013 a larger fraction of the total discharge came from snowmelt compared to previous years (Figure 7-3). This is due in large part to a large snowpack depth in 2013 and a more protracted period in which snowmelt occurred. Another factor to note is that snowmelt was examined more closely when interpreting the 2013 flow data in comparison to previous years (see methods section). In 2009-2012 much of the runoff resulting from snowmelt was classified as baseflow. The historical average cumulative water yield for East Kittsondale (Figure 7-4) describes a relatively constant stormflow discharge throughout the year with increased flow occurring in early May and mid to late September. From May 17-20 2013 more than 4 inches of precipitation was recorded. The resulting storm flow accounted for approximately 18% of the total storm discharge recorded for 2013 and was a significant departure from the historical average. Large storm events June 20 to June 22 also resulted in a large increase from the historical average. A very dry August resulted in a 2013 total stormflow water yield close to the historical average.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 88
Figure 7-3: Historical total monitored discharge volumes at East Kittsondale subwatershed for baseflow, stormflow, snowmelt, and illicit discharges from 2005-2013.
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East Kittsondale
2013 CRWD Stormwater Monitoring Report 89
7.2.2 LOAD AND CONCENTRATION
Total Suspended Solids (TSS)
The majority of the suspended solids load for the entire monitoring record at East Kittsondale is overwhelmingly attributed to stormflow (Figure 7-5). The 2013 TSS load (408,699 lbs) was lower than all but two monitored years and the lowest since 2009 despite similar storm flow volume in 2009, 2011 and 2012 (Figure 7-7; Table 7-1). Although the stormflow volumes were not significantly different in 2013, Figure 7-6 shows that 2013 TSS storm concentrations were lower than the historical average throughout the year. The May, June, July, and September concentrations were markedly less than the historical average. The month of September was especially significant. The low TSS concentration and lower than average precipitation for the month can explain the low yearly load in 2013. Large storm events May 17-20, 2013 produced a large portion of the yearly TSS yield (Figure 7-7). Figure 7-7 shows that historically a large portion of the yearly TSS yield comes in mid-late September likely coinciding with leaf fall and related debris. This historical trend was not present in 2013. The baseflow yield in 2013 was higher than the average with a greater increase in yield occurring during the months of May and June (Figure 7-7). Since baseflow yields contribute a small fraction of the overall yield, the combined stormflow and baseflow yield was still well below the historical average.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 90
Figure 7-4: Historical and 2013 cumulative water yield from East Kittsondale subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 91
Figure 7-5: Historical total monitored TSS loads at East Kittsondale subwatershed for baseflow, stormflow, snowmelt, and illicit discharges from 2005-2013.
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East Kittsondale
2013 CRWD Stormwater Monitoring Report 92
Figure 7-6: Monthly average storm sample TSS concentrations in 2013 for East Kittsondale subwatershed and historical averages (2005-2012).
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East Kittsondale
2013 CRWD Stormwater Monitoring Report 93
Figure 7-7: Historical and 2013 cumulative TSS yield from East Kittsondale subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 94
Total Phosphorus (TP)
As with the TSS load, the majority of the yearly TP load at East Kittsondale is historically attributed to storm events (Figure 7-8). The total TP load for 2013 (1,125 lbs) is one of the highest on record; higher than all but 2007 and 2010 (Figure 7-8; Table 7-1). The contribution of stormflow to the total, however, is lower or nearly equal to most years in the historical record (Figure 7-8). In 2013 snowmelt was a major contributor to the total load (26%). It is important to note that throughout the nine year monitoring record, only one snowmelt sample was taken at East Kittsondale. In Figure 7-8 the 2013 load was calculated using this one sample concentration applied to all snowmelt intervals. In 2012, an average storm concentration was used to calculate the snowmelt yield. Therefore it is not possible to draw any solid conclusions about the contribution of snowmelt to the yearly TP load at this site. The lower than average 2013 stormflow load is reflected in the monthly storm TP concentrations (Figure 7-9). The average TP concentration for each month in 2013 was lower than the historical average. The June average (0.26 mg/L) was less than half of the historical concentration (0.67 mg/L). The month of June experienced heavy precipitation, but lower than average concentrations resulted in a reduced contribution to the overall load.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 95
Figure 7-8: Historical total monitored TP loads at East Kittsondale subwatershed for baseflow, stormflow, snowmelt, and illicit discharges from 2005-2013.
Heavy precipitation and subsequent stormflow May 17-20, 2013 resulted in a pronounced increase in stormflow TP yield (Figure 7-10). However, a drier than normal August and September resulted in a yearly stormflow yield close to the historical average. As with TSS yield, the baseflow yield in 2013 was greater than the historical average, but due to the lower overall contribution of baseflow to the total, the combined yield was slightly less than the historical value (Figure 7-10).
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East Kittsondale
2013 CRWD Stormwater Monitoring Report 96
Figure 7-9: Monthly average storm sample TP concentrations in 2013 for East Kittsondale subwatershed and historical averages (2005-2012).
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East Kittsondale
2013 CRWD Stormwater Monitoring Report 97
Figure 7-10: Historical and 2013 cumulative TP yield from East Kittsondale subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 98
Total Nitrogen (TN)
Historically, TN yield trends have mirrored those of TP. Baseflow yields tend to remain constant throughout the year with a drop in late October. Stormflow yield is historically constant throughout the year with a sharp increase in late September to early October (Figure 7-11). In 2013, the baseflow yield was significantly higher than the historical average in May and June which contributed to a total yearly baseflow yield higher than the average of previous monitoring years. Large increases in stormflow TN yield resulted from large storm events mid-May and mid-June in 2013. As with TP, a dry fall led to stormflow yields less than the historical average for this period. Additionally, there was not a pronounced increase in yield late September. The 2013 overall TN yield was slightly higher than average owing to higher baseflow yields.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 99
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Figure 7-11: Historical and 2013 cumulative TN yield from East Kittsondale subwatershed forstormflow, baseflow, and combined baseflow + stormflow.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 100
Chloride (Cl-)
Chloride yields tend to show clear seasonal variation and are greatly driven by activities in the watershed such as road salt application. Unlike other reported parameters, the majority of the yearly Cl- yield comes from baseflow. Historically, baseflow yields increase sharply in March and April, typically when the winter snowpack melts. Snowmelt was largely classified as baseflow in 2009-2012, so it is unclear which fraction of the yield is due to snowmelt runoff as opposed to the groundwater sourced baseflow. In 2013, however, when snowmelt was carefully separated from baseflow, the baseflow Cl- yield still showed a sharp increase coinciding with the melting of the snowpack. The 2013 increase in yield, though still marked, was more gradual than the historical average (Figure 7-12). The snowpack in 2013 melted over a time span of nearly two months, which was not typical of recent years, and may have resulted in the more gradual increase in yield. Future monitoring is necessary to determine if the more gradual increase seen in 2013 is a better representation of actual baseflow Cl- yields.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 101
Figure 7-12: Historical and 2013 cumulative Cl- yield from East Kittsondale subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 102
2005 2006 2007 2008 2009 2010 2011 2012 2013Subwatershed Area (ac) 1,116 1,116 1,116 1,116 1,116 1,116 1,116 1,116 1,116Total Rainfall (inches) 29.28 24.13 13.96 18.89 20.95 35.61 33.62 30.26 36.36Number of Monitoring Days 200 210 225 217 277 325 365 360 365Number of Storm Sampling Events 18 15 25 12 25 19 13 20 22Number of Storm Intervals 23 26 43 37 58 54 34 40 40Number of Snowmelt Sampling Events NA NA NA NA NA NA 0 0 1Number of Snowmelt Intervals NA NA NA NA NA NA 0 3 37Number of Illicit Discharge Sampling Events NA NA NA NA 8 0 0 0 3Number of Illicit Discharge Intervals NA NA NA NA 41 0 0 0 14Number of Base Sampling Events 1 8 11 11 25 20 18 17 15Number of Baseflow Intervals 41 21 42 38 82 58 34 45 84Total Discharge (cf) 27,816,625 39,689,928 58,852,320 35,342,806 44,095,386 66,983,674 76,282,660 55,261,249 72,017,156 Storm Flow Subtotal (cf) 21,125,831 25,397,422 45,045,199 24,635,756 30,705,350 50,937,930 36,668,961 36,530,284 32,265,441 Snowmelt Subtotal (cf) NA NA NA NA NA NA 0 5,740,510 14,504,314 Illicit Discharge Subtotal (cf) NA NA NA NA 4,211,844 0 0 0 133,811 Baseflow Subtotal (cf) 6,690,794 14,292,506 13,806,121 10,707,050 9,178,141 16,045,744 39,613,699 12,990,455 25,113,590 Average TSS Concentration (mg/L) 133 171 279 169 100 106 117 84 102Total FWA TSS Concentration (mg/L) 132 173 316 214 112 185 122 123 91Storm FWA TSS Concentration (mg/L) 133 266 403 291 141 241 243 160 184Snowmelt FWA TSS Concentration (mg/L) NA NA NA NA NA NA 0 157 22Illicit Discharge FWA TSS (mg/L) NA NA NA NA 98 0 0 0 25Base FWA TSS Concentration (mg/L) 4 6 32 36 20 7 10 5 11Total TSS Loading (lbs) 230,190 427,494 1,161,807 471,176 308,358 773,129 580,026 425,599 408,699Storm TSS Loading (lbs) 228,519 421,821 1,134,452 447,229 271,189 766,063 555,801 365,152 371,464Snowmelt TSS Loading (lbs) NA NA NA NA NA NA 0 56,334 19,920Illicit Discharge TSS Load (lbs) NA NA NA NA 25,722 0 0 0 209Base TSS Loading (lbs) 1,671 5,673 27,354 23,877 11,360 7,066 24,225 4,113 17,106Total TSS Yield (lb/ac) 206 383 1,038 422 276 693 520 381 366Normalized Total TSS Yield (lb/ac/in runoff) 30 39 71 48 25 42 28 28 21Average TP Concentration (mg/L) 0.31 0.37 0.35 0.39 0.29 0.25 0.17 0.19 0.21Total FWA TP Concentration (mg/L) 0.23 0.38 0.35 0.48 0.29 0.34 0.19 0.25 0.25Storm FWA TP Concentration (mg/L) 0.28 0.54 0.44 0.58 0.35 0.43 0.32 0.30 0.35Snowmelt FWA TP Concentration (mg/L) NA NA NA NA NA NA 0.00 0.31 0.33Illicit Discharge FWA TP (mg/L) NA NA NA NA 0.18 0.00 0.00 0.00 0.13Base FWA TP Concentration (mg/L) 0.06 0.08 0.08 0.24 0.16 0.06 0.07 0.05 0.07Total TP Loading (lbs) 398 931 1,302 1,058 801 1,425 886 845 1,125Storm TP Loading (lbs) 373 861 1,236 898 662 1,369 724 690 710Snowmelt TP Loading (lbs) NA NA NA NA NA NA 0 111 302Illicit Discharge TP Load (lbs) NA NA NA NA 49 0 0 0 1Base TP Loading (lbs) 25 70 66 161 90 56 162 44 113Total TP Yield (lb/ac) 0.36 0.83 1.17 0.95 0.72 1.28 0.79 0.76 1.01Normalized Total TP Yield (lb/ac/in runoff) 0.05 0.09 0.08 0.11 0.07 0.08 0.04 0.06 0.06
NA: Not available. Illicit discharge events w ere not monitored or sampled until 2009. Snow melt events w ere not monitored or sampled until 2011.
Table 7-1: East Kittsondale subwatershed monitoring results for 2005-2013.
East Kittsondale
2013 CRWD Stormwater Monitoring Report 103
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Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan 2014
2013 East KittsondaleLevel, Velocity, and Discharge
Total Flow-Weighted Average 0.25 91 Total 72,017,156 1,125 408,699
Note: Italics indicate estimated concentrations based on average historical monthly base, snowmelt and storm flow concentrations.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 111
8 PHALEN CREEK SUBWATERSHED RESULTS
8.1 DESCRIPTION
The Phalen Creek subwatershed is the eastern-most subwatershed in CRWD (Figure 8-2). Located entirely within the city limits of St. Paul, Phalen Creek drains 1,433 acres and outlets to the Mississippi River. CRWD monitors the Phalen Creek storm sewer near its outlet to the Mississippi River at the Bruce Vento Nature Sanctuary. Land use in the Phalen Creek subwatershed is a mix of industrial, commercial, and residential with approximately 50% impervious surfaces (CRWD, 2000).
Figure 8-1: The Phalen Creek monitoring site location (left), flow-logging and sampling equipment installed inside storm tunnel (top right), and open channel entrance (bottom right).
Phalen Creek
2013 CRWD Stormwater Monitoring Report 112
Figure 8-2: Map of the Phalen Creek subwatershed and monitoring location.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 113
8.2 2013 MONITORING SUMMARY
The Phalen Creek subwatershed has been monitored for flow and water quality since 2005. From 2005 to 2008, monitoring only occurred during the spring, summer, and fall. In 2009, monitoring occurred from April to December and beginning in 2010, the subwatershed has been monitored for the full calendar year recording continuous flow data. Since 2010, one full water quality sample, at a minimum, has been collected each month. Due to these differences in monitoring period, the 2010-2013 loading and discharge data may show significant differences when compared to pre-2010 data. Stormflow data should not be affected by differences in monitoring period as all storm samples since 2005 were collected during the spring, summer, or fall. The Phalen Creek monitoring site is located close to the storm sewer’s outfall to the Mississippi River. The river occasionally backs up into the pipe interfering with the accuracy of the flow measurements. In 2013, continuous flow data was recorded for 342 out of 365 possible days. Long periods of missing data occurred May 19 to June 3 and December 27-28, 2013. In both cases the sensor became disconnected from the logger as a result of conditions in the storm sewer. Stormflow volume and pollutant loads were not calculated during these periods of missing data.
8.2.1 DISCHARGE
Total, stormflow, and baseflow discharge in 2013 were the lowest recorded since full year monitoring began in 2010 (Figure 8-3; Table 8-1). During the missing data period of May 19 to June 3, 5.28 inches of precipitation occurred and the resulting stormflow is not accounted for in the discharge total. The cumulative water yield (Figure 8-4) at Phalen Creek does not show the sharp increase in yield May 17-20 that other district monitoring sites show. This again is due to the large missing data period May 19 to June 3. The stormflow water yield shows a greater increase in mid-late June than the historical average with a lower than average yield July to October. Baseflow water yield in 2013 very closely followed the historical trend. Combined baseflow and stormflow yield was close to the historical average.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 114
Figure 8-3: Historical total monitored discharge volumes at Phalen Creek subwatershed for baseflow, stormflow, and snowmelt from 2005-2013.
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Phalen Creek
2013 CRWD Stormwater Monitoring Report 115
Figure 8-4: Historical and 2013 cumulative water yield from Phalen Creek subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 116
8.2.2 LOAD AND CONCENTRATION
Total Suspended Solids (TSS)
The baseflow TSS load (33,197 lbs) decreased in 2013 compared to 2010-2012 (Figure 8-5; Table 8-1), while the overall load increased over the past two years. In 2013, snowmelt represented a larger fraction of the overall TSS load (18%) compared to 2011 and 2012 (snowmelt was only accounted for in these two additional years). 2013 had a large snowpack and snowmelt occurred over a more prolonged period of time than recent years. Storm concentrations of TSS in 2013 from April to July were significantly lower than the historical average (Figure 8-6). More than 60% of the yearly precipitation in 2013 occurred from April to July. The low TSS concentrations combined with a majority of the stormflow resulted in stormflow TSS loading lower than all monitored years with the exception of 2010. Historically, stormflow TSS yields are relatively constant throughout the year with sharp increases in mid-September to early October coinciding with leaf fall (Figure 8-7). In 2013, significantly less than average stormflow yields occurred from July to October due to less than average precipitation during this period (Figure 8-7).
Figure 8-5: Historical total monitored TSS loads at Phalen Creek subwatershed for baseflow, stormflow, and snowmelt from 2005-2013.
