Annual Bolton Lakes Watershed Community Forum
Newhoca Lodge October 14, 2014
Northeast Aquatic Research George Knoecklein
Bolton Lakes
Watershed Lower Bolton Lake = 2,379 acres Middle Bolton Lake = 1,946 acres Upper Bolton Lake = 1,293 acres
Specific drainage basins: Lower Bolton = 258 acres Middle Bolton = 532 acres Upper Bolton = 1,243 acres
Percentage upstream basin: Lower Bolton = 88 % Middle Bolton = 71 % Upper Bolton = 100 %
Upper Bolton Lake
Surface area = 50.3 acres Maximum depth = 7 feet Total volume = 350 acre-feet ? Drainage area = 1,242.7 acres Residence time / Flushing rate
0.27 years / 3.7 times per year
Middle Bolton Lake
Surface area = 121 acres Maximum depth = 18 feet Total volume =1,126 acre-feet Drainage area = 1,825 acres Mean depth 9.8 feet Residence time / Flushing rate
0.89 years / 1.1 times per year
Lower Bolton Lake Surface area = 175 acres Maximum depth = 18 feet Total volume =1,668 acre-feet Drainage area = 2,204 acres Mean depth 9.5 feet Residence time/Flushing rate
0.72 years /1.4 times per year
Summary of Morphometric Characteristics
Lake Area -acres-
Volume -acre-feet-
Basin -acres-
% direct
% upstream Retention -years-
Flushing Rate
Upper 50 (50) 350 1,293 ~ 100 0.27 3.7
Middle 121 (60) 1,126 1,946 29 71 0.89 1.1
Lower 175 (151) 1,668 2,379 11 88 0.72 1.4
Monitored Inlets
26 inlets to Middle and Lower Bolton Lakes monitored for storm event phosphorus inputs
Phosphorus concentrations at three dams
0
5
10
15
20
25
30
35
Mar Apr May Jun Jul Aug Sep
Tota
l Pho
spho
rus
Months 2014
Upper Bolton
Middle Bolton
Lower Bolton
Total phosphorus concentrations in Lower Bolton Lake
0
10
20
30
40
50
60
70
80
90
Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Tota
l Pho
spho
rus
-ppb
Months 2013 - 2014
TopMiddleBottom
Phosphorus concentrations MBL outlet and LBL surface
0
5
10
15
20
25
30
35
40
45
50
Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct
Tota
l Pho
spho
rus
-ppb
Months 2013 - 2014
Middle Bolton Dam
Lower Bolton Surface
Water Clarity in Lower and Middle Bolton
0
0.5
1
1.5
2
2.5
3
3.5
Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov
Wat
er C
larit
y -m
eter
s
2013-14
Solid blue = Mid. Bolton
Water Clarity and Phosphorus in LBL
0
5
10
15
20
25
30
35
40
45
500.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov
Tot
al P
hosp
horu
s
-ppb
Wat
er C
larit
y -m
eter
s
2012 - 2013 - 2014
Water Clarity
Phosphorus
Winter Water Level Drawdown of Middle Bolton Lake
-80
-70
-60
-50
-40
-30
-20
-10
0
Wat
er L
evel
Dow
n (i
n)
Middle Bolton Lake Levels During Deep Drawdowns 2006 - 2010
Bathymetric Map of Middle
Bolton Lake
Approx. location of drain pipe from Middle to Lower Bolton Lake
Approximately 50 acres of shoreline (40%) is exposed
during 6 foot drawdown About 20 acres (16%) during a 3
foot drawdown and 10 acres (8%) during an 1.5 foot
drawdown
Cross-section of Middle Bolton Lake
0
2
4
6
8
10
12
14
16
18
20
0 200 400 600 800 1000 1200 1400 1600 1800
Wat
er D
epth
in fee
t
Distance in feet
Lake level during deep drawdown
Outlet pipe to Lower Bolton Lake -9feet below surface
Watershed Management
Plan
Management of the watershed for what purpose? Lake Water Quality? Control Bluegreen algae blooms? Other ?
17
Creeping Normalcy “Perhaps the commonest circumstance under which
societies fail to perceive a problem is when it takes the form of a slow trend concealed by wide up-and-
down fluctuations” - Jared Diamond
Collapse
Bolton LakesBolton Lakes WatershedUpper Bolton LakeMiddle Bolton LakeLower Bolton LakeSummary of Morphometric CharacteristicsMonitored InletsPhosphorus concentrations at three damsTotal phosphorus concentrations in Lower Bolton LakePhosphorus concentrations MBL outlet and LBL surface Water Clarity in Lower and �Middle BoltonWater Clarity and Phosphorus in LBLWinter Water Level Drawdown of Middle Bolton LakeBathymetric Map of Middle Bolton LakeCross-section of Middle Bolton LakeWatershed Management PlanCreeping Normalcy