Data period: through 2018

Town County Delorme Map # True Basin Flushing Rate Elevation
OLD TOWN PENOBSCOT 33 1 1.96 flushes/yr 115 ft
Maximum Depth Average Depth Surface Area Lake Volume Drainage Area
8 m
(28 ft) 		3 m
(10 ft) 		2,045 ha
(5,054 ac) 		65,500,000 m3
(53,102 ac-ft) 		195 km2
(75 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
1974 17 40 15 2.1 2.9 3.7 6 2.6 3.6 4.8
1975 18 30 13 2.3 3.3 4.2 7 2.1 3.8 9.2
1976 13 2.1 3.2 4.2 9 1.8 3.6 5.6
1977 15 2.7 3.5 4.2 7
1978 2.9 3.6 4.3 2
1979 3.3 3.8 4.6 6
1980 20 55 22 2.7 3.3 3.5 4 5.0 5.0 5.0
1981 2.7 3.9 5.2 5
1982 2.7 4.1 4.9 5
1983 13 10 4.5 4.5 4.5 1 3.6 3.6 3.6
1989 3.2 3.5 3.7 7
1990 13 61 7.5 12 3.2 3.5 3.9 6 4.0 4.0 4.0
1991 4.0 4.9 5.5 6
1992 3.0 4.5 5.5 6
1993 18 3.0 4.1 6.0 6 1
1994 14 2.7 4.3 6.5 6
1995 3.0 4.3 6.0 6
1996 2.4 3.2 3.4 6
1997 15 65 7.4 11 3.0 4.0 6.0 14 2 2.5 2.5 2.5
1998 2.5 3.6 4.7 8
1999 2.0 3.3 4.2 11
2000 2.0 2.9 4.0 6
2001 2.8 3.8 4.6 7
2002 17 76 15 2.8 3.3 4.0 3 4.9 4.9 4.9
2003 2.5 3.4 4.7 3
2004 2.9 3.3 3.6 4
2005 2.8 2.9 3.4 3
2006 15 2.8 3.0 3.3 3
2007 32 17 64 7.4 14 2.5 3.9 4.8 5 4.0 4.0 4.0
2008 16 2.8 3.2 4.1 5
2009 19 2.3 2.6 3.0 5
2010 17 2.6 3.5 4.6 5
2011 13 17 2.5 3.4 4.2 5 3.1 3.1 3.1
2012 2.5 3.3 4.2 5
2013 2.9 3.2 4.2 5
2015 39 19 70 7.4 11 18 2.8 3.8 4.8 5 6.2 6.2 6.2
2016 18 3.2 3.5 3.7 3
2017 20 2.3 3.0 3.9 4
2018 20 2.2 3.5 4.9 5

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
36 16 58 7.4 14 17 15 14 2 3.6 6.5 5.5 1.8 4 9.2

Temperature and Dissolved Oxygen Profiles

Late summer only; limited to eight most recent profiles

Units: Temperature (TEMP) = °C; Dissolved Oxygen (DO) = mg/L
2015-08-27
2015-09-12
2016-08-30
2017-08-14
2017-08-23
2017-09-08
2018-08-26
2018-09-09
Depth (m) TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO
0 25 8.4 24 7.6 23 8.3 23 8.0 23 7.5 21 8.1 24 8.7 22 8.7
1 24 8.4 23 7.7 23 8.3 23 8.0 23 7.5 19 8.1 24 8.6 22 8.5
2 24 8.2 22 7.6 23 8.2 23 8.0 23 7.5 19 8.0 24 8.5 22 8.4
3 24 8.1 22 7.6 23 8.1 23 7.9 23 7.5 19 7.8 24 8.5 22 8.4
4 24 8.1 22 7.5 23 7.9 23 7.7 23 7.5 19 7.8 23 8.3 22 8.4
5 24 8.0 22 7.4 22 7.7 23 7.6 23 7.5 19 7.6 23 8.2 22 8.3
6 24 8.0 22 7.4 23 7.6 19 7.6 23 8.2 22 8.3
7 22 7.5

Most recent temperature and dissolved oxygen profile plots

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