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
2005 2006 2007 2008 2009 2010 2011 2012 2013
TS
S L
oad
(lb
s)
Year
Snowmelt
Storm
Base
Phalen Creek
2013 CRWD Stormwater Monitoring Report 117
Figure 8-6: Monthly average storm sample TSS concentrations in 2013 for Phalen Creek subwatershed and historical averages (2005-2012).
n=5
n=7
n=17
n=22
n=24
n=23
n=17
n=13
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S C
on
cen
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g/L
)
Month
Historical Average (2005-2012)
2013
Phalen Creek
2013 CRWD Stormwater Monitoring Report 118
Figure 8-7: Historical and 2013 cumulative TSS yield from Phalen Creek subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 119
Total Phosphorus (TP)
The total TP load (1,483 lbs) in 2013 was similar to 2011 and 2012 (Figure 8-8; Table 8-1). Snowmelt represented a significant portion of the load (28%) in contrast to 2011 and 2012 while both stormflow and baseflow represented a reduced fraction of the load in 2013. Monthly stormflow TP concentrations in 2013 were less than the historical average for all months except August (Figure 8-9). The high August TP sample concentrations coincide with high TSS sample concentrations illustrating the link between sediment and phosphorus. The total phosphorus cumulative loading plot (Figure 8-10) shows a more pronounced increase in stormflow TP yields mid-May and mid-late June than the historical average. This is due in large part to uncharacteristically high precipitation during these periods in 2013. Historically, stormflow TP yields increase sharply in mid-September and early October coinciding with leaf fall (Figure 8-10). In 2013 these late season increases were less pronounced and occurred later in the year than the average. A relatively average baseflow yield combined with lower than average stormflow yields July to September resulted in an overall TP yield less than the historical average in 2013.
Figure 8-8: Historical total monitored TP loads at Phalen Creek subwatershed for baseflow, stormflow, and snowmelt from 2005-2013.
0
500
1,000
1,500
2,000
2,500
2005 2006 2007 2008 2009 2010 2011 2012 2013
TP
Lo
ad (
lbs)
Year
Snowmelt
Storm
Base
Phalen Creek
2013 CRWD Stormwater Monitoring Report 120
Figure 8-9: Monthly average storm sample TP concentrations in 2013 for Phalen Creek subwatershed and historical averages (2005-2012).
n=5
n=7
n=1
7
n=2
2
n=2
4
n=2
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TP
Co
nce
ntr
atio
n (
mg
/L)
Month
Historical Average (2005-2012)
2013
Phalen Creek
2013 CRWD Stormwater Monitoring Report 121
Figure 8-10: Historical and 2013 cumulative TP yield from Phalen Creek subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 122
Total Nitrogen (TN)
The 2013 yearly trends in TN yield closely mirror those of TP. Baseflow yield was relatively constant throughout 2013 mimicking the historical average. Stormflow TN yield at Phalen Creek is historically constant throughout the year with slight increases in mid-September and early October (less pronounced than TP). In 2013, stormflow TN yield increased dramatically over the historical average during mid-May storm events and a relatively wet June. A drier fall resulted in 2013 combined yields close to the historical average (Figure 8-11).
Phalen Creek
2013 CRWD Stormwater Monitoring Report 123
Figure 8-11: Historical and 2013 cumulative TN yield from Phalen Creek subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 124
Chloride (Cl-)
Chloride yields are seasonally related and largely driven by activities within the watershed such as road salt application. Historically stormflow Cl- yields at Phalen Creek are relatively constant with an increase in late October possibly related to early snowfall and subsequent road salt application. In 2013, the stormflow Cl- yield in April was significantly higher than the historical average (Figure 8-12). In 2013, the snowpack persisted into mid-April with snowmelt occurring throughout the month washing road salt off the landscape. Additionally, snow and freezing rain type precipitation persisted throughout April which necessitated further salt application. Unlike other water quality parameters reported on, baseflow yields of Cl- at Phalen Creek are not historically constant throughout the year (Figure 8-12). Baseflow also represents the majority of the yearly load of Cl-. Historically, Cl-, likely in the form of road salt, makes its way into baseflow with the majority of the baseflow yield occurring January to late March. In 2013, the baseflow Cl- yield followed the historical trend, with slightly lower yields in March and April.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 125
Figure 8-12: Historical and 2013 cumulative Cl- yield from Phalen Creek subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 126
Table 8-1: Phalen Creek subwatershed monitoring results for 2005-2013.
2005 2006 2007 2008 2009 2010 2011 2012 2013Subwatershed Area (ac) 1,433 1,433 1,433 1,433 1,433 1,433 1,433 1,433 1,433Total Rainfall (inches) 29.28 24.13 13.96 17.73 20.34 36.32 33.62 29.73 31.20Number of Monitoring Days 197 194 134 210 262 362 365 348 342Number of Storm Sampling Events 15 7 16 17 18 22 6 18 18Number of Storm Intervals 23 15 22 38 33 55 29 40 43Number of Snowmelt Sampling Events NA NA NA NA NA NA 6 2 1Number of Snowmelt Intervals NA NA NA NA NA NA 8 13 17Number of Baseflow Sampling Events 4 9 7 14 16 14 21 19 15Number of Baseflow Intervals 35 18 19 38 32 54 43 55 56Total Discharge (cf) 88,688,082 74,856,833 64,631,475 97,607,350 106,837,331 173,450,665 179,835,227 161,506,783 147,100,294Storm Flow Subtotal (cf) 28,075,754 14,451,216 25,260,005 29,007,153 30,113,506 50,698,610 38,703,641 41,442,850 32,392,177Snowmelt Flow Subtotal (cf) NA NA NA NA NA NA 9,361,953 3,153,892 15,527,373Baseflow Subtotal (cf) 60,612,328 60,405,617 39,371,470 68,600,197 76,723,824 122,752,055 131,769,633 116,910,040 99,180,744Average TSS Concentration (mg/L) 289 183 103 169 136 204 34 68 105Total FWA TSS Concentration (mg/L) 185 115 105 70 80 112 28 42 49Storm FWA TSS Concentration (mg/L) 535 454 164 207 277 369 92 141 165Snowmelt FWA TSS Concentration (mg/L) NA NA NA NA NA NA 53 78 83Base FWA TSS Concentration (mg/L) 23 34 3 11 3 5 8 6 5Total TSS Loading (lbs) 1,022,726 538,550 422,175 423,925 535,477 1,209,635 316,563 423,213 448,171Storm TSS Loading (lbs) 937,202 409,501 415,784 375,408 520,356 1,167,829 221,169 365,001 334,441Snowmelt TSS Loading (lbs) NA NA NA NA NA NA 30,974 15,357 80,533Base TSS Loading (lbs) 85,524 129,049 6,391 48,517 15,121 41,806 64,419 42,855 33,197Total TSS Yield (lb/ac) 714 376 295 296 374 844 221 295 313Normalized Total TSS Yield (lb/ac/in runoff) 42 26 24 16 18 25 6 10 11Average TP Concentration (mg/L) 0.39 0.29 0.20 0.39 0.30 0.35 0.16 0.21 0.20Total FWA TP Concentration (mg/L) 0.22 0.20 0.17 0.17 0.17 0.19 0.13 0.15 0.16Storm FWA TP Concentration (mg/L) 0.57 0.57 0.34 0.44 0.48 0.54 0.28 0.33 0.33Snowmelt FWA TP Concentration (mg/L) NA NA NA NA NA NA 0.27 0.39 0.44Base FWA TP Concentration (mg/L) 0.07 0.20 0.06 0.06 0.05 0.05 0.08 0.07 0.06Total TP Loading (lbs) 1242 914 674 1,033 1,157 2,104 1,474 1,470 1,483Storm TP Loading (lbs) 993 518 536 796 902 1,706 667 864 672Snowmelt TP Loading (lbs) NA NA NA NA NA NA 157 77 426Base TP Loading (lbs) 249 396 138 237 255 398 650 530 385Total TP Yield (lb/ac) 0.87 0.64 0.47 0.72 0.81 1.47 1.03 1.03 1.03Normalized Total TP Yield (lb/ac/in runoff) 0.05 0.04 0.04 0.04 0.04 0.04 0.03 0.03 0.04
NA: Not available. Snow melt events w ere not monitored or sampled until 2011.
Base 0.06 2 12/28/2013 00:00 12/31/2013 23:45 1,027,700 4.07 139 Snowmelt Flow-Weighted Average 0.44 83 Snowmelt Subtotal 15,527,373 426 80,533
Storm Flow-Weighted Average 0.33 165 Storm Subtotal 32,392,177 672 334,441
Base Flow-Weighted Average 0.06 5 Base Subtotal 99,180,744 385 33,197
Total Flow-Weighted Average 0.16 49 Total 147,100,294 1,483 448,171
Note: Italics indicate estimated concentrations based on average historical monthly base, snowmelt and storm flow concentrations.
Phalen Creek
2013 CRWD Stormwater Monitoring Report 134
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 135
9 ST. ANTHONY PARK SUBWATERSHED RESULTS
9.1 DESCRIPTION
The St. Anthony Park subwatershed has a drainage area of 3,418 acres and is the western-most subwatershed monitored by CRWD. CRWD monitors the storm sewer outlet of the St. Anthony Park subwatershed where it directly flows into the Mississippi River at Desnoyer Park in St. Paul (Figure 9-2). The subwatershed is primarily comprised of industrial and residential land uses with 48% impervious surface land coverage. CRWD also monitors a 929 acre upland subwatershed of St. Anthony Park called Sarita. The Sarita subwatershed is monitored in a storm sewer at the outlet of the Sarita Wetland near Como Avenue (Figure 9-2). The Sarita subwatershed has substantially different land use than any other CRWD subwatershed because it encompasses the Minnesota State Fair Grounds and the University of Minnesota St. Paul Campus where open space dominates. The predominant land use within the Sarita subwatershed is institutional with 16% impervious surface coverage.
Figure 9-1: The St. Anthony Park monitoring site location (left, top right); and Sarita Outlet monitoring site location (bottom right).
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 136
Figure 9-2: Map of the St. Anthony Park subwatershed and monitoring location.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 137
9.2 2013 MONITORING SUMMARY – ST. ANTHONY PARK
The St. Anthony Park site has been monitored for flow and water quality since 2005, with year-round monitoring beginning in 2009. Beginning in 2009, flow monitoring equipment was installed for the full calendar year and a minimum of one full water quality sample has been collected and analyzed each month. Due to these differences in monitoring period, the 2009-2013 load and discharge data may show a significant difference when compared to pre-2009 data. Stormflow data should not be affected by differences in monitoring period as all storm samples since 2005 were collected during the spring, summer, or fall. The St. Anthony Park monitoring site is located directly at the outfall to the Mississippi River. Its close proximity to the river can make monitoring difficult because of the influence of the river which often backs up into the storm sewer. The storm sewer has a steep gradient resulting in very high velocity flows during storm events. These high velocities increase the risk of monitoring equipment becoming dislodged or damaged. Because of equipment issues and site characteristics, significant portions of data have been lost each year. 22 days of discharge data from June 21 to July 12 2013 was lost after the sensor became dislodged from the bottom of the storm sewer channel. Discharge and loads are not calculated for missing data periods. With 351 days monitored, the 2013 dataset is the most complete yearly record collected at St. Anthony Park.
9.2.1 DISCHARGE
2013 had the highest recorded total discharge volume (147,100,294 cf) since full-year monitoring began in 2010. Baseflow historically makes up the majority of the total discharge at St. Anthony Park and the 2013 baseflow discharge (99,180,744 cf) was also the highest recorded since 2009 (Figure 9-3; Table 9-1). 2013 has a more complete yearly record than previous years, which partly explains these observations. However, greater snowpack in 2013 likely contributed to greater groundwater recharge and therefore higher baseflow volumes.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 138
Figure 9-3: Historical total monitored discharge volumes at St. Anthony Park subwatershed for baseflow, stormflow, and snowmelt from 2005-2013.
0
50,000,000
100,000,000
150,000,000
200,000,000
250,000,000
2005 2006 2007 2008 2009 2010 2011 2012 2013
Dis
char
ge (c
f)
Year
Snowmelt
Storm
Base
Seasonally Monitored (~Apr-Nov)
Continuously Monitored (Jan-Dec)
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 139
Figure 9-4: Historical and 2013 cumulative water yield from St. Anthony Park subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 140
9.2.2 LOAD AND CONCENTRATION
Total Suspended Solids (TSS)
The St. Anthony Park storm sewer tunnel passes through bedrock composed of St. Peter Sandstone. The tunnel has a concrete liner, but cracks and holes allow sandstone to be washed into the tunnel and into the Mississippi River. This sandstone contributes to both stormflow and baseflow TSS loading. A repair project was begun in 2010 and Figure 9-5 shows that TSS loading has decreased each year since 2010, with the exception of 2013 which shows a sharp increase in load. The repair project is expected to be completed in 2014 and future monitoring will show the impacts, if any, of the repair work. The 2013 storm load is one of the highest on record. No analysis was conducted to determine if this was a function of increased monitoring period. The baseflow load in 2013 showed a decrease from recent years. Despite a high storm TSS load, the monthly average storm TSS concentrations in 2013 were lower than the historical average with the exception of August (Figure 9-6). The total number of storm samples taken in 2013 (8 samples) is low compared to previous years, in particular 2005-2010 (Table 9-1). Because each month had a low number of storm samples in 2013, comparison to the historical data should be made with caution. The St. Anthony Park cumulative yield plots (Figure 9-7) show that historically both stormflow and baseflow TSS yields are fairly constant throughout the year with increases occurring in late April and late September. In 2013, the May 17 to May 20 events produced a large increase in TSS yield; far greater than the historical average for the time of year. The remainder of 2013 produced lower than average yields and the overall TSS yield was significantly less than the historical average.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 141
Figure 9-5: Historical total monitored TSS loads at St. Anthony Park subwatershed for baseflow, stormflow, and snowmelt from 2005-2013.
0
100,000
200,000
300,000
400,000
500,000
600,000
700,000
800,000
900,000
1,000,000
2005 2006 2007 2008 2009 2010 2011 2012 2013
TSS
Load
(lbs
)
Year
Snowmelt
Storm
Base
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 142
Figure 9-6: Monthly average storm sample TSS concentrations in 2013 for St. Anthony Park subwatershed and historical averages (2005-2012).
n=4
n=8
n=17
n=23
n=22
n=30
n=19
n=16
n=1n=
1
n=3
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200
400
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800
1,000
1,200
1,400
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
TSS
Con
cent
ratio
n (m
g/L)
Month
Historical Average (2005-2012)
2013
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 143
Figure 9-7: Historical and 2013 cumulative TSS yield from St. Anthony Park subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 144
Total Phosphorus (TP)
The TP load in 2013 (1,301 lbs) was not significantly different from previously monitored years (Figure 9-8); although it was the second highest load since full year monitoring began in 2009. The increase in the 2013 load is due in large part to the contribution of snowmelt. This snowmelt contribution, however, is calculated based on 4 samples taken 2012 and 2013 (2 each year). In future monitoring years, a greater effort will be made to sample snowmelt events and consistently report their contribution to discharge and loading. Stormflow and baseflow TP loads in 2013 were relatively consistent with 2009 to 2012. Monthly storm TP concentrations in 2013 were lower than the historical averages with the exception of August, which was significantly higher than the average (Figure 9-9). However, a low number of storm events were sampled in 2013 due to equipment issues. This resulted in the use of historical average concentrations for most storm intervals in 2013 when calculating loads, which could explain the minimal variation in TP load from previous monitoring years.
Figure 9-8: Historical total monitored TP loads at St. Anthony Park subwatershed for baseflow, stormflow, and snowmelt from 2005-2013.
