Groundwater – Vital to Healthy Communities Steve Gaffield – Montgomery Associates Thomas Hovel – City of Fitchburg, WI Madeline Gotkowitz – Wisconsin Geological Survey
Jan 20, 2016
Groundwater – Vital to Healthy Communities
Steve Gaffield – Montgomery AssociatesThomas Hovel – City of Fitchburg, WI
Madeline Gotkowitz – Wisconsin Geological Survey
Topics
• Groundwater basics & current issues
• Madison’s drinking water issues
• Fitchburg’s groundwater issues & approach
• Project examples from Fitchburg
• Discussion!
Wisconsin DNR
TravelWisconsin.com
The water cycle…
aquifer
recharge
Groundwater discharges to springs, streams and lakes
USGS Circular 1139 (1998)
Stream Baseflow
Lakes are the water table…
Wells intercept groundwater and diminish discharge to streams, springs and lakes
Pumping groundwater reduces discharge to surface water somewhere, always.
Changes to the water table and baseflow can be significant
Little Plover River, Portage County
May 2012
Clear Lake, Milton Wisconsin July 2009
Regional groundwater system: Madison, Fitchburg, Verona, Sun Prairie, Middleton, Monona, McFarland
Well 17
Monona Terrace
Upper aquife
r
Deep aquiferConfining unit
Low dissolved oxygen
High dissolved oxygen
Madison Water Utility Board Policies
Madison’s groundwater use 1960 - 2014
2008 water conservation goal: decrease 20% by 2020:73 gal/person/day → 58 gpd (now at 64 gpd)
63,000 wireless transmitters and water meters to comply with PSC requirements, in order to move to a conservation rate structure, ~ $12 M
Madison became the largest city in Wisconsin to offer a residential conservation rate structure
Cost of 4,000 gallons/month will increase 13% ($17.24 to $19.51)
Groundwater and Healthy Communities Planning Challenges
Planning Challenges
What is Important:
• Quality of life
• Health
• Environment
• Balance competing concerns• Resource-based neighborhood plans• Today, we are concentrating on one aspect important to
our way of life….
…water
Where is Fitchburg?
The Comprehensive Plan sets forth a long-range growth boundary of 50 years. Several Neighborhoods have been established to provide for future growth.
Completed Neighborhood Plans:• North Stoner Prairie (NSP)• McGaw• Northeast (NE)
Each Neighborhood has its own set of challenges arising from its unique natural features
NE—Ephemeral wetland
McGaw—S branch Swan Creek
NSP—Closed depression
Northeast Neighborhood
• Upper and lower aquifer
• Housing to the northeast built on hydric soils
Source: DCI map 9/18/2015
Photo from Ed Minihan
Northeast Neighborhood
Town of Dunn--Meadowview flooding
• Waubesa Wetlands a State Natural Area
• Spring flow• Calcareous fens• Nine Springs and Swan Creeks
Source: madmimi.com
Northeast Neighborhood
McGaw Neighborhood • Maintain stream flow in Swan Creek• Waubesa wetlands• Meet higher density desires & retain sufficient recharge, but be
concerned about higher groundwater levels
North Stoner Prairie Neighborhood
• Closed basin• Emergency pumping overflow• Groundwater mounding• Nine Springs Creek, spring flow
Closed depression flooding in June 2013 following 2” rainSource: MARS
Water recharged at NSPN will flow east-northeast toward Nine Springs Creek
Opportunity to enhance baseflow
Little risk of groundwater flooding to south
• Gradient to Nine Springs Cr is 5x higher than gradient toward Lake Harriett
• Groundwater follows path of least resistance & highest gradient
Source: SAA and MARS
North Stoner Prairie Neighborhood
Groundwater is an important resource
Balance between withdrawal and recharge
Stream base flow
Methods to how that can be accomplished is the next part of the presentation
Well zones of contribution Source: Dane Co Water Quality Plan
Evapotranspiration
Tree Canopy Interception
Surface Runoff
Natural
Urban Water Balance
Stormwater runoff
Developed
Low Impact Development
Stormwater infiltration
NE Neighborhood Plan
Glacial Deposits
Upper Sandstone Aquifer
Lower Sandstone Aquifer Eau Claire Shale
Bedrock surface
Lake Waubesa
City well cased through shale
Northeast Neighborhood
Granite
Urban Groundwater Balance
Groundwater Response
Modified from USGS
?
• Review available data• Install monitoring
wells• Simple analytical
equations• Computer models
(Bouwer, 2002)
(USGS, 2010)
Evaluating Groundwater Response
Northeast Neighborhood: Flooding Concerns
• Groundwater rise predicted if recharge increased.
• Plan designed to maintain existing recharge
• No rise expected
(RJN Environmental Services)
McGaw Neighborhood: Downstream Resources
• Computer model available
• Increase in recharge with stormwater infiltration
• Increased water supply pumping
McGaw
Where Does Groundwater Go?
McGaw
Partial Offset of Pumping Increase
• 2 in/yr recharge increase predicted
• Water demand scenarios: low, mod & high
• Streamflow losses limited to 1-5%
North Stoner Prairie Groundwater Concerns
Closed depression flooding
Basement flooding
Borings and Monitoring Wells
County Water Table Map
• Water table slopes east• Consistent with borings
& wells• Land rises to east• No flooding impacts
expected in adjacent neighborhood
• Recharge will benefit Nine Springs Creek
(WGNHS)
West: groundwater shallow
East: groundwater > 20 ft
“Take Homes”
• Groundwater is an important resource for people and nature.
• Groundwater should be considered in urban water management.
• Managing urban land use and groundwater requires a balancing act.
Why Bother?
• Drinking water quality and quantity
• Quality of life & property values
• Mental & social benefits of natural areas
• Physical & economic benefits
(American Rivers)
http://depts.washington.edu/hhwb/