Data period: through 2018

Town County Delorme Map # True Basin Flushing Rate Elevation
WILLIMANTIC PISCATAQUIS 32 1 1.43 flushes/yr 324 ft
Maximum Depth Average Depth Surface Area Lake Volume Drainage Area
47 m
(155 ft) 		13 m
(43 ft) 		2,658 ha
(6,568 ac) 		349,488,384 m3
(283,335 ac-ft) 		414 km2
(160 mi2)

Secchi Disk Transparency Graphs

Graph Legend: Secchi symbols = average Secchi Disk Transparency Values; tick marks = maximum and minimum values for each year.

Water Chemistry and Trophic State Parameters

Table Legend:

Color: Color (SPU), Alk: Alkalinity (mg/l CaCO3), SpCon: Specific Conductivity (\(\mu\)S/cm), pH: pH (standard units)

TP = Total Phosphorus (\(\mu\)g/L) – EC: Epilimnion Core, SG: Surface Grab, BG: Bottom Grab, PG: Profile Grab

SDT = Secchi Disk Transparency (m) – Min: minimum value, Avg: average value, Max: maximum value, n: number of months with Secchi readings per year, b: number of times Secchi disk was observed touching the bottom of the lake per year

Chl = Chlorophyll-a (\(\mu\)g/L) – Min: minimum value, Avg: average value, Max: maximum value
Year Color Alk SpCon pH TP-EC TP-SG TP-BG TP-PG SDT-Min SDT-Avg SDT-Max SDT-n SDT-b Chl-Min Chl-Avg Chl-Max
1984 4.5 6.2 7.5 5
1988 5.2 6.0 6.7 1
1999 5.0 9 6.3 6.3 6.3 1
2003 7.2 7.9 9.4 6
2004 5 5.8 7.4 8.7 3
2005 4 4.7 5.7 6.6 5
2006 4 6.5 6.9 7.3 3
2007 14 5.9 21 7.1 4 8.1 8.8 9.5 4
2008 4 5.3 7.4 8.5 3
2009 4.7 6.0 7.3 4
2010 6.8 7.9 8.8 4
2011 6.8 8.1 9.0 3
2012 5 6.3 6.5 7.0 3
2013 4 6.0 7.0 7.5 3
2014 6.2 6.9 7.6 3
2016 7.2 8.2 9.2 2
2017 5.2 7.0 8.2 4
2018 16 8.0 27 6.7 4 6.7 7.3 7.7 5 2 2 2

Lake Chemistry and Trophic Summary Data - Overall Summary Values:

Avg Color Avg Alk Avg SpCon pH Avg TP-EC Avg TP-SG Avg TP-BG Avg TP-PG SDT-Min SDT-Avg SDT-Max SDT-n Chl-Min Chl-Avg Chl-Max
15 6.3 24 6.9 6.5 4.3 4.5 7.1 9.5 3.4 2 2 2

Temperature and Dissolved Oxygen Profiles

Late summer only; limited to eight most recent profiles

Units: Temperature (TEMP) = °C; Dissolved Oxygen (DO) = mg/L
2018-08-27
Depth (m) TEMP DO
0 23.8 8.6
1 23.8 8.6
2 23.7 8.6
3 23.6 8.6
4 23.4 8.6
5 23.2 8.5
6 23.0 8.4
7 22.7 8.3
8 20.2 6.7
9 17.1 6.6
10 14.5 6.9
11 12.3 7.6
12 11.2 7.7
13 10.2 7.9
14 9.8 7.7
15 9.1 7.6
16
17 8.5 7.1
18
19 8.4 7.0
20
21 8.2 6.8
22
23 8.0 6.4
24
25 8.0 6.2
26
27 7.9 5.8

Most recent temperature and dissolved oxygen profile plots

Temperature (°C), Dissolved Oxygen (mg/L)