0
500
1,000
1,500
2,000
2,500
2005 2006 2007 2008 2009 2010 2011 2012 2013
TP L
oad
(lbs)
Year
Snowmelt
Storm
Base
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 145
Figure 9-9: Monthly average storm sample TP concentrations in 2013 for St. Anthony Park subwatershed and historical averages (2005-2012).
n=4
n=8
n=17
n=23
n=22
n=30
n=19
n=16
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TP C
once
ntra
tion
(mg/
L)
Month
Historical Average (2005-2012)
2013
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 146
Figure 9-10: Historical and 2013 cumulative TP yield from St. Anthony Park subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 147
Total Nitrogen (TN)
At St. Anthony Park, stormflow and baseflow historically have contributed approximately equal shares of the overall total nitrogen yield. Historically, both the stormflow and baseflow TN yield increases have been constant over the course of the year with slight increases in mid to late September (Figure 9-11). In 2013, the May 18-20 storm events produced the majority of the TN yield (Figure 9-11), while reduced yield June through October resulted in a total yield significantly less than the historical average. The baseflow TN yield in 2013 was fairly consistent with the historical average, although there was an increase in yield mid-May to early June that deviated from the historical trend.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 148
Figure 9-11: Historical and 2013 cumulative TN yield from St. Anthony Park subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 149
Chloride (Cl-)
Historically at St. Anthony Park, the stormflow chloride yield represents a very small fraction of the total yield, with the majority coming from baseflow. Historical baseflow Cl- data at St. Anthony Park from January to March is not very robust and accounts for the abrupt jump in yield seen in Figure 9-12. During the normal period of snowmelt from March through April most CRWD sites show a large increase in Cl- yield. However, at St. Anthony Park there is not historically a significant increase. The 2013 Cl- yield showed a higher overall yield than the historical average, but continued the trend of not reflecting a large March to April increase. Because the St. Anthony Park monitoring site is located directly at the outfall to the Mississippi River, it is possible that river water backing up into the pipe is sufficient to dilute the storm sewer flow and result in samples with lower Cl- concentrations than are actually found further upstream in the storm sewer.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 150
Figure 9-12: Historical and 2013 cumulative Cl- yield from St. Anthony Park subwatershed for stormflow, baseflow, and combined baseflow + stormflow.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 151
9.3 2013 MONITORING SUMMARY - SARITA
Sarita has been monitored for flow and water quality since 2006. It is generally monitored from late March to mid-November. Sarita does not have baseflow, but may discharge for a prolonged period following large precipitation events. The number of monitoring days has not varied significantly year-to-year (Table 9-4). During the spring and early summer of 2013, various improvements were made to the Sarita wetland to increase its storage capacity and the residence time of water passing through it. Additionally, an access bridge was added to the outlet structure. Construction of this bridge took place mid-August to mid-September and disturbed the soil in the immediate vicinity of the outlet structure. Erosion control blankets and a floating silt curtain were used to reduce erosion and sediment transport into the storm sewer.
9.3.1 DISCHARGE
Discharge from the Sarita wetland in 2013 (16,792,317 cf) was higher than any previously monitored year. The number of storm intervals, monitoring days, and rainfall amount during the period monitored is similar to 2010-2012 (Figure 9-13; Table 9-4). The improvements to the wetland would be expected to result in reduced flow. However, in 2013, the majority of the yearly precipitation likely occurred before construction activities were completed. Figure 9-14 shows that the majority of the discharge occurred May through June, in which nearly 40% of the yearly precipitation occurred, while increases in water yield for the rest of the monitoring year followed the historical trend.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 152
Figure 9-13: Historical total monitored discharge volumes at Sarita for stormflow from 2006-2013.
Figure 9-14: Historical and 2013 cumulative water yield from Sarita for stormflow.
0
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
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7,000,000
8,000,000
9,000,000
2006 2007 2008 2009 2010 2011 2012 2013
Dis
char
ge (c
f)
Year
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St. Anthony Park
2013 CRWD Stormwater Monitoring Report 153
9.3.2 LOAD AND CONCENTRATION - SARITA
Total Suspended Solids (TSS)
The 2013 TSS load (63,090) was the highest on record (Figure 9-15; Table 9-4). The high suspended solids loads could be a result of construction activities in the wetland re-suspending sediment. The monthly concentration data (Figure 9-6) shows that May and June in particular had concentrations well above the historical average. This period in 2013 experienced the highest amount of rainfall, and if combined with wetland reconstruction, a significant amount of sediment could have been exported. Large storm events on May 18 (3.98 inches in 4 days) and June 21 (3.21 inches in 2 days) accounted for a combined 39% of the total TSS load. Figure 9-17 shows the large increase in yield resulting from the two events, far above the historical average for the site.
Figure 9-15: Historical total monitored TSS loads at Sarita for stormflow from 2006-2013.
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
2006 2007 2008 2009 2010 2011 2012 2013
TSS
Load
(lbs
)
Year
Storm
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 154
Figure 9-16: Monthly average storm sample TSS concentrations in 2013 for Sarita and historical averages (2006-2012).
n=1
n=4
n=8
n=13
n=16
n=19
n=11
n=12 n=
1
n=1
n=3
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n=3
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80
100
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180
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
TSS
Con
cent
ratio
n (m
g/L)
Month
Historical Average (2006-2012)
2013
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 155
Figure 9-17: Historical and 2013 cumulative TSS yield from Sarita for stormflow.
Total Phosphorus (TP)
The TP load in 2013 (190 lbs) was the highest on record (Figure 9-18; Table 9-4) for Sarita. The high TP load is likely related to the high TSS load. Therefore activities that affected sediment transport, also likely affected phosphorus export from the wetland. The monthly concentrations of TP were significantly higher than the historical average in May and June 2013. These high concentrations combined with high discharge resulted in the majority of the yearly TP yield occurring from May to June 2013 (Figure 9-20).
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 156
Figure 9-18: Historical total monitored TP loads at Sarita for stormflow from 2006-2013.
0
20
40
60
80
100
120
140
160
180
200
2006 2007 2008 2009 2010 2011 2012 2013
TP L
oad
(lbs)
Year
Storm
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 157
Figure 9-19: Monthly average storm sample TP concentrations in 2013 for Sarita and historical averages (2006-2012).
Figure 9-20: Historical and 2013 cumulative TP yield from Sarita for stormflow.
n=1
n=4
n=8
n=13
n=16
n=19
n=11
n=12
n=1
0.00
0
n=1
n=3
n=4
n=2
n=3
n=1
n=3
0.00
0
0.00
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0.35
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0.50
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
TP C
once
ntra
tion
(mg/
L)
Month
Historical Average (2006-2012)
2013
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 158
Total Nitrogen (TN)
The total nitrogen yield in 2013 from Sarita was significantly higher than the historical average (Figure 9-21). Like the TSS and TP yields, this was due in large part to two major events in May and June. The yield from August through October closely followed the historical trend of a slow consistent increase in yield.
Figure 9-21: Historical and 2013 cumulative TN yield from Sarita for stormflow.
Chloride (Cl-)
Historical chloride yields at Sarita follow a slightly different pattern than other District monitoring sites. At sites where baseflow is present year-round, the majority of the Cl- yield comes from this baseflow and not stormflow. Sarita only experiences stormflow and is not monitored for snowmelt volume, which may explain the different trends in Cl- yields. Increases in stormflow Cl- yield historically occur in late May and late July into early August (Figure 9-22). In 2013, major increases in Cl- yield occurred mid-May, late June, and late August, all of which deviated from the historical trend. The increases in May and June correspond to increases in other measured parameters resulting from large storm events. The increase in late August occurred during a relatively dry period of 2013. The Minnesota State Fair grounds are within the Sarita subwatershed, and the late August increase coincides with the dates of the State Fair. Therefore the increase in Cl- yield may have been caused by fair related activities. However, no similar increases are shown in the historical data during the State Fair time period.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 159
Figure 9-22: Historical and 2013 cumulative Cl- yield from Sarita for stormflow.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 160
Table 9-1: St. Anthony Park subwatershed monitoring results for 2005-2013.
2005 2006 2007 2008 2009 2010 2011 2012 2013Subwatershed Area (ac) 3,418 3,418 3,418 3,418 3,418 3,418 3,418 3,418 3,418Total Rainfall (inches) 28.27 24.13 23.99 9.95 18.72 26.84 29.24 29.71 34.00Number of Monitoring Days 191 192 215 126 218 188 269 334 351Number of Storm Sampling Events 44 21 19 12 25 17 7 5 8Number of Storm Intervals 9 23 33 24 38 44 17 30 30Number of Snowmelt Sampling Events NA NA NA NA NA NA 0 2 2Number of Snowmelt Intervals NA NA NA NA NA NA 0 3 24Number of Base Sampling Events 3 7 11 12 16 9 19 14 15Number of Baseflow Intervals 28 23 32 25 24 41 28 33 45Total Discharge (cf) 191,591,247 145,671,734 209,782,937 57,793,346 99,163,464 117,851,525 115,056,718 103,140,522 139,036,000Storm Flow Subtotal (cf) 65,769,117 49,091,775 60,484,181 19,865,767 41,313,601 57,480,844 26,284,149 37,566,038 30,798,646Snowmelt Subtotal (cf) NA NA NA NA NA NA 0 3,099,892 18,726,594Baseflow Subtotal (cf) 119,056,352 96,579,959 149,298,756 37,927,579 57,849,863 60,370,681 88,572,569 62,373,370 89,510,760Average TSS Concentration (mg/L) 124 108 145 129 138 149 89 75 102Total FWA TSS Concentration (mg/L) 66 62 72 92 95 123 73 63 93Storm FWA TSS Concentration (mg/L) 146 152 205 247 176 238 214 71 284Snowmelt FWA TSS Concentration (mg/L) NA NA NA NA NA NA 0 181 117Base FWA TSS Concentration (mg/L) 21 16 18 10 38 13 31 53 22Total TSS Loading (lbs) 787,976 564,202 941,282 330,829 589,228 904,150 524,922 408,192 804,368Storm TSS Loading (lbs) 599,259 465,259 774,686 306,571 453,744 853,968 353,893 165,371 546,783Snowmelt TSS Loading (lbs) NA NA NA NA NA NA 0 34,992 136,847Base TSS Loading (lbs) 153,661 98,943 166,595 24,258 135,484 50,182 171,030 206,376 120,738Total TSS Yield (lb/ac) 231 165 275 97 172 250 154 136 235Normalized Total TSS Yield (lb/ac/in runoff) 15 14 16 21 22 28 17 14 21Average TP Concentration (mg/L) 0.22 0.22 0.21 0.21 0.23 0.22 0.19 0.13 0.14Total FWA TP Concentration (mg/L) 0.17 0.14 0.13 0.16 0.17 0.18 0.13 0.13 0.15Storm FWA TP Concentration (mg/L) 0.23 0.27 0.27 0.33 0.29 0.30 0.26 0.19 0.30Snowmelt FWA TP Concentration (mg/L) NA NA NA NA NA NA 0.00 0.15 0.26Base FWA TP Concentration (mg/L) 0.14 0.08 0.07 0.07 0.09 0.06 0.09 0.10 0.08Total TP Loading (lbs) 1999 1,307 1,668 561 1,070 1,313 944 867 1,316Storm TP Loading (lbs) 942 820 1,031 406 738 1,091 431 440 571Snowmelt TP Loading (lbs) NA NA NA NA NA NA 0 30 302Base TP Loading (lbs) 1022 487 636 155 332 222 513 396 443Total TP Yield (lb/ac) 0.58 0.38 0.49 0.16 0.31 0.38 0.28 0.25 0.39Normalized Total TP Yield (lb/ac/in runoff) 0.04 0.03 0.03 0.04 0.04 0.04 0.03 0.03 0.03NA: Not available. Snow melt events w ere not monitored or sampled until 2011.
St. Anthony Park
2013 CRWD Stormwater Monitoring Report 161 Figure 9-23: 2013 St. Anthony Park level, velocity, and discharge.
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Note: Italics indicate estimated concentrations based on average historical monthly base, snowmelt and storm flow concentrations.
Trout Brook
2013 CRWD Stormwater Monitoring Report 173
10 TROUT BROOK SUBWATERSHED RESULTS
10.1 DESCRIPTION
The Trout Brook subwatershed is the largest subwatershed in CRWD, draining 8,000 acres in portions of St. Paul, Maplewood, Falcon Heights, and Roseville (Figure 10-4). The Trout Brook subwatershed contains Loeb Lake and five major stormwater ponds in St. Paul. Land use in the Trout Brook subwatershed is a mix of residential, industrial, and commercial, with 40% impervious surface. Runoff in the subwatershed drains to CRWD’s Trout Brook Storm Sewer Interceptor (TBI), which connects to the City of St. Paul’s storm sewer interceptor before eventually discharging to the Mississippi River, just downstream of Lambert’s Landing in St. Paul. The upper section of TBI is comprised of two branches, East and West, which converge near the intersection of Maryland Avenue and I-35E in St. Paul.
Trout Brook – West Branch
Trout Brook-West Branch (TB-WB) subwatershed drains 2,379 acres in St. Paul, Roseville, and Falcon Heights. It has the third largest drainage area of the full water quality monitoring sites. Within the boundaries of TB-WB are the Arlington-Jackson Stormwater Pond, Willow Reserve Stormwater Pond, Como Lake, Lake McCarrons, and Loeb Lake (Figure 10-4). However, it should be noted that the lakesheds of Como Lake and Lake McCarrons are not included in the total drainage area calculation for TB-WB because each lake behaves as its own subwatershed and do not consistently contribute runoff to the Trout Brook subwatershed. The TB-WB monitoring site is located just upstream of the convergence with the east branch of the TBI in the northwest quadrant of the intersection of Maryland Avenue and I-35E.
Figure 10-1: The Trout Brook-West Branch monitoring site location.
Trout Brook
2013 CRWD Stormwater Monitoring Report 174
Trout Brook – East Branch
Trout Brook-East Branch (TB-EB) subwatershed drains 932 acres in St. Paul and Maplewood and includes two stormwater ponds, Westminster-Mississippi and Arlington-Arkwright. First established in 2006, this monitoring station was moved slightly downstream in the pipe in 2007 from its original location to a manhole located between L’Orient Street and the I-35E ramp (Figure 10-4). The TB-EB subwatershed receives direct runoff from the I-35E corridor, which is very influential to the water quality measured at this monitoring station.
Figure 10-2: The Trout Brook-East Branch monitoring site location.
Trout Brook Outlet
The Trout Brook Outlet (TBO) monitoring station receives water from nearly 5,028 acres of the Trout Brook subwatershed, which includes the combined discharge from TB-EB and TB-WB monitoring locations. Like TB-WB, the TBO subwatershed does not include the lakeshed drainage areas of Como Lake and Lake McCarrons in its total drainage area (Figure 10-4)
Figure 10-3: The Trout Brook Outlet monitoring site location.
Trout Brook
2013 CRWD Stormwater Monitoring Report 175
Figure 10-4: Map of the Trout Brook subwatershed and monitoring locations.
The TB-WB subwatershed has been monitored by CRWD for discharge and water quality from 2005 to 2013. Flow monitoring at the TB-WB monitoring location is currently continuous, though year-round flow monitoring did not begin until 2010. Prior to 2010, flow was recorded between the months of April to November. Over time, flow monitoring at TB-WB has shown a unique relationship between stage and velocity during storm events. Once water level reaches a stage threshold of approximately 0.4 ft, velocity begins to drastically decrease to show an inverse relationship between stage and velocity. CRWD staff has attributed this unique discharge relationship to the close proximity of the TB-WB monitoring station to the confluence of the TB-WB and TB-EB tunnels. It is hypothesized that when incoming flow from TB-WB reaches the confluence, it flows into TB-EB discharge nearly perpendicularly, which causes turbulence and backflow of water into the TB-WB pipe. Therefore, though the water is recorded at a high stage in TB-WB, the flow velocity is recorded as low because the water has been slowed and backed up.
