Data period: through 2017

Town County Delorme Map # True Basin Flushing Rate
WASHINGTON KNOX 13 1 0.7 flushes/yr
Maximum Depth Average Depth Surface Area Lake Volume Drainage Area
11 m
(36 ft)
4 m
(14 ft)
226 ha
(558 ac)
4,883,225 m3
(3,959 ac-ft)
7 km2
(2.8 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
1977 5.8 6.5 6.9 3
1978 5.4 6.6 8.3 5
1979 4.0 30 8.0 6.4 7.0 7.7 6 2.1 2.1 2.1
1980 6.7 7.8 8.9 7
1981 5.0 6.7 7.9 5
1982 4.0 35 5.0 5.5 7.4 8.9 6 1 1.8 1.8 1.8
1983 5.7 6.9 7.9 4
1984 4.6 6.9 7.7 5
1985 4.0 24 6.0 7.0 5.4 7.0 8.3 6
1986 4.8 6.0 6.5 4
1987 5.8 6.4 6.8 5
1988 4.0 26 6.0 3.0 5.3 6.3 7.1 5
1989 4.8 5.7 6.0 2
1990 4.8 6.6 8.5 5
1991 5.0 6.0 6.0 6.0 2
1992 5.3 6.0 7.0 2
1994 6.0 6.5 7.1 3
1995 6.5 6.8 7.1 3
1996 6.2 6.4 7.0 3
1997 6.2 31 7.0 6.5 9.0 5.6 6.6 7.4 2 2.1 2.7 3.5
1998 6.5 7.1 7.9 4
1999 5.2 6.8 6.0 6.0 6.7 7.3 7.9 2 2.0 2.3 2.5
2000 6.0 6.3 6.5 2
2001 4.5 6.9 5.0 5.0 7.6 7.6 7.6 1 4.2 4.2 4.2
2002 6.5 7.0 36 4.0 11.0 6.6 6.7 6.9 1 3.1 3.1 3.1
2003 4.5 6.7 7.0 11.0 7.4 7.8 8.2 2 1.8 1.8 1.9
2006 5.2 5.7 6.5 5
2007 8.0 5.2 34 6.7 5.0 12.0 7.5 7.6 7.6 1 2.4 2.5 2.6
2008 6.0 4.3 37 6.7 8.0 22.0 6.8 6.9 7.0 1 2.8 2.8 2.8
2010 5.2 6.2 7.4 5
2011 6.0 4.5 6.1 6.8 7.5 6 2.3 2.3 2.3
2012 5.0 4.0 10.0 4.3 5.8 7.0 7 5.0 5.0 5.0
2013 4.6 5.8 6.4 4
2014 5.8 6.2 6.4 4
2015 7.0 6.0 38 6.6 6.0 8.0 6.8 5.3 6.6 8.3 9 3.2 3.4 3.7
2016 7.0 5.0 40 6.4 6.0 5.0 6.2 7.5 8 2.4 2.4 2.4
2017 6.0 6.0 40 6.6 5.5 3.5 12.0 5.5 6.0 6.8 7 2.7 2.8 2.8

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
6.8 5 34 6.7 5.8 5.3 9.6 4.3 6.6 8.9 4.1 1.8 2.8 5

Most recent late summer temperature and dissolved oxygen profiles

Units: Temperature (TEMP) = °C; Dissolved Oxygen (DO) = mg/L
2012-09-12
2015-08-18
2015-08-20
2015-09-16
2016-08-25
2017-08-21
2017-08-22
2017-09-23
Depth (m) TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO
0 21 8.5 28 8.1 26 7.9 23 7.9 24 7.8 23 7.8 24 8.3 21 8.5
1 24 8.5 26 8.3 26 8.0 23 7.9 24 7.8 23 7.8 24 8.3 20 8.5
2 21 8.5 25 8.3 26 8.2 23 7.9 24 7.8 23 7.9 24 8.3 20 8.5
3 21 8.5 25 8.3 26 8.4 23 7.9 24 7.8 23 7.9 24 8.3 20 8.5
4 21 8.3 24 8.3 25 8.4 23 7.8 24 7.8 23 7.8 23 8.1 20 8.5
5 21 8.2 24 8.1 24 8.2 23 7.7 24 7.8 23 7.8 23 8.0 20 8.5
6 21 8.3 23 7.0 24 7.4 22 7.7 24 7.6 23 7.3 23 7.8 20 8.4
7 21 8.2 23 5.3 23 6.2 22 7.4 24 7.4 23 7.2 23 7.1 20 8.0
8 21 8.1 22 1.3 20 1.4 22 6.7 23 5.8 20 1.6 20 2.2 20 8.0
9 16 0.2 15 0.7 16 0.1 17 0.1 14 0.1 14 0.6 19 6.5
10 12 0.1 12 0.1 12 0.5 14 0.1
11 11 0.1 11 0.1 12 0.5 12 0.1
12 11 0.1 11 0.1

Recent temperature and dissolved oxygen profile plots

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