Data period: through 2018

Town County Delorme Map # True Basin Flushing Rate Elevation
ISLAND FALLS AROOSTOOK 52 1 9.84 flushes/yr 430 ft
Maximum Depth Average Depth Surface Area Lake Volume Drainage Area
14 m
(47 ft) 		4 m
(12 ft) 		1,160 ha
(2,865 ac) 		42,313,751 m3
(34,304 ac-ft) 		21 km2
(8.2 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
1972 14 47 12
1977 2.5 2.5 2.5 1 2.1 2.1 2.1
1978 3.7 4.1 4.3 3
1980 20 80 13 11 3.0 3.4 3.5 3 7.1 7.1 7.1
1981 4.0 4.8 5.0 5
1983 17 15 13 3.4 3.4 3.5 3 3.6 3.6 3.6
1984 14 41 12 2.9 4.0 5.0 4 1.6 2.0 2.5
1985 3.0 3.5 4.0 4
1986 16 55 11 3.0 3.3 3.8 4 1.7 2.3 2.7
1987 3.0 3.0 3.0 1
1988 3.0 3.1 3.4 3
1989 54 20 2.5 2.5 2.5 1 1.0 1.3 2.0
1990 68 6.2 10 3.0 3.7 4.4 1 1.7 1.9 2.1
1991 3.5 4.7 6.0 4
1992 2.5 3.3 4.0 5 2.1 2.1 2.1
1993 16 2.3 3.1 4.0 6 2.7 3.0 3.4
1995 3.0 3.9 4.5 3 3
1996 2.4 2.9 3.5 5
1998 2.3 2.6 2.9 5
1999 16 58 11 11 2.2 3.5 4.3 5 2.8 2.8 2.8
2000 2.1 2.7 3.4 4
2001 19 62 7.6 9 12 2.2 3.1 5.5 5 1.7 1.7 1.7
2002 2.4 3.0 4.0 4
2003 74 22 63 14 9 2.2 2.9 4.1 1 3.1 3.1 3.1
2004 28 24 64 7.5 9 11 4.5 4.5 4.5 1 4.1 4.1 4.1
2005 9 3.1 3.9 4.9 4
2006 9 3.2 3.7 4.3 3
2007 8 3.7 4.2 5.1 5
2008 74 21 59 7.2 17 14 17 2.5 3.0 3.5 3 2.5 2.5 2.5
2009 13 3.2 3.3 3.4 2
2010 11 3.3 3.5 4.1 2
2011 14 2.5 2.9 3.4 2
2012 12 2.6 2.7 2.8 2
2013 62 20 52 7.4 10 11 2.8 3.4 4.1 5 2.8 2.8 2.8
2014 10 3.1 3.7 4.2 4
2015 3.6 4.5 5.5 7
2016 3.8 4.1 4.9 6
2017 8 3.1 4.8 6.3 5
2018 17 20 54 7.2 16 10 4.1 4.4 5.3 5 2.0 2.0 2.0

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
51 19 58 6.9 13 11 12 12 2.1 3.5 6.3 3.6 1 2.8 7.1

Temperature and Dissolved Oxygen Profiles

Late summer only; limited to eight most recent profiles

Units: Temperature (TEMP) = °C; Dissolved Oxygen (DO) = mg/L
2003-08-13
2003-08-19
2003-08-29
2004-08-17
2006-08-22
2008-08-13
2013-08-28
2018-08-28
Depth (m) TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO
0 27 8.5 24 7.4 20 8.4 22 7.7 21 8.0 22 7.4 25 8.5 24 8.4
1 25 8.3 23 7.5 19 8.1 22 7.7 21 7.7 21 7.5 23 8.5 24 8.4
2 24 8.1 25 7.4 20 8.2 22 7.7 21 7.7 21 8.2 22 8.3 23 8.4
3 23 7.5 25 7.4 20 8.1 22 7.8 21 7.8 20 8.2 22 8.2 23 8.3
4 22 6.4 23 7.4 20 8.1 22 7.8 21 7.7 20 6.9 21 7.4 23 8.3
5 21 5.3 22 5.5 20 7.9 22 7.7 21 7.7 20 6.5 20 6.3 23 8.2
6 21 6.0 21 4.1 20 7.8 21 7.3 20 7.6 19 5.9 19 5.0 23 7.5
7 20 3.3 20 3.7 20 7.9 21 6.5 20 7.5 19 5.2 19 4.6 22 6.8
8 19 4.3 19 2.5 20 7.8 20 2.1 20 7.3 18 5.1 18 4.1 22 6.1
9 18 2.0 17 1.3 20 7.9 18 0.8 15 2.0 16 0.7 17 2.9 21 4.8
10 16 1.0 15 0.5 20 5.0 17 0.5 15 1.4 16 0.6 16 1.9 19 0.6
11 15 0.8 15 0.4 16 1.7 17 0.3 15 0.7 15 0.8
12 14 0.3 14 0.4 17 0.1 15 0.5 14 0.3
13 14 0.2 16 0.1 14 0.4 14 0.2
14 14 0.2 16 0.1

Most recent temperature and dissolved oxygen profile plots

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