10.2.1 DISCHARGE
The annual discharge from TB-WB (344,928,332 cf) in 2013 was the highest total volume recorded at this site since year-round monitoring began in 2010 (Figure 10-5; Table 10-2). In 2013, baseflow (231,825,518 cf) comprised the majority of the total flow (67%) and stormflow (82,367,885 cf) only accounted for 24% of the total flow. Snowmelt was also a significant contributor, equaling 9% (30,734,929 cf) of total annual flow in 2013. Increases in total discharge in 2013 in comparison to the historical monitoring record can be directly related to increases in total annual precipitation (5.75 in above the 30-year normal) and a deep winter snowpack that melted slowly. The stormflow cumulative water yield (Figure 10-6) in 2013 greatly increased at TB-WB following a few significant storm events in May and June 2013. Because of these large events, the 2013 stormflow cumulative water yield trend varied from the historical average (2005-2012). The 2013 baseflow cumulative water yield also varied from the historical average (2005-2012) at TB-WB (Figure 10-6). Baseflow water yield steadily increased at a relatively constant rate throughout the entire year, though the rate of baseflow yield increased in May and June which was likely in response to the large rainfall inputs. For combined storm and baseflow cumulative water yield, the trend line closely follows the increases shown in stormflow yield with rate increases in May and June 2013 Figure 10-6). Also, the combined cumulative water yield varied from the historical mean (2005-2012).
Trout Brook
2013 CRWD Stormwater Monitoring Report 177
Figure 10-5: Historical total monitored discharge volumes at Trout Brook-West Branch for baseflow, stormflow, and snowmelt from 2005-2013.
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2013 CRWD Stormwater Monitoring Report 178
Figure 10-6: Historical and 2013 cumulative water yield from Trout Brook-West Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 179
10.2.2 LOAD AND CONCENTRATION
Total Suspended Solids (TSS)
For TB-WB, the 2013 total TSS load (1,697,137 lbs) for the entire year was the second largest amount since monitoring began in 2005, only exceeded by the 2010 TSS total load of 1,991,582 (Figure 10-7; Table 10-2). TSS loading at TB-WB was primarily a result of storm events (76% of total load). Approximately 17% of TSS loading occurred during baseflow periods (though baseflow was 67% of total flow) and 7% occurred during snowmelt periods. For average monthly TSS storm concentrations (Figure 10-8), the highest monthly average concentrations were observed in August (778 mg/L) and September 2013 (1,090 mg/L), which was unexpected because these months had the driest precipitation period of the year. Also, these values were significantly higher than any historical TSS average concentration ever observed at TB-WB by a substantial amount.
Figure 10-7: Historical total monitored TSS loads at Trout Brook-West Branch for baseflow, stormflow, and snowmelt from 2005-2013.
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Trout Brook
2013 CRWD Stormwater Monitoring Report 180
Figure 10-8: Monthly average storm sample TSS concentrations in 2013 for Trout Brook-West Branch and historical averages (2007-2012).
The stormflow cumulative TSS yields at TB-WB were more strongly influenced by precipitation events (Figure 10-9). Large increases in TSS yield occurred in May and June 2013 due to the significant amount of precipitation that occurred during that time period (Figure 10-9). Alternatively, the 2013 baseflow cumulative TSS yield greatly increased in August and September 2013 during the extended dry period. Prior to that time, TSS yields from baseflow occurred at a relatively constant rate from April to August. In general, the baseflow cumulative TSS yield was substantially less than the stormflow yield; thus, TSS loading is primarily driven by stormflow at TB-WB. Overall, combined stormflow and baseflow cumulative TSS yield for 2013 varied from the historical mean (2005-2012), but generally followed a similar seasonal trend (Figure 10-9). This is also likely due to the above average precipitation year.
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Trout Brook
2013 CRWD Stormwater Monitoring Report 181
Figure 10-9: Historical and 2013 cumulative TSS yield from Trout Brook-West Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 182
Total Phosphorus (TP)
The 2013 total TP load (4,134 lbs) for the entire year was the largest total annual load recorded at TB-WB (Figure 10-10; Table 10-2). Storm events accounted for 52% (2,159 lbs) of the annual TP loading and snowmelt contributed 12% (478 lbs). Baseflow TP loading contributed 36% (1,497 lbs) of the annual TP load, which was the greatest annual baseflow TP load ever recorded at TB-WB since monitoring began in 2005 (Figure 10-10; Table 10-2 ). Starting in 2010 when continuous year-round monitoring began at TB-WB, baseflow TP loading has steadily increased over time. Similar to TSS, average monthly TP storm concentrations at TB-WB were greatest in August (0.732 mg/L) and September 2013 (0.640 mg/L) (Figure 10-11). These concentration values were also unexpected because August and September 2013 were the driest period of the year. Both values greatly exceeded the historical monthly average concentrations while none of the other 2013 months did (including May and June 2013 which had high precipitation).
Figure 10-10: Historical total monitored TP loads at Trout Brook-West Branch for baseflow, stormflow, and snowmelt from 2005-2013.
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Trout Brook
2013 CRWD Stormwater Monitoring Report 183
Figure 10-11: Monthly average storm sample TP concentrations in 2013 for Trout Brook-West Branch and historical averages (2007-2012).
Stormflow TP yields in 2013 at TB-WB closely mimicked precipitation trends with increases in TP following large precipitation events in May and June 2013 (Figure 10-12). For baseflow, cumulative TP yields increased steadily from April 2013 until mid-August when a large increase occurred (Figure 10-12). Following September 2013, baseflow TP yields resumed a normal steady trend. Overall, the combined stormflow and baseflow TP yield for 2013 was similar in accumulation to the historical mean (2005-2012), though large increases in TP were driven by precipitation trends (Figure 10-12). TP loading is primarily driven by stormflow at TB-WB; the baseflow cumulative TP yield is much less than the stormflow yield.
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2013 CRWD Stormwater Monitoring Report 184
Figure 10-12: Historical and 2013 cumulative TP yield from Trout Brook-West Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 185
Total Nitrogen (TN)
The stormflow TN yield trends for 2013 at TB-WB closely followed water yield trends (Figure 10-13). Substantial increases in TN yields occurred in May and June 2013 during large precipitation events and then plateaued in July through November during drier months. The baseflow cumulative TN yield trends were relatively steady from April to November 2013 (Figure 10-13). The 2013 TN yield was much greater than the historical mean (2005-2012). Baseflow TN loading is overall greater than stormflow TN loading at TB-WB. Overall, the 2013 combined stormflow and baseflow TN yield for 2013 varied from the historical mean (Figure 10-13). Initially, the 2013 TN yield was similar to the historical mean from April to mid-May, but following the large precipitation events in May and June, the 2013 combined cumulative TN load substantially increased and deviated from the historical mean.
Trout Brook
2013 CRWD Stormwater Monitoring Report 186
Figure 10-13: Historical and 2013 cumulative TN yield from Trout Brook-West Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 187
Chloride (Cl-)
For Cl-, stormflow cumulative yields at TB-WB increased from the beginning of April 2013, likely due to snowmelt and road salt runoff from the winter months (Figure 10-14). The large precipitation events in May and June 2013 sharply increased the stormflow Cl- yields, but following June, Cl- loading plateaued for the remainder of the year. Overall, 2013 stormflow cumulative Cl- yields were greater than the historical mean. The total baseflow Cl- yield (725 lb/ac) was substantially greater than the total stormflow yield (63 lb/ac) in 2013. The trend of baseflow Cl- yielding increased substantially from March to April 2013 (Figure 10-14). Rates of baseflow Cl- yield increases slowed by mid-July through November. Overall, the combined baseflow and stormflow total Cl- yield for 2013 was significantly greater than the historical mean. However, the trend line showing the seasonal rate of accumulation is similar to the historic means (Figure 10-14).
Trout Brook
2013 CRWD Stormwater Monitoring Report 188
Figure 10-14: Historical and 2013 cumulative Cl- yield from Trout Brook-West Branch for stormflow, baseflow, and combined baseflow + stormflow.
The TB-EB subwatershed has been monitored by CRWD for discharge and water quality from 2006-2013. Since 2010, flow monitoring at TB-EB has been continuous and year-round. Prior to 2010, flow was recorded between the months of April to November. In 2007, the TB-EB monitoring station was moved downstream from its original location to its current location. The TB-EB monitoring station is adjacent to I-35E and just downstream of a ditch that collects runoff from the highly impervious highway corridor. Subsequently, monitoring at TB-EB has shown a very short lag-to-peak response time during precipitation events. Data shows that these flashy flows from TB-EB directly affect the discharge of water from the TB-WB tunnel. Water from TB-WB and TB-EB meet nearly perpendicularly to one another. During a large storm event, TB-EB’s high velocity flow can dominate the channel and force TB-WB to back up.
10.3.1 DISCHARGE
In 2013, total discharge from TB-EB (49,693,121 cf) was the highest volume of discharge exported by the TB-EB subwatershed since continuous monitoring began in 2010 (Figure 10-15; Table 10-5). Baseflow (25,955,622 cf) in 2013 accounted for 52% of the total flow while stormflow (16,230,742 cf) comprised 33% of the total (Figure 10-15). Snowmelt was also a significant contributor, especially in comparison to previous years, comprising 15% (7,466,757 cf) of the total annual flow. Increases in baseflow, stormflow, and snowmelt at TB-EB in 2013 can all be attributed to an above average precipitation year with a deep winter snowpack that melted slowly into April. The 2013 stormflow cumulative water yield at TB-EB (Figure 10-16) greatly increased following a few significant storm events in May and June 2013. Because of these large events, the 2013 stormflow cumulative water yield was significantly greater than the historical mean (2006-2012). For TB-EB, the 2013 baseflow cumulative water yield was also significantly higher than the historical mean (2006-2012). The trend in water yield started off similar to the mean in April 2013 (Figure 10-16). By mid-May 2013, baseflow water yield began deviating from the historical mean, likely because a substantial amount of groundwater recharge occurred following the snowmelt period. Overall, baseflow water yield steadily increased at a relatively constant rate, slightly higher than the average, throughout the entire year. The combined storm and baseflow cumulative water yield at TB-EB, closely followed the increases shown in stormflow yield with sharp increases in May and June 2013 (Figure 10-16). The water yield increase September to November was very similar to the historical average for the site during that time period.
Trout Brook
2013 CRWD Stormwater Monitoring Report 190
Figure 10-15: Historical total monitored discharge volumes at Trout Brook-East Branch for baseflow, stormflow, and snowmelt from 2006-2013.
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2013 CRWD Stormwater Monitoring Report 191
Figure 10-16: Historical and 2013 cumulative water yield from Trout Brook-East Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 192
10.3.2 LOAD AND CONCENTRATION
Total Suspended Solids (TSS)
In 2013, the total annual TSS load from TB-EB (380,532 lbs) was over 2.5 times greater than the previous highest amount in the historical monitoring record occurring in 2012 with a load of 143,168 lbs (Figure 10-17). The total storm TSS load (336,596 lbs) was substantial and accounted for 88% of the total annual load. The total snowmelt TSS loads (14,872 lbs) and baseflow TSS loads (29,064) were less significant contributors to the total annual load. A major contributing factor to the extremely high storm TSS load was construction that occurred in the I-35E corridor adjacent to the monitoring station in summer 2013. Large rain events June 20-22 and August 28-29, 2013 washed a large amount of the construction sediment into the TB-EB storm sewer (combined 37% of the total load). The highest monthly average TSS concentrations at TB-EB were observed in August 2013 (1,538 mg/L) and September 2013 (671 mg/L). Both months represent periods of nearby construction. For every month in 2013, average TSS concentrations greatly exceeded the historical averages, except for April, in which only one sample was taken (Figure 10-18).
Figure 10-17: Historical total monitored TSS loads at Trout Brook-East Branch for baseflow, stormflow, and snowmelt from 2006-2013.
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2013 CRWD Stormwater Monitoring Report 193
Figure 10-18: Monthly average storm sample TSS concentrations in 2013 for Trout Brook-East Branch and historical averages (2007-2012).
The TB-EB stormflow cumulative TSS yield was most strongly influenced by stormflow events (instead of average monthly concentrations) (Figure 10-19). The greatest increase in yield occurred mid-June 2013 following the June 21 precipitation event. Stormflow TSS yield increased at a lower rate as precipitation decreased in August and September 2013, though still higher than the historical average (Figure 10-19). TSS loading from baseflow occurred at a relatively constant rate, greater than the historical average, from May to November. In contrast to other district sites, the 2013 TB-EB baseflow cumulative TSS yield showed a marked increase in August and September 2013 during the extended dry period (Figure 10-19). Baseflow TSS yields at TB-EB were substantially less than stormflow yields highlighting that the TSS load is primarily driven by stormflow. The TB-EB combined stormflow and baseflow cumulative TSS yield for 2013 was significantly greater than the historical mean (2005-2012) (Figure 10-19). This is also likely due to the higher than average precipitation year. The biggest increases in TSS yields were apparent in June 2013 (related to stormflow) and August 2013 (related to construction activity).
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2013 CRWD Stormwater Monitoring Report 194
Figure 10-19: Historical and 2013 cumulative TSS yield from Trout Brook-East Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 195
Total Phosphorus (TP)
For TB-EB, the 2013 total TP load (804 lbs) was the greatest total annual load ever observed since year-round monitoring began in 2010 (Figure 10-20; Table 10-5). Storm events accounted for 60% (480 lbs) of the annual TP load. Snowmelt was also a significant contributor to the TP load in 2013 (17% or 136 lbs). Baseflow accounted for a greater fraction of the total load than all previously monitored years. Average monthly TP storm concentrations at TB-EB were greatest in August (0.745 mg/L) and September 2013 (0.798 mg/L) (Figure 10-21). These concentration values were unusual because August and September 2013 were the driest period of the year, but it is possible they are related to nearby construction activities that were occurring during that time. Both values greatly exceeded the historical monthly average concentrations as did the average TP concentrations in May, June, and October 2013.
Figure 10-20: Historical total monitored TP loads at Trout Brook-East Branch for baseflow, stormflow, and snowmelt from 2006-2013.
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2013 CRWD Stormwater Monitoring Report 196
Figure 10-21: Monthly average storm sample TP concentrations in 2013 for Trout Brook-East Branch and historical averages (2007-2012).
A sharp increase in stormflow TP yield was observed following the May 17-20 and June 20-22
events (Figure 10-22). Prior to that, the 2013 TP yield followed the historical stormflow mean. When precipitation declined in August and September 2013, stormflow TP yield rate returned to approximately the historical average rate. Baseflow cumulative TP yields at TB-EB increased steadily throughout the year and at a greater rate than the historical mean starting in mid-May 2013 (Figure 10-22). Overall, baseflow TP yields were much lower than stormflow yields, showing that TP loads are primarily driven by stormflow at TB-EB. Overall, the 2013 combined stormflow and baseflow cumulative TP yield at TB-EB was greater than the historical mean and increases closely followed the stormflow water yield trends (Figure 10-22).
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2013 CRWD Stormwater Monitoring Report 197
Figure 10-22: Historical and 2013 cumulative TP yield from Trout Brook-East Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 198
Total Nitrogen (TN)
For TB-EB, the trends for 2013 cumulative stormflow TN yields were similar to the water yield trends (Figure 10-23). Substantial increases in TN yield occurred mid-May and mid-June 2013 during large precipitation events. The TN yield increase July through November, during drier months, approached the historical trend. The baseflow yield for TN increased relatively steadily from April to November 2013 with a slight increase in June 2013 (Figure 10-23). The 2013 TN yield started off similar to the historical mean, but exceeded the average in May 2013. Overall, the 2013 TB-EB combined stormflow and baseflow cumulative TN yield for 2013 was greater than the historical mean (Figure 10-23). During the beginning of the monitoring season, the 2013 TN yield was similar to the historical mean from April to mid-May, but following a wet spring with large precipitation events in May and June, the 2013 combined cumulative TN yield substantially increased above the historical mean. Stormflow cumulative TN yields were greater than baseflow yields and the combined cumulative yield trends closely followed stormflow; thus TN loading is primarily driven by stormflow at TB-EB.
