Data period: through 2018

Town County Delorme Map # True Basin Flushing Rate Elevation
WASHINGTON KNOX 13 1 0.7 flushes/yr 322 ft
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
2018 5.0 36 6.7 6.0 5.3 6.9 9.4 7 3.0 3.0 3.0

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 9.4 4.2 1.8 2.8 5

Temperature and Dissolved Oxygen Profiles

Late summer only; limited to eight most recent profiles

Units: Temperature (TEMP) = °C; Dissolved Oxygen (DO) = mg/L
2015-08-20
2016-08-25
2017-08-21
2017-08-22
2018-08-01
2018-08-14
2018-08-28
2018-09-05
Depth (m) TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO
0 26 7.9 24 7.8 23 7.8 24 8.3 26.1 7.8 26 7.4 25 8.3 24 8.2
1 26 8.0 24 7.8 23 7.8 24 8.3 26.0 7.8 26 7.4 25 8.2 24 8.2
2 26 8.2 24 7.8 23 7.9 24 8.3 25.9 7.8 26 7.4 25 8.1 24 8.2
3 26 8.4 24 7.8 23 7.9 24 8.3 25.8 7.8 26 7.4 24 8.0 24 8.1
4 25 8.4 24 7.8 23 7.8 23 8.1 25.6 7.7 26 7.4 24 7.9 24 8.1
5 24 8.2 24 7.8 23 7.8 23 8.0 24.9 7.3 26 7.4 24 7.8 24 7.8
6 24 7.4 24 7.6 23 7.3 23 7.8 24.4 6.8 26 7.3 24 7.6 24 7.7
7 23 6.2 24 7.4 23 7.2 23 7.1 23.8 5.7 24 3.8 24 6.9 24 7.4
8 20 1.4 23 5.8 20 1.6 20 2.2 19.3 1.3 20 0.6 22 1.7 22 4.7
9 15 0.7 17 0.1 14 0.1 14 0.6 13.9 0.5 14 0.1 15 0.2 16 0.5
10 12 0.1 12 0.1 12 0.5 10.8 0.2 11 0.1 12 0.1 12 0.4
11 11 0.1 11 0.1 12 0.5 9.7 0.1 10 0.1 10 0.1 11 0.4
12 11 0.1

Most recent temperature and dissolved oxygen profile plots

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