Chloride (Cl-)
Starting April 1, 2013, the stormflow cumulative Cl- loading yields at TB-EB were greater than the historical mean (Figure 10-24). The large precipitation events in May and June 2013 also sharply increased the stormflow Cl- yields. Following June 2013, stormflow Cl- yield increased at a rate lower than the average for the remainder of the year. Baseflow Cl- yields comprise significantly more of the total yield than stormflow. The cumulative Cl- yield for baseflow increased drastically above the mean in March to April 2013 (Figure 10-24) during an extended period of snowmelt. Following April 2013, the baseflow Cl- yield increased at a constant rate greater than the historical mean for the remainder of the year.
Trout Brook
2013 CRWD Stormwater Monitoring Report 199
Figure 10-23: Historical and 2013 cumulative TN yield from Trout Brook-East Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 200
Figure 10-24: Historical and 2013 cumulative Cl- yield from Trout Brook-East Branch for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
2013 CRWD Stormwater Monitoring Report 201
10.4 2013 MONITORING SUMMARY – TROUT BROOK OUTLET
The Trout Brook Outlet (TBO) subwatershed has been monitored by CRWD for discharge and water quality from 2005 to 2013. Year-round continuous flow monitoring at TBO began in 2010. From 2005-2009, flow was only recorded during the months of April to November. The TBO monitoring station is located downstream of both TB-WB and TB-EB and less than a mile upstream of the Trout Brook Interceptor outfall to the Mississippi River. Discharge and water quality recorded at this station is nearly representative of the entire Trout Brook subwatershed, which has the largest drainage area of all CRWD subwatersheds.
10.4.1 DISCHARGE
In 2013, total discharge from TBO (536,193,654 cf) was the greatest volume of discharge exported by the TBO subwatershed since monitoring began in 2005 (Figure 10-25; Table 10-8). The 2013 TBO baseflow (410,556,091 cf) comprised the majority of the total flow (77%). Stormflow (91,385,535 cf) only accounted for 17% of the total flow and snowmelt (33,744,420 cf) was 6%. Overall increases in baseflow, and snowmelt at TBO in 2013 can likely be attributed to the above average precipitation year and the deep winter snowpack that melted slowly into April. The 2013 stormflow cumulative water yield at TBO greatly increased following a few significant storm events in May and June 2013. However, the 2013 stormflow water yield increased at a rate less than the historical mean (2005-2012) for much of the year. In particular, stormflow water yield significantly tapered off in July 2013. This trend can be attributed to fewer precipitation events after July. The 2013 baseflow cumulative water yield at TBO increased at a rate close to the historical average until mid-August when baseflow water yield continued to steadily increase deviating from the mean (Figure 10-26). Beginning in late July, groundwater was pumped into the Trout Brook Interceptor upstream of TBO as part of a major construction project and lasted until the end of October. This water added to the baseflow volume monitored at TBO. Overall, baseflow water yield steadily increased at a relatively constant rate throughout the entire year. The combined storm and baseflow cumulative water yield at TBO closely followed baseflow trend showing that water yield at TBO is primarily driven by baseflow (Figure 10-26). Overall, the combined cumulative water yield was greater than the historical mean (2005-2012), but not by a substantial amount.
Trout Brook
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Figure 10-25: Historical total monitored discharge volumes at Trout Brook Outlet for baseflow, stormflow, and snowmelt from 2005-2013.
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Figure 10-26: Historical and 2013 cumulative water yield from Trout Brook Outlet for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
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10.4.2 LOAD AND CONCENTRATION
Total Suspended Solids (TSS)
The total annual TSS load from TBO (2,164,883 cf) was the third highest amount in comparison to the historical monitoring record (2005-2012) (Figure 10-27; Table 10-8). TSS loading from storm events (1,608,203 lbs) accounted for the majority (74%) of the total annual load. Snowmelt TSS loading (182,492 lbs) was greater than previous years and comprised 8% of the total load. The total baseflow TSS load (372,953 lbs) was less significant than stormflow, but was the highest baseflow load since continuous monitoring began in 2010. For TBO average monthly TSS storm concentrations (Figure 10-28), the highest monthly average concentration was observed in May (419 mg/L) and July, 2013 (884 mg/L). The high average TSS concentration in July 2013 is due to only two samples collected and one sample that was collected during a significant storm event while construction activities were occurring upstream of TBO. In comparison to historical average monthly TSS concentrations, all months in 2013 exceeded the average except for April, September, and October 2013.
Figure 10-27: Historical total monitored TSS loads at Trout Brook Outlet for baseflow, stormflow, and snowmelt from 2005-2013.
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Figure 10-28: Monthly average storm sample TSS concentrations in 2013 for Trout Brook Outlet and historical averages (2007-2012).
The 2013 cumulative TSS yield for stormflow at TBO increased significantly mid-May and mid-June, 2013 following large storm events (Figure 10-29). The lack of precipitation from July through September 2013 caused cumulative TSS yield for stormflow to increase at a rate significantly less than the historical average for the time of year. The 2013 baseflow cumulative TSS yield at TBO increased at a rate greater than the historical mean starting in mid-June (Figure 10-29). The higher than average rate July to October is likely due to construction related groundwater pumping upstream of TBO. Starting mid-October 2013, a sharp increase in baseflow TSS yield was observed at TBO. While no direct conclusions can be made to identify the source of this increase, it could potentially be related to upstream construction activities or autumn leaf-off. The combined cumulative TSS yield for TBO increased above the historical average following major storm events and returned to a rate close to the average September to November. The 2013 trends in combined TSS yield closely followed the trends in stormflow water yield.
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Figure 10-29: Historical and 2013 cumulative TSS yield from Trout Brook Outlet for stormflow, baseflow, and combined baseflow + stormflow.
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Total Phosphorus (TP)
The 2013 total annual TP load (5,078 lbs) at TBO was the second highest recorded at this monitoring station in comparison to the historical record (2005-2012) (Figure 10-30; Table 10-8). Total stormflow TP loading (2,762 lbs) was the majority of the total annual load (54%). Total baseflow TP load (1,650 lbs) was also significant, contributing 33% of the total load and was the highest baseflow load since 2006. Snowmelt was also a significant contributor to the 2013 TP load (661 lbs). The greatest monthly average TP concentration was observed in July 2013 (0.834 mg/L), which was over two-times higher than the historical average for July (0.372 mg/L). However, the 2013 July average concentration is based on only two samples. All months in 2013 (except April and October) exceeded monthly average storm TP concentrations at TBO.
Figure 10-30: Historical total monitored TP loads at Trout Brook Outlet for baseflow, stormflow, and snowmelt from 2005-2013.
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Figure 10-31: Monthly average storm sample TP concentrations in 2013 for Trout Brook Outlet and historical averages (2007-2012).
The stormflow cumulative TP yield at TBO in 2013 increased at a lower rate than the historical average April to mid-May, increased significantly due to large events mid-May and mid-June and then dropped below the average rate July to mid-September during a very dry period. The baseflow cumulative TP yield and TBO in 2013 steadily increased throughout the year and began exceeding the historical average rate beginning in June 2013 (Figure 10-32). From July onward, the 2013 TSS yield continued to increase steadily deviating significantly from the historical average. This is likely due to groundwater pumping into the Trout Brook Interceptor associated with construction from July to October. For combined cumulative TP yield, the 2013 trend line closely follows that of the historical mean (2005-2012) with the exception of decreases in rate from April to mid-May and mid-June to mid-August (Figure 10-32). Major changes in the trend line can be directly related to significant precipitation events in 2013 indicating stormflow is the primary driver of TP yields at TBO.
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Figure 10-32: Historical and 2013 cumulative TP yield from Trout Brook Outlet for stormflow, baseflow, and combined baseflow + stormflow.
Trout Brook
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Total Nitrogen (TN)
The stormflow cumulative TN yield at TBO in 2013 greatly increased in May and June following large precipitation events and then yield increases slowed beginning in July when precipitation decreased. Because baseflow comprises the majority of the discharge at TBO, the total baseflow cumulative TN yield was much greater than the total stormflow yield at TBO. The rate of baseflow TN yield increase was close to the historical value until May when it began to deviate slightly and continued to increase steadily for the remainder of the year. The combined baseflow and stormflow cumulative yield throughout the year was similar to the historical mean (Figure 10-33). Since TN loading is primarily driven by baseflow, the combined cumulative TN yield trend line was very similar to the baseflow trend line.
Chloride (Cl-)
The stormflow cumulative Cl- yield at TBO generally increased at a lower rate than the historical mean in 2013 (Figure 10-34). Large increases in Cl- loading were observed in April, May and June 2013. Stormflow Cl- yield generally slowed as precipitation events decreased in late summer to fall, 2013. Because the baseflow Cl- yield at TBO was substantially greater than the stormflow yield (Figure 10-34), the combined Cl- yield did not strongly reflect the influence of the trends in stormflow yield. The 2013 cumulative Cl- yield closely followed the historical average for the site (Figure 10-34).
Trout Brook
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Figure 10-33: Historical and 2013 cumulative TN yield from Trout Brook Outlet for stormflow, baseflow, and combined baseflow + stormflow.
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Figure 10-34: Historical and 2013 cumulative Cl- yield from Trout Brook Outlet for stormflow, baseflow, and combined baseflow + stormflow.
The Trout Brook Subwatershed has four stormwater ponds that are monitored by CRWD: (1) Arlington-Jackson, (2) Westminster-Mississippi, (3) Willow Reserve, and (4) Sims-Agate. Each site has been monitored since 2006 using a Global Water level logger. The water level data from these stormwater ponds is used to calibrate hydrologic and hydraulic models for the Trout Brook Interceptor. The stormwater ponds are generally monitored from April to November (or, ice-out to ice-in). In 2013, the average water level in each stormwater pond was similar to previous monitoring years in the historical record (Table 10-1). However, each pond fluctuated in level throughout the year depending on annual precipitation trends (Figure 10-41, Figure 10-42, Figure 10-43, and Figure 10-44). All four of the stormwater ponds peaked in level following the June 21, 2013 event and then decreased in level into July, August, and September 2013 throughout the extended dry period. Sims-Agate shows particularly interesting level data with major fluctuations in August and September 2013, which can be attributed to construction activities during that time (a stop-block was installed in front of the weir to hold back water).
Table 10-1: Historic monitoring record (2006-2013) of average annual stormwater pond levels in the Trout Brook subwatershed.
Actual number less than value (<)Actual number greater than value (>)Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit.
Actual number less than value (<)Actual number greater than value (>)Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit.
Storm 0.45 214 10/17/2013 20:30 10/18/2013 09:00 1,716,850 48.06 22,965 Base Composite 10/23/2013 11:17 10/24/2013 05:16 0.08 47 10/18/2013 09:15 11/04/2013 12:15 23,967,700 125.68 70,322 Storm 0.43 163 11/04/2013 12:30 11/06/2013 23:00 4,305,120 116.77 43,672 Base Composite 11/07/2013 11:47 11/08/2013 10:01 0.08 14 11/04/2013 23:15 12/02/2013 23:45 34,667,144 177.46 30,298 Base Grab 12/12/2013 12:30 12/12/2013 12:30 0.07 10 12/03/2013 00:00 12/31/2013 23:45 36,539,000 150.55 22,810 Snowmelt Flow-Weighted Average 0.31 87 Snowmelt Subtotal 33,744,420 661 182,492 Storm Flow-Weighted Average 0.48 282 Storm Subtotal 91,385,535 2,762 1,608,203 Illicit Discharge-Weighted Average 0.16 39 Illicit Discharge Subtotal 507,608 5 1,236 Base Flow-Weighted Average 0.06 15 Base Subtotal 410,556,091 1,650 372,953 Total Flow-Weighted Average 0.15 65 Total 536,193,654 5,077 2,164,883
Note: Italics indicate estimated concentrations based on average historical monthly base, snowmelt and storm flow concentrations.
Trout Brook
2013 CRWD Stormwater Monitoring Report 235
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Figure 10-41: 2013 Arlington-Jackson elevation and precipitation.
Trout Brook
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Figure 10-42: 2013 Sims-Agate elevation and precipitation.
Trout Brook
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Figure 10-43: 2013 Westminster-Mississippi elevation and precipitation.
Trout Brook
2013 CRWD Stormwater Monitoring Report 238
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Figure 10-44: 2013 Willow Reserve elevation and precipitation.
Lake McCarrons
2013 CRWD Stormwater Monitoring Report 239
11 LAKE MCCARRONS SUBWATERSHED RESULTS
11.1 DESCRIPTION
The Lake McCarrons subwatershed drains 1,070 acres and is the northernmost subwatershed in CRWD, located entirely within the city limits of Roseville (Figure 11-2). Land use in the subwatershed is predominantly residential and parkland. As a result, the percentage of impervious surfaces in the Lake McCarrons subwatershed is less than the other subwatersheds monitored by CRWD. More than half of the Lake McCarrons subwatershed (753 acres) flows through the Villa Park Wetland System which is designed to capture stormwater and provide treatment before discharging water to the lake. CRWD operates a monitoring station at the outlet of the Villa Park Wetland System (called Villa Park Outlet) in order to quantify and characterize the water exiting the wetland system to Lake McCarrons. CRWD also operates a flow-only station at the outlet of Lake McCarrons (called McCarrons Outlet) to determine total discharge from the lake during storm events (the lake only discharges when water levels are higher than normal). When it overflows, water flowing from the outlet of Lake McCarrons enters the Trout Brook Storm Sewer System which eventually discharges to the Mississippi River. For more information on the water quality of Lake McCarrons, refer to the 2013 CRWD Lakes Monitoring Report.
Figure 11-1: The Lake McCarrons Outlet monitoring site location (left); and Villa Park Wetland System (Villa Park Outlet) monitoring site location (right).
Lake McCarrons
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Lake McCarrons
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11.2 2013 MONITORING SUMMARY - VILLA PARK OUTLET
The Lake McCarrons subwatershed has been monitored for discharge and water quality at the Villa Park Outlet from 2006-2013. Flow and water quality monitoring at this location generally occurs between the months of April to November. During the winter months, baseflow grab samples are taken once a month, but level or flow are not recorded during this period. In 2013, the Villa Park Wetland System underwent a major dredging project aimed at increasing pond depth and water residence time in order to improve the quality of water discharging from the Villa Wetland into Lake McCarrons. Dredging activities began in June 2013 and ended in August 2013. Consequently, the annual flow data and pollutant loading from Villa Park Outlet may appear different than previous monitoring years because a stop block was installed in front of the outlet weir to prevent water that was disturbed from the dredging activities from flowing out of the Villa Wetland into Lake McCarrons.
11.2.1 DISCHARGE
In 2013, total discharge from Villa Park Outlet (16,792,317 cf) was the highest volume ever recorded at this site during the monitoring season (April-November) since monitoring began in 2006 (Figure 11-3; Table 11-2). In 2013, stormflow (12,633,927 cf) accounted for 75% of the total discharge at Villa Park Outlet. The 2013 baseflow (4,158,390 cf) accounted for 25%, which was greater than the 2006-2012 historical baseflow average (3,689,391 cf). The increase in stormflow at Villa Park Outlet in 2013 can likely be attributed to observed increases in total annual precipitation (5.75 in above the 30-year normal). In addition, dredging activities may have altered the timing of flow exiting the wetland due to water build up behind the stop block followed by a rapid release of it through the channel. For 2013 stormflow cumulative water yield (Figure 11-4), a sharp increase in water yield occurred from storm events in May and June 2013 surmounting in a high intensity event on June 21 (1.13 inches in 15 minutes). As precipitation decreased in July and August, the trend in water yield flattened until a large event occurred again on October 2. The 2013 cumulative baseflow water yield trend was different than the historical baseflow mean (2006-2012) at Villa Outlet (Figure 11-4). More significant increases in baseflow yields generally occurred from the end of June to mid-August, which was during the dredging project time period. Since Villa Park Outlet is primarily driven by stormflow, the combined storm and baseflow cumulative water yield trend closely follows the stormflow only trend line in Figure 11-4. Similarly to stormflow only, the 2013 combined cumulative water yield varied from than the historical mean (2006-2012) due to significant precipitation events in May and June 2013 (Figure 11-4).
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Figure 11-3: Historical total monitored discharge volumes at Villa Park Outlet for baseflow and stormflow from 2006-2013.
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Figure 11-4: Historical and 2013 cumulative water yield from Villa Park Outlet for stormflow, baseflow, and combined baseflow + stormflow.
Lake McCarrons
2013 CRWD Stormwater Monitoring Report 244
11.2.2 LOAD AND CONCENTRATION
Total Suspended Solids (TSS)
In 2013, the total TSS load from Villa Park Outlet (52,906 lbs) from April to October was the second largest amount since monitoring began in 2006, only exceeded by the 2010 TSS load (64,362 lbs) (Figure 11-5; Table 11-2). The TSS loading at Villa Park Outlet primarily occurred during storm events (88% of total TSS load). Total baseflow TSS loading (6,599 lbs) was only 12% of the total load. Increases in TSS loading at Villa Park Outlet in 2013 are likely related to increases in annual precipitation (particularly in May and June) as well as dredging activities. In evaluating 2013 average monthly TSS storm concentrations at Villa Park Outlet, the highest concentrations were observed in June (71.75 mg/L) and July 2013 (49.0 mg/L), both of which exceeded the historical (2006-2012) average monthly TSS storm concentrations for those months (Figure 11-6). June, July, and September 2013 exceeded the historical average monthly TSS storm concentrations, while all other months during the monitoring period had average monthly TSS storm concentrations below the historical averages. Historically, March, August, and October have the highest average monthly storm TSS concentrations.
Lake McCarrons
2013 CRWD Stormwater Monitoring Report 245
Figure 11-5: Historical total monitored TSS loads at Villa Park Outlet for baseflow and stormflow from 2006-2013.
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2013 CRWD Stormwater Monitoring Report 246
Figure 11-6: Monthly average storm sample TSS concentrations in 2013 for Villa Park Outlet and historical averages (2006-2012).
Similar to the stormflow cumulative water yield results in Figure 11-4, the 2013 stormflow cumulative TSS yield increased dramatically in mid-May and mid-June 2013 due to the significant amount of precipitation that occurred during that time period (Figure 11-7). Storm TSS yield trends plateaued in August through September due to the extended dry period during those months. The 2013 cumulative baseflow TSS yield in Figure 11-7 is similar to the trend shown by baseflow cumulative water yield in Figure 11-4. However, there was a significant springtime increase in baseflow TSS yield during the beginning of May 2013. This could potentially be attributed to ice out on the ponds and suspension of organic matter that decomposed over the winter months. Overall, the 2013 combined stormflow and baseflow cumulative TSS yield for 2013 was significantly greater than the historical average (2006-2012) (Figure 11-7). This is also likely due to higher than average precipitation year.
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Figure 11-7: Historical and 2013 cumulative TSS yield from Villa Park Outlet for stormflow, baseflow, and combined baseflow + stormflow.
Lake McCarrons
2013 CRWD Stormwater Monitoring Report 248
Total Phosphorus (TP)
In 2013, the total TP load from April-October (343 lbs) was the largest annual load ever recorded at Villa Park Outlet since monitoring began in 2006 (Figure 11-8; Table 11-2). TP loading at Villa Park Outlet primarily occurred during storm events in 2013 (251 lbs; 73% of total TP load). Total baseflow TP loading (92 lbs) was 27% of the total load. Drastic increases in annual TP loading at Villa Park Outlet in 2013 are likely related to increases in annual precipitation (particularly in May and June) as well as the pond dredging activities. For average monthly TP storm concentrations at Villa Park Outlet in 2013, the highest average concentrations were observed in June (0.422 mg/L), July (0.452 mg/L), and October (0.395 mg/L)(Figure 11-9). All other months during the monitoring period had average monthly TP storm concentrations well-above the historical averages from 2006-2012 (except September). Historically, March, July, August, and September have the highest average monthly storm TP concentrations.
Figure 11-8: Historical total monitored TP loads at Villa Park Outlet for baseflow and stormflow from 2006-2013.
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Lake McCarrons
2013 CRWD Stormwater Monitoring Report 249
Figure 11-9: Monthly average storm sample TP concentrations in 2013 for Villa Park Outlet and historical averages (2006-2012).
The 2013 stormflow cumulative TP yield trends (Figure 11-10) were similar to Villa Park Outlet stormflow cumulative water yield results in Figure 11-4. Storm TP yields increased dramatically in June 2013 due to the significant amount of precipitation that occurred during that time period (Figure 11-10). Storm TP yields tapered off from August to September due to the extended dry period during those months. The 2013 cumulative baseflow TP yield in Figure 11-10 also mostly follows the steady trend shown by baseflow cumulative water yield results in Figure 11-4. A noticeable increase in baseflow TP yields occurred during the end of August 2013 during the extended dry period. Overall, the 2013 combined stormflow and baseflow cumulative TP yield for 2013 showed a different trend than the historical mean (2006-2012) (Figure 11-10). This is also likely due to a higher than average precipitation year, the intense precipitation events in May and June, and the effects of the dredging activities on discharge.
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Figure 11-10: Historical and 2013 cumulative TP yield from Villa Park Outlet for stormflow, baseflow, and combined baseflow + stormflow.
Lake McCarrons
2013 CRWD Stormwater Monitoring Report 251
Total Nitrogen (TN)
The stormflow loading trends for 2013 cumulative TN yields (Figure 11-11) were commensurate with water yield trends (Figure 11-4). Storm TN yields increased dramatically in June 2013 due to increases in precipitation that occurred during that time period (Figure 11-11). Storm TN yields trends decreased from August to September due to the extended dry period. The trend for baseflow cumulative TN yields (Figure 11-11) also mostly follows the steady trend shown by baseflow cumulative water yield results in Figure 11-4. Noticeable increases in baseflow TN yields occurred in mid-May 2013 (spring thaw and ice out) and the end of August 2013 (an extended dry period). Overall, the 2013 combined stormflow and baseflow cumulative TN yield trend for 2013 varied significantly than the historical mean (2006-2012) (Figure 11-11).
Lake McCarrons
2013 CRWD Stormwater Monitoring Report 252
Figure 11-11: Historical and 2013 cumulative TN yield from Villa Park Outlet for stormflow, baseflow, and combined baseflow + stormflow.
Lake McCarrons
2013 CRWD Stormwater Monitoring Report 253
Chloride (Cl-)
For Cl-, cumulative yields during storm events sharply increased mid-May and mid-July 2013 ( Figure 11-12). Storm Cl- yields increased steadily in 2013, though began plateauing the beginning of August 2013 through October 2013 due to the extended dry period during those months. Baseflow increases in cumulative Cl- yield were steady for the monitoring period (April to November) (Figure 11-12). Slight baseflow Cl- yield increases were apparent mid-May 2013. Overall, the 2013 combined stormflow and baseflow cumulative Cl- yield for 2013 was significantly greater than the historical mean (2006-2012), even though it started below average (Figure 11-12). This could be attributed to the higher than average precipitation year as well as an extended spring of snowmelt that was laden with road salt from road de-icing in the winter months.
Lake McCarrons
2013 CRWD Stormwater Monitoring Report 254
Figure 11-12: Historical and 2013 cumulative Cl- yield from Villa Park Outlet for stormflow, baseflow, and combined baseflow + stormflow.
Lake McCarrons
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11.3 2013 MONITORING SUMMARY – LAKE MCCARRONS OUTLET
The Lake McCarrons Outlet has been monitored since 2005. In 2013, Lake McCarrons Outlet was monitored for flow from April 29 to November 2, 2013 (Figure 11-15). During this period, the lake had outflow from April to mid-August. From mid-August to mid-October 2013, the lake did not have outflow due to an extended dry period. In total, Lake McCarrons discharged 38,664,000 cf of water in 2013, which was significantly greater than all preceding monitoring years (Table 11-1) and the historical average of 22,982,425 cf. Table 11-1: Historical (2005-2013) stage and discharge at the Lake McCarrons Outlet monitoring station.
Year Average Stage (ft) Discharge (cf)2005 0.16 83,156,6302006 0.10 8,603,9542007 0.13 18,831,1562008 0.07 4,888,5482009 0.11 9,673,9892010 0.23 13,998,9002011 0.41 21,723,8002012 NA NA2013 0.39 38,664,000Historical Average 0.17 22,982,425NA: Not Available
Lake McCarrons
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Table 11-2: Villa Park Outlet monitoring results for 2006-2013.
Actual number less than value (<)Actual number greater than value (>)Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit.
Figure 11-16: 2013 Lake McCarrons Outlet level, discharge, and precipitation.
Lake McCarrons
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12 CONCLUSIONS & RECOMMENDATIONS
12.1 CONCLUSIONS
In 2013, stormwater discharging from CRWD was measured to be more polluted than the Mississippi River at Lambert’s Landing. High stormwater pollutant levels contribute to the various water quality impairments found in CRWD lakes and the Mississippi River. Additionally, when compared to the National Stormwater Quality Database, CRWD stormwater in 2013 was typically more polluted with sediment, bacteria, and nutrients (phosphorus and nitrogen) than other urban watersheds across the nation. The 2013 monitoring season was the fourth year since 2010 that six CRWD monitoring sites (St. Anthony Park, East Kittsondale, Phalen Creek, Trout Brook-East Branch, Trout Brook-West Branch, and Trout Brook Outlet) continuously collected data year-round from January through December. Therefore, the total recorded annual discharge and pollutant loads for these sites were higher from 2010-2013 than the annual data recorded from 2005-2009. Large precipitation events in mid-May and mid-June 2013 generated the majority of stormflow at all CRWD monitoring sites and contributed a significant portion of the annual yield of TSS, TP, and TN. A drier than average August through September resulted in reduced pollutant loading during this period. Historically, TSS, TP, and TN yields tend to increase during the fall months, likely as a result of leaf litter decomposition. Most sites in 2013 did not reflect this trend since there was very little precipitation following leaf-off in Fall 2013. Therefore, runoff in Spring 2014 may contain large yields of TSS, TP, and TN as remaining debris stored over the winter is flushed into the system by snowmelt and early season storms. The Trout Brook subwatershed recorded the highest total discharge and total TSS and TP loads in 2013 in comparison to all other monitored CRWD subwatersheds, though it also has the largest total drainage area. This result closely corresponds to trends identified in previous monitoring years. TSS and TP loads from the Trout Brook-East Branch subwatershed, in particular, were significantly greater than the historical average for the site. Localized construction activities within the Trout Brook-East Branch subwatershed can likely be related to the increased sediment and nutrient transport. For many sites, the TP and TSS loads from 2010-2012 generally showed a downward trend each year. In 2013, sites generally showed increases in TP and TSS loads with many recording the highest total loads since full year monitoring began in 2010, likely due to the higher than average total precipitation and snowmelt in comparison to previous years.
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Past monitoring of the Villa Park subwatershed identified it as a prominent source of TP to Lake McCarrons. In 2013, the Villa Park Wetland System underwent a major dredging project aimed at increasing pond depth and water residence time in order to improve the water quality of flow into Lake McCarrons. The total annual TP and TSS loads in 2013 were the highest on record, with the exception of 2010. The high TP and TSS loads could be a result of several factors, including high intensity storms, increased precipitation, and dredging activities. Future monitoring will be needed to determine the long-term effects of the wetland improvements. In 2013, snowmelt made up a larger portion of discharge, TSS load, and TP load at all sites monitored year-round (East Kittsondale, Phalen Creek, St. Anthony Park, Trout Brook-East Branch, Trout Brook-West Branch, and Trout Brook Outlet). A greater snowpack depth during the 2012-2013 winter may have contributed to this observation. Additionally, in 2013, a greater effort was made to sample snowmelt events and to standardize how snowmelt discharge volumes are quantified. Future years’ results will show if the increases seen in 2013 are a better representation of snowmelt’s contribution to the yearly totals or if 2013 was unique in comparison to other years. In 2013, the average stormflow toxicity of copper and lead at all CRWD monitoring sites exceeded the MPCA toxicity standard, with the exception of Como 7 and Villa Park. Toxic levels of zinc are also of concern during stormflow events at some sites, with East Kittsondale, St. Anthony Park, and Como 7 exceeding the MPCA toxicity standard. Average cadmium, chromium, and nickel toxicity at all sites under all flow conditions did not exceed the MPCA toxicity standard. Monitoring has shown that cadmium, chromium, and nickel concentrations are historically not a concern at CRWD monitoring sites. In general, bacteria levels during 2013 storm events were found to exceed MPCA surface water maximum numeric standard at most monitoring sites. In some cases, bacteria results were 100-1000 times greater than the standard. Baseflow bacteria samples typically did not exceed the standard. Cl- levels were monitored year-round in 2013 at all CRWD sites. Large increases in Cl- concentrations were observed during snowmelt periods due to road salt application. Because snowmelt occurred over a longer period of time in 2013, the increases in Cl- yield were also spread over a longer period of time compared to the historical trend. CRWD stormwater ponds were able to provide adequate water storage while maintaining surface levels commensurate with previous monitoring years. Stormwater ponds experienced slight increases in water levels during large storm events; however, excess water generally drained within 72 hours.
12.2 RECOMMENDATIONS
It is the goal of CRWD to continually improve the monitoring program with new ideas in order to advance the program in quality, efficiency, and data application. The monitoring program aims to collect and analyze high quality data from multiple locations to better understand the
2013 CRWD Stormwater Monitoring Report 267
water quality in individual subwatersheds as well as the watershed as a whole. Data collection and analysis through the monitoring program helps to further CRWD’s mission “to protect, manage and improve the water resources of the Capitol Region Watershed District.” In 2013, CRWD achieved many of the goals stated in the 2012 Monitoring Report, including:
Collaboration and Partnerships: o CRWD worked collaboratively with the University of Minnesota (Department of
Ecology, Evolution, & Behavior) on a variety of projects that aimed to further analyze CRWD monitoring data using statistical methods (Janke, 2013).
o CRWD partnered with Mississippi River Watershed Management Organization (MWMO) to share monitoring and data analysis methods.
Monitoring Program Evaluation: o CRWD conducted a Monitoring Program Review in October 2013 to analyze and
refocus the goals, methods, and deliverables of the CRWD Monitoring Program. o Seventeen recommendations were developed by CRWD staff.
Methods in Data Analysis:
o For the 2013 Stormwater Monitoring Report, CRWD staff developed and integrated expanded analysis of the 2013 data, including: Using monthly average concentrations for loading tables; Cumulative loading plots for pollutants of concern; Percent metals toxicity exceedence analysis.
o Changes in data analysis methods were based on analysis and recommendations included in Janke (2013).
Monitoring Equipment and Technology Improvements: o In 2013, CRWD invested in new technology and monitoring equipment designed
to improve data quality and efficiency. o All full water quality monitoring sites received equipment upgrades.
Monitoring Site Locations:
o In 2013, CRWD evaluated each monitoring station to determine if the data being collected at each site was contributing to current monitoring goals.
o CRWD eliminated monitoring locations that were no longer meeting the goals of the monitoring program or a specific project.
Evaluation of Laboratory Services: o CRWD began exploring alternative laboratory services in 2013. o Testing of duplicate samples to Braun Intertec began in October 2013. o CRWD will utilize Braun Intertec for illicit discharge sample analysis and E. coli
testing in the future as needed. o CRWD will continue submitting samples to MCES in 2014.
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For 2014, CRWD developed several goals and recommendations during the 2013 Monitoring Program Review that are aimed at improving the monitoring program’s efficiency as well as CRWD’s water quantity and quality dataset. Goals for 2014 are:
1. CRWD will establish AC power connection and remote data access to Trout Brook-East Branch, Trout Brook-West Branch, and Trout Brook Outlet in 2014 in order to increase data collection efficiency and data quality.
o These sites will act as pilot projects to explore the feasibility for connecting other monitoring sites in the future.
2. CRWD will consider adjusting parameters and frequency of monitoring at site locations
where data is no longer needed.
3. CRWD will investigate opportunities for monitoring in unmonitored CRWD subwatersheds to establish full water quality monitoring stations at new site locations, including:
o Hidden Falls subwatershed o Trout Brook Nature Sanctuary
4. CRWD will consider analyzing water quality samples for additional parameters not
currently analyzed, such as: bacteria/microbial source tracking, oil/grease, trash, PAHs, contaminants of emerging concern.
5. CRWD will evaluate the sampling season schedule to potentially: o Reduce the total number of monthly baseflow sampling events; o Target specific precipitation events for sampling for storm volume and intensity.
6. CRWD will develop and implement a CRWD Monitoring Quality Assurance Program
Plan (QAPP) in 2014 to ensure data quality. The QAPP will act as a primary guidance document to:
o Define field and laboratory quality assurance goals and procedures; o Summarize monitoring program goals, design, sampling methods, analytical
procedures, and data review protocols.
7. CRWD will begin developing a monitoring database for improved data organization, data accessibility, data querying, and data analysis.
8. CRWD will seek to enhance partnerships with the City of Saint Paul, Ramsey County,
other local urban watershed districts, and research groups (e.g. University of Minnesota) to broaden our understanding of urban hydrology and pollutant loading.
9. CRWD will document illicit discharges throughout the watershed and work with District
municipalities to eliminate other potential sources of pollution.
10. CRWD will work with the MPCA and monitor chloride pollution in stormwater to contribute data to the Twin Cities Metro Area Chloride Project (MPCA, 2012b).
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REFERENCES Barr Engineering Company (Barr), 2013. 2012 Water Quality Data Review. Minneapolis, MN. Capitol Region Watershed District (CRWD), 2012. Stormwater BMP Performance Assessment and Cost-Benefit Analysis. Saint Paul, MN. Capitol Region Watershed District (CRWD), 2010. CRWD 2010 Watershed Management Plan. Saint Paul, MN. Capitol Region Watershed District (CRWD), 2002. Como Lake Strategic Management Plan. Saint Paul, MN. Capitol Region Watershed District (CRWD), 2000. Watershed Management Plan 2000. Roseville, MN. City of St. Paul Surveyor’s Office, 2011. Survey records. Accessed on-line from http://survey.ci.stpaul.mn.us/survey_records1.html. Saint Paul, MN. Community Collaborative Rain, Hail & Snow Network (CoCoRaHS), 2014. Maps: Daily Precipitation. Accessed on-line from http://www.cocorahs.org/Maps/ViewMap.aspx?state=usa ESRI, 2011. ArcGIS 9.3 Redlands, CA, USA. Janke, B.D., 2013. Summary and Analysis of Water Quality Data from the Capitol Region Watershed District’s Stormwater Monitoring Program, 2005-2012. University of Minnesota—Department of Ecology, Evolution and Behavior: St. Paul, MN. Kloiber, S.M., 2006. Estimating nonpoint source pollution for the Twin Cities Metropolitan area using landscape variables. Water, Air, and Soil Pollution. 172: 313-335. Maestre, A. and Pitt, R., 2005. The National Stormwater Quality Database, Version 1.1, A compilation and Analysis of NPDES Stormwater Monitoring Information. Center for Watershed Protection: Ellicott City, MD. Prepared for US EPA, Office of Water, Washington, D.C. Massa, S., Brocchi, G.F., Peri, G. Altieri, C. and Mammina, C., 2001. Evaluation of recovery methods to detect faecal streptococci in polluted waters. Letters in Applied Microbiology. 32: 298-302. Metropolitan Council Environmental Services (MCES), 2013. Environmental Information Management System. St. Paul, MN.
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Minnesota Climatology Working Group (MCWG), 2013. St. Paul Campus Climatological Observatory: 15-minute precipitation data. Accessed on-line from http://climate.umn.edu/doc/observatory.htm Minnesota Climatology Working Group (MCWG), 2014. Minneapolis/St. Paul Metro Snow Resources. Accessed online from http://climate.umn.edu/doc/twin_cities/twin_cities_snow.htm Minnesota Department of Natural Resources (DNR), 2014a. 2013 Lake Ice Out Dates. Accessed on-line from http://www.dnr.state.mn.us/ice_out/index.html?year=2013. Minnesota Department of Natural Resources (DNR), 2014b. Median Lake Ice Out Dates. Accessed on-line from http://www.dnr.state.mn.us/ice_out/index.html?year=median Minnesota Pollution Control Agency (MPCA). 2013. TMDL Project: Lake Pepin – Excess Nutrients. Accessed on-line from http://www.pca.state.mn.us/index.php/water/water-types-and-programs/minnesotas-impaired-waters-and-tmdls/tmdl-projects/lower-mississippi-river-basin-tmdl-projects/project-lake-pepin-excess-nutrients.html Minnesota Pollution Control Agency (MPCA), 2012a. Final TMDL list of impaired waters. Accessed on-line from http://www.pca.state.mn.us/index.php/view-document.html?gid=8281. Saint Paul, MN. Minnesota Pollution Control Agency (MPCA), 2012b. Metro Area Chloride Project. Accessed online from http://www.pca.state.mn.us/index.php/view-document.html?gid=16384. Minnesota Pollution Control Agency (MPCA). 2012c. South Metro Mississippi River Total Suspended Solids Total Maximum Daily Load Draft. Accessed on-line from http://www.pca.state.mn.us/index.php/view-document.html?gid=15794. Minnesota Pollution Control Agency (MPCA), 2010. Draft TMDL list of impaired waters. Accessed on-line from http://www.pca.state.mn.us/index.php/view-document.html?gid=8260. Saint Paul, MN. National Weather Service (NWS), 2011. New 1981-2010 Climate Normals. Accessed on-line from http://www.crh.noaa.gov/mpx/?n=mpxclimatenormals National Weather Service (NWS), 2013. National Weather Service Climate data. Accessed on-line from http://www.weather.gov/climate/index.php?wfo=mpx National Weather Service (NWS), 2014a. Local Climate Records. Accessed on-line from http://www.crh.noaa.gov/mpx/Climate/MSPClimate.php National Weather Service (NWS), 2014b. Twin Cities Snowfall Records. Accessed on-line from http://www.crh.noaa.gov/mpx/?n=mspsnowfall
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Minn. Stat. § 7050.0222 (2012). Minnesota Administrative Rules: Specific Water Quality Standards for Class 2 Waters of the State; Aquatic Life and Recreation. Accessed on-line from https://www.revisor.mn.gov/rules/?id=7050.0222 United States Environmental Protection Agency, 2013. Current national recommended water quality criteria. Accessed on-line from http://www.epa.gov/waterscience/criteria/wqcriteria.html
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APPENDIX A: CLIMATE SENSITIVITY ANALYSIS
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APPENDIX B: METAL STANDARDS BASED ON HARDNESS
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APPENDIX B METAL STANDARDS BASED ON HARDNESS
Metals standards for cadmium, chromium, copper, lead, nickel, and zinc were calculated on an
individual site basis for the entire monitoring season (yearly) as well as for base, storm, and illicit
discharge event types (Table 42). Listed below are the equations used to calculate the event type
and yearly metals standards for cadmium, chromium, copper, lead, and zinc. Average hardness
concentrations for each individual monitoring site were used in the calculations, which is why
each site has a different standard. To convert from micrograms (µg) to milligrams (mg), the
standard was multiplied by the conversion factor of
.
(
⁄ ) [ (
⁄ )]
(
⁄ ) [ (
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(
⁄ ) [ (
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(
⁄ ) [ (
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(
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The Minnesota Rules also states that for waters with hardness values greater than 212 mg/L, the
chronic standard for nickel shall not exceed 0.297 mg/L. For those event types or yearly
averages which have average hardness values which exceed 212 mg/L, the nickel standard for
those event types or year was set equal to the state standard of 0.297 mg/L. If the average
hardness value was less than 212 mg/L, the following equation was used to calculate the nickel
standard:
(
⁄ ) [ (
⁄ )]
2013 CRWD Stormwater Monitoring Report 277
Table B-1: 2013 Metals Standards Based on Average Hardness.
Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District.
DATE: May 15, 2014 TO: CRWD Board of Managers FROM: Anna Eleria, Water Resource Project Manager RE: Award Bid for the Highland Ravine Stabilization Project
Background In late March, CRWD’s Board of Managers authorized solicitation of bids for the Highland Ravine Stabilization Project that was contingent on securing easements and agreements from all homeowners and the City of Saint Paul. They were approved by CRWD’s attorney and fully executed in early April. Issues Bidding for the project extended over a three-week period from April 18 to May 12, 2014. CRWD received bids from three contractors: 1) Blackstone Contractors - $515,564.50; 2) Lametti & Sons, Inc. - $587,700; and 3) Sunram Construction - $312,622. The engineer’s estimate of construction cost was $300,700. Sunram Construction has worked with Wenck on stabilization projects for several organizations including Coon Creek WD, Minnehaha Creek WD and Shingle Creek WMO. In addition, Sunram was CRWD’s contractor for the Williams Street Project that was completed in 2012. CRWD staff recommends the Board award the project to Sunram Construction who is the lowest, responsible, qualified bidder. Based on updated cost estimates for construction and upcoming engineering services (discussed in the following Board agenda item), the project budget table has been updated below.
Project Cost Engineering – Design $65,000 Construction (Ravines 1, 2 and 3) $330,700 Engineering – Construction Administration and Observation $85,300 TOTAL COSTS $481,000 Funding Sources Cost CWF Grant $150,000 CRWD $331,000 TOTAL FUNDING $481,000
Action Requested Authorize the Board President and Administrator to execute a Notice of Award and an Agreement with Sunram Construction for the Highland Ravine Stabilization Project subject to the review and approval of the Ramsey County Attorney; and authorize the Administrator to execute change orders in an amount not to exceed $33,000. W:\06 Projects\Highland Ravine\Board-CAC Memos\BM Highland Ravine Bid Award 05-21-14.docx
May 21, 2014 Board Meeting V. Action Item – C) a. Award Bid
for the Highland Ravine Stabilization Project – (Eleria)
Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District.
DATE: May 15, 2014 TO: CRWD Board of Managers FROM: Anna Eleria, Water Resource Project Manager RE: Approve Contract Amendment for Engineer for Highland Ravine Stabilization Project
Background In early November 2012, CRWD’s Board of Managers approved Wenck Associates as the engineer for the Highland Ravine Stabilization Project for an original contract amount of $45,476. To date, CRWD has approved four contract amendments for additional engineering work at cost of $15,744 for a total engineering budget of $61,220. The additional work included stabilization designs for ravines discovered during field work, addressing multiple rounds of comments, and covering other design changes that were outside the original scope of work. Issues CRWD staff is requesting the Board approve a contract amendment for Wenck Associates for two reasons: additional design changes requested by CRWD staff and upcoming engineering work during construction. Since the last approved contract amendment in Nov. 2013, CRWD staff requested Wenck complete three out of scope work items, which included revising the design of the stormwater pond in Ravine 1 to avoid removal of a large basswood tree as requested by the homeowners, eliminating the stabilization design of two gullies in Ravine 3 since an easement could not be obtained from the affected homeowner, and attendance at a second pre-bid meeting for tree removal subcontractors. The cost for these items is $3,363.56. See attached Wenck memo. Wenck has prepared the attached proposal for construction engineering services which includes a significant amount of time for construction observation and meetings, review of contractor submittals, pre- and post-construction inspections of Deer Park foundations, construction staking, final construction report, and project management. The estimated cost for these services is $85,327. CRWD staff is recommending the Board approve a Wenck contract amendment in the amount of $88,691 for several design changes and construction engineering services. Action Requested Approve Contract Amendment #5 for Wenck Associates, Inc. for the Highland Ravine Stabilization Project in an amount not to exceed $88,691 for a total contract budget of $149,911; and authorize the Administrator to execute contract amendments in an amount not to exceed 10% of the construction engineering services budget. encs: Scope of Work Change Memo dated May 7, 2014
Construction Engineering Services Proposal dated May 15, 2014 W:\06 Projects\Highland Ravine\Board-CAC Memos\BM Highland Ravine Engineer Contract Amendment #5 05-21-14.docx
May 21, 2014 Board Meeting V. Action Item – C) b. Contract Amendment for Engineer of the Highland Ravine Stabilization
Project – (Eleria)
W:\06 Projects\Highland Ravine\Design and Engineering\Wenck Scope of Work and Budget\Design Scope Changes\M ‐ Eleria Anna re Scope Change #6.docx
MEMORANDUM TO: Anna Eleria, Capitol Region Watershed District FROM: Todd Shoemaker, PE, CFM DATE: May 7, 2014 SUBJECT: Scope of work change #6 for Highland Ravine Stabilization Project
INTRODUCTION The purpose of this memorandum is to request additional compensation for out‐of‐scope work. BACKGROUND Capitol Region Watershed District (CRWD) contracted with Wenck Associates, Inc. (Wenck) to provide stabilization plans for multiple ravines adjacent to Highland Park in St. Paul. Wenck has completed design plans and specifications. Bids for the project will be received by CRWD on May 12, 2014. SCOPE OF WORK CHANGE #6 Wenck is requesting a budget change for out‐of‐scope work already completed. Typically, we request approval for out‐of‐scope work before completing the work; after discussion with CRWD staff, however, we chose to complete the work to meet multiple deadlines and ensure the project occurs as planned during 2014. The additional out‐of‐scope work includes:
Shifting the proposed basin to the south to avoid removal of a large tree.
Delete proposed work in Ravines 3A and 3B. An easement could not be secured with the property owner, so this work will no longer be constructed.
Attend a second pre‐bid meeting for tree removal subcontractors to view the project site. The total increase to the budget for these tasks is $3,363.56. This amount is detailed in the table below.
Wenck Associates, Inc. 1802 Wooddale Drive Suite 100 Woodbury, MN 55125‐2937 (651) 294‐4580 Fax (651) 228‐1969 [email protected] www.wenck.com
Technical Memo Scope of work change #6 Highland Ravine Stabilization Project May 7, 2014
2 W:\06 Projects\Highland Ravine\Design and Engineering\Wenck Scope of Work and Budget\Design Scope Changes\M ‐ Eleria Anna re Scope Change #6.docx
Wenck Staff Matthiesen Shoemaker Jonett BoellTitle Sr. Engineer PM/WR Eng LA CAD
Hourly Rate $179 $144 $101 $144 $93TASK 1 Data Collection and Review $
TASK 01 TOTAL: $0.00
TASK 2 Field Work and Site Evaluation $TASK 02 TOTAL: $0.00
TASK 3 Project Design $A Shift pond to the south $2,100.00 7 7 $84B Delete Ravine 3A and 3B work and adjust bid quantities $600.00 1 3 $24
TASK 03 TOTAL: $2,700.00
TASK 4 Construction Bidding $A Attend pre-bid meeting for subcontractors $663.56 2.5 2.5 $51
TASK 04 TOTAL: $663.56
TASK 5 Technical Support for Easement Agreements $TASK 05 TOTAL: $0.00
TASK 6 Permitting $TASK 06 TOTAL: $0.00
TASK 7 Project Coordination and Meetings $TASK 07 TOTAL: $0.00
PROJECT TOTALS $3,363.56 0 10.5 2.5 10 0 $159
Admin ExpensesTASK ID TASK DESCRIPTION
May 15, 2014
Ms. Anna Eleria
Water Resource Specialist
Capital Region Watershed District
1410 Energy Park Drive, Ste 4
St. Paul, MN 55108
Re: Highland Ravine Construction Administration Proposal
Ms. Eleria:
Wenck Associates, Inc. (Wenck) submits this proposal to assist Capitol Region Watershed District
(CRWD) in construction of the Highland Ravine Stabilization project. The proposal includes company
background, our proposed scope of work, schedule and a breakdown of estimated costs.
Company Overview
Wenck is 100% employee‐owned Minnesota corporation. Founded in 1985, we have steadily grown
to over 200+ engineers, scientists, and support staff at three offices in Minnesota, three offices in
North Dakota, one office in Georgia, and two offices in Wyoming. Wenck's mission is to deliver
strategic solutions with unmatched service. We strive to delight our clients by being responsive,
reliable and proactive, thereby adding the greatest value possible to CRWD.
CRWD will enjoy the following benefits by selecting Wenck to perform this work:
• No learning curve –Wenck recently completed the Highland Ravine Stabilization project
design plans and is in the process of assisting CRWD in obtaining bids to construct the
project. We have met with affected property owners several times which will allow us to
better direct and coordinate project work.
• Ravine experience – Members of the Wenck Team has supervised construction of numerous
ravines similar to Highland Ravine over the past few years. Currently, we have three on‐
going ravine stabilization projects. This experience enhances our knowledge of contractor
Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District.
DATE: May 15, 2014 TO: CRWD Board of Managers FROM: Mark Doneux, Administrator RE: CAC Framework
Background
The CAC had a drop off in attendance in 2013. This drop in attendance prompted the Co-Chair, Gwen Willems, Manager Reider and I to discuss ideas to reinvigorate the committee. The Board also had a general discussion on this topic at the September 18th Board meeting.
At the October 9th CAC meeting, former State Senator Ellen Anderson facilitated a discussion on ways to reinvigorate the committee. As part of that discussion the Board felt that it would be beneficial to provide input on ways to provide a clearer role and responsibilities for the CAC.
Issues
Staff have been working with the CAC to develop an orientation packet to be used to help recruit and welcome new members. The packet includes a Framework document to be used to guide the work of the CAC and outlines the roles and responsibilities of the CAC. The Framework will serve as a stand-alone document. CAC and staff will update the Orientation Packet as needed.
Action Requested
Adopt CAC Framework
enc: Final Draft CAC Framework
W:\04 Board of Managers\Board Memo Ideas for CAC Framework 5-15-14.docx
The Board will make a concerted effort to ensure that the CAC includes equal
representation from residents throughout the watershed.
The Board may appoint interested parties who do not reside within the District to serve at
their pleasure.
The Board will appoint new CAC members based on a candidate’s interest, availability,
unique skills or experiences and ability to meet the District’s goal of CAC membership
diversity.
CAC organization
The CAC will elect its own leadership.
The CAC will create, update and operate under a set of bylaws that are adopted by the
committee and approved by the Board.
CAC initiatives
The CAC will undertake, in addition to roles and responsibilities, a number of its own initiatives
that enhance its knowledge base and create more cohesion between committee members. These
initiatives could include:
Recruit new CAC members and maintain an orientation packet.
Sponsor guest speakers at CAC meetings.
Increase interaction with neighborhoods, receiving information and sharing it in two-way
communication.
Interact more with local government units, Saint Paul District Planning Councils,
commissions and committees.
Sponsor an awards program to recognize outstanding District citizens, partners and
projects in the district.
Stay abreast of water resource issues by attending MAWD or other natural resource
conferences.
Attend more tours of projects/features in CRWD, increasing the number of tours in the
watershed to at least two per year with the second tour focused on a particular project or
facility.
Participate in legislative activities that impact the District.
Participate in public education about CRWD and its projects.
Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District.
DATE:
TO:
FROM:
RE:
May 15, 2014
CRWD Board of Managers
Gustavo Castro, Water Resource Specialist
2014 Stewardship Grant Program Improvements
Background
Over the past year CRWD staff has been reviewing the Stewardship Grant program to identify ways it
can be improved. On March 19, 2014 the CRWD Board of Managers approved four actions that were
identified for improvement, including: outreach/education, design efficiency, and grant project funding.
One of the approved actions was the use of a calculator to help determine grant awards for water quality
improvement projects within the District. Instead of focusing on the project cost, the calculator factors in
size and area type treated (roof, street, lawn etc.), rainfall depth treated, and provides a bonus based on
promotional/educational value of the project. Currently, high performing, highly visible projects may be
eligible for 100% funding, thereby increasing the likelihood it will be installed.
Issues
After having conducted over 20 site visits during the spring of 2014, CRWD staff is recommending two
additional changes to the Stewardship Grant Program Policies.
Residential vs. Non-Residential: According to the current policies, a single cap is used when
determining grant awards. The maximum grant award for both, residential and non-residential (schools,
churches and businesses) projects is capped at 100% of the total eligible project costs. CRWD staff
believes that a contribution, even if small, from non-residential grant applicants can increase the sense of
ownership of the project, and thus help ensure appropriate long term maintenance of each project.
For-Profit vs. Nonprofit: Since for-profit and public/nonprofit organizations have different missions
and resources to find matching funds, CRWD staff recommends that these characteristics be considered
when determining grant awards.
Action Requested
1. Amend Stewardship Grant Program funding policies as follows:
a) Establish 95% of total eligible project costs as the maximum combined, CRWD and other public sources, award for public and nonprofit organizations,
b) Establish 75% of total eligible project costs as the maximum combined, CRWD and
other public sources, award for for-profit organizations.
W:\04 Board of Managers\Scanned Board Packets PDF\2014\May 21, 2014
May 21, 2014
V. Action Items
E) 2014 Stewardship Grant
Program Improvements
(Castro)
Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District.
DATE: January 23, 2012
TO: CRWD Board of Managers
FROM: Mark Doneux, Administrator
RE: Full Time, Temporary Water Resource Technician Position
Background
The 2014 Work Plan and Budget included a 0.75 FTE for a Permit Inspector and a 0.25 Water Resource
Technician (Monitoring). Currently these two partial positions are being full filled by Corey Poland.
Issues
When this approach was first developed it was envisioned that the 0.75 FTE Permit Inspector position would
be full time for nine months of the year during the construction season and the Water Resource Technician
would be a separate individual brought on during the three summer months. With a single year-round
position the District has been fortunate to have a single person gain experience in both areas bringing about
greater efficiency for both programs. However, due the continued increase in demand for permit inspections
and the regular conflict between permit inspections and water monitoring during wet cycles, staff
recommend the District employee a full-time, temporary technician to assist with monitoring during the three
summer months allowing the Permit Inspector to dedicate the majority of his time and prioritize permit
inspections and close outs. I have draft a Full-Time, Temporary Water Resource Technician Position
Description and it is attached to this memo. The position would be non-exempt (hourly) and the pay range
would be from $12-$14/hour. The period of employment would be roughly June through August. This
position would not accrue PTO nor provide benefits. The total cost is estimated to be $6,000 and funding
would come from the budget 0.25 FTE ($10,810) position in the Monitoring Program Budget.
Requested Action
Authorize the Administrator to advertise and fill the full-time, temporary Water Resource Technician
position.
enc: Draft Water Resource Technician, Full Time Temporary position description
W:\03 Human Resources\POSITIONS\Interns Water Resource\Seasonal Technicians 2014\Board Memo - 2014 Technician 5-15-14.docx
May 21, 2014
Action Item V. F)
Authorize Full Time Temporary
Technician (Doneux)
Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District.
WATER RESOURCE TECHNICIAN, Full Time, Temporary
POSITION ANNOUNCEMENT and POSITION DESCRIPTION
Revised, May 15, 2014
Position Title: Water Resource Technician, Full Time, Temporary
The Water Resource Technician, Full Time, Temporary is an opportunity for a currently enrolled student
or recent graduate pursuing a career in water resources, limnology, biology, or other related field to gain
experience in water resource management and fieldwork. This is full time meaning 40 hours a week but
temporary in nature because the positions are funded through the summer field season of June through
August.
Position Available: One Full Time, Temporary Technician will be hired. The position will be filled for
the time period from approximately June 2, 2014 through Late August/Early September 2014. This time
period is approximate and will be negotiated with the successful candidate. Full time is defined as
meaning the positions are generally 40 hours a week with time and ½ paid for authorized hours worked
over 40 each week. Temporary means the positions will last for approximately three (3) months.
General Duties: Primary duty would be to assist Watershed District Technicians in the operation and
maintenance of storm water quality monitoring sites. The Technician will work under the supervision of
the District Technicians. Most work activities will be outside field work with some office work
downloading and storing data collected in the field.
Position Description: The Water Resource Technician, Full Time, Temporary will assist with storm
water quality monitoring of the Capitol Region Watershed District. The individual responsibilities will
include: Assist with the installation, operation and maintenance of monitoring equipment. This will
include storm water discharges at key outlets to the Mississippi River and storm water Best Management
Practices. Accurately record and store all data collected from monitoring program. Assist with the
monitoring, maintenance and inspections of the District stormwater Best Management Practices
(BMPs). The majority of this intern’s time will be spent outdoors participating in field monitoring and
preparing and/or delivering samples to lab.
Hours of Work: Generally the position requires 40 hours per week. Initial work hours are flexible, but
must be full-time (40 hours per week) during the summer months of June-August. Flexibility is allowed
for students to complete course work in the spring.
Compensation: $12.00 - $14.00 per hour, depending on qualifications and experience. This position
does not include benefits or paid time off. Limited, un-paid time off may be allowed with prior
approval.
Application: Send cover letter, resume and transcript to Bob Fossum at the address listed above.
2
Background and Experience Requirements: Students with water quality monitoring experience
preferred, but not required. Students from Water Resources, Natural Resources and Environmental
Studies, or Biology would be particularly suited. Interns must have their own vehicle for daily use.
Travel within the District is required. Mileage will be reimbursed at District rate.
Prerequisites:
A currently enrolled student or recent graduate.
Individual must provide their own clothing, rain gear, boots, etc.
Interest in pursuing a career in water resources, including water quality monitoring and
fieldwork.
Has completed water resources coursework (e.g. limnology, hydrology, water chemistry, public
health, ecology).
Ability to work full-time during June – August.
Experience using Excel and MS-Word software.
Ability to communicate effectively and work independently.
Must possess a valid driver’s license.
Requires frequent lifting of items weighing up to 60 pounds and walking in rough terrain.
Job requires working in all weather conditions.
Confined space entry is required for this position. CSE training is provided by the District.
W:\03 Human Resources\POSITIONS\Interns Water Resource\Seasonal Technicians 2014\Seasonal Water Resource Technician Position Descipiton 5-15-
14.docx
Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District.
DATE: May 15, 2014
TO: Board of Managers
FROM: Mark Doneux, Administrator
RE: District Office Facility Update
Background
At the May 7, 2014 Board Meeting the Managers approved an agreement for Real Estate Services with
DTZ.
Issues
Staff has worked with DTZ Americas, Inc. to begin planning for the next phase of our real estate search
process. DTZ has drafted a one page CRWD Facility Mission Statement. The Draft CRWD Facility
Mission Statement is based on the Program and Facility Plan developed by CB Richard Ellis. I have
enclosed this draft for your review and comment. I will also update the Board on the status of the Lease
Extension. As part of the Lease Extension, a minor office remodel is proposed to provide adequate
space for our existing staff on the east side of the office and provide two additional work stations for a
possible future summer seasonal staff or GreenCorps Member as well as a small meeting area.
Currently eight staff work on the east side of the office and the attached Preliminary Fit Plan would
provide work stations for 10 as well as a small informal meeting area. The plan is to incorporate the
remodeling work as part of the Lease Extension.
Action Requested
No Action Requested. Provide comments on the Draft CRWD Facility Mission Statement and
Preliminary Fit Plan
enc: Draft CRWD Facility Mission Statement
Preliminary Fit Plan
W:\01 Administration\Facility Management\2014 Phase II Facility Planning\Board Memo - District Office Facility Update 5-15-14.docx
May 21, 2014
VII. Unfinished Business A)
District Office Facility Update
(Doneux)
Facility Mission StatementMay 2014
DTZ Minnesota | 333 S 7th St | Suite 1370 | Minneapolis, MN | 55402 | 612.605.4065 | www.dtz.com
Current Situation:Capitol Region Watershed District “CRWD” currently leases 5,792 square feet located at 1410 Energy Park Drive,Suite 4 and has a lease that will expire in March of 2015. Based on a recent survey of board members andemployees, the majority of respondents believe the facility does not support the culture of the organization.Furthermore, there is a goal to open the space through less constructed elements and lower workstation panels.
Due to the anticipated increase in staff due to additional initiatives there a need to grow and it is expected thatadditional square feet will be required to accommodate CRWD’s mission.
In general, respondents feel that any new facility should be in a safe location, close to public transportation,provide access to natural light for employees and incorporate “green” initiatives in its design.
In order to more closely align with their mission, the Capitol Region WatershedDistrict seeks to find a new facility that will foster their growing team and serve as aplace for people in the district to meet. The space will embody natural designelements, innovative architecture, and connectivity to transit and the community.
Physical Space Needs/Wants:•Additional Office Seating•Garage Storage •Public Art•Design elements •Architecture •Innovative Design •Representative Design •Bike Rack •Indoor Storage •Picnic Area •Exterior Demonstration Area •Outdoor Workspace
Location Needs/Wants:•Proximity to public transport •Ample parking •Provide off hours public access •Safe location •Centrally located within the district •Easily recognized address •Near bike routes •Near central corridor light rail/transit•Near a water resource
Space Features:•Rain garden and native plantings•Better lighting and controls •Secure vehicle storage •Strong design •Access to outdoor light •Rain garden and native plantings •Solar Passive/Active •Light harvesting •Operable Windows •Indoor vehicle storage •Physical Access to outdoors
Culture/Image:•Bright high energy •We want to be here! •Collaborative space for gathering•Soft seating •Creative space•An inspired, positive atmosphere •Problem solving •Technologically advanced•Adaptable
CRWD has expressed a strong interest in a new build to suit opportunity in order to achieve their facilitygoals. However, in order to maximize the potential of creating their ideal environment, existing buildingspoised for redevelopment and leasing options will also be evaluated.
Our Mission is to protect, manage and improve the water resources of Capitol Region Watershed District.
DATE: May 15, 2014
TO: CRWD Board of Managers and Staff
FROM: Mark Doneux, Administrator
RE: May 21, 2014 Administrator’s Report
Administrator Approved or Executed Agreements
Partner Grant Agreement with Urban Roots for youth intern stipends - $12,000.
Consultant Services Agreement with Barr Engineering Co. for the creation of two rain garden renderings -
$3,000.
Board Approved or Executed Agreements
Amendment No. 1 to Consultant Services Agreement with Houston Engineering for Design and Engineering of
the Curtiss Pond Project to include additional work, extend deadline to September 1, 2015 and increase budget
by $49,584 for a total not to exceed $100,584.
Consultant Services Agreement with Outdoor Lab to assist with the maintenance of CRWD’s BMPs - $27, 242.
General updates including recent and upcoming meetings and events
Staff and Board Managers Reider and Jones attended the Great River Gathering Event on May 8, 2014.
Staff will participate in the Saint Paul Public Works Open House on Tuesday, May 20, 2014.
Corey Poland and Lindsay VanPatten completed the Watershed Specialist Training through the University of
Minnesota’s Water Resource Center and Extension.
The Arlington-Rice RSVP boulevard garden planting event will be Saturday, May 31, 2014. Staff will
coordinate the event with help from Great River Greening and District Six Planning Council.
Nominations for Blooming Saint Paul Award are being accepted through June 27, 2014. This is the second year
the CRWD has sponsored the Clean Water Award category that recognizes projects that demonstrate
stormwater runoff reduction, pollution prevention or water reuse.
1.) Upcoming events and meetings
A) Next Board meeting is Wednesday June 4, 2014 from 6:00 – 8:00 pm.
B) Next CAC meeting is Wednesday June 11, 2014 from 7:00 - 9:00 pm.
2.) Project Updates – CRWD staff assisted teaching artists with Public Art Saint Paul with planning for the 2014 PASPider Mobile
Art Series, “Making the Invisible Visible” which includes the themes of stormwater and water quality. The
Mobile Art Lab will be located in Western Sculpture Park every Tuesday afternoon from June 10-Aug. 23. Last
year the Mobile Art Lab served more than 500 children, the average participant age was seven. W:\04 Board of Managers\Correspondence\Administrator's Report 2014\Administrator's Report 5-21-14.docx