Data period: through 2017

Town County Delorme Map # True Basin Flushing Rate
HARTLAND SOMERSET 21 1 1.61 flushes/yr
Maximum Depth Average Depth Surface Area Lake Volume Drainage Area
14 m
(48 ft) 		4 m
(14 ft) 		58 ha
(143 ac) 		2,485,149 m3
(2,015 ac-ft) 		8 km2
(3 mi2)

Secchi Disk Transparency Graphs

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

## [1] "No 2017 Secchi Disk Transparency Data"

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
1990 4.6 5.8 6.8 6
1991 28 73 7.1 6 6.0 6.9 7.5 5
1992 5.6 7.0 8.0 5
2000 24 66 14 25 6.5 6.5 6.5 1 2.9 2.9 2.9
2001 22 66 7.6 7 7 6.8 6.8 6.8 1 2.9 2.9 2.9
2007 12 23 64 7.6 8 19 5.6 6.3 7.3 6 2.6 2.8 2.9
2008 4.5 5.5 6.1 2
2013 20 24 66 7.5 8 10 5.6 5.6 5.6 1 4.3 4.3 4.3

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
16 24 67 7.4 8.6 15 4.5 6.3 8 3.4 2.6 3.2 4.3

Most recent late summer temperature and dissolved oxygen profiles

Units: Temperature (TEMP) = °C; Dissolved Oxygen (DO) = mg/L
1991-08-22
2000-08-16
2001-08-21
2007-08-26
2007-09-03
2008-08-31
2013-08-26
Depth (m) TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO
0 21.2 8.5 22.9 9.0 24.1 7.9 23.3 7.8 22.1 7.2 23.0 7.1 23.2 8.2
1 21.0 8.4 22.9 9.0 24.1 7.9 23.3 7.8 22.1 7.2 22.8 7.1 23.2 8.2
2 20.8 8.3 22.8 8.9 24.0 7.8 21.8 7.9 22.0 7.2 22.8 7.1 23.2 8.2
3 20.8 8.3 22.8 8.9 24.0 7.8 21.4 7.8 21.9 7.2 22.7 7.1 23.1 8.2
4 20.5 8.4 22.8 8.9 23.9 7.7 21.1 7.8 21.9 7.2 22.7 7.0 22.2 7.5
5 20.5 8.4 22.4 8.0 19.5 7.6 21.0 7.6 21.6 7.1 20.2 4.9 19.9 4.9
6 20.2 7.8 17.2 4.8 13.9 6.9 18.6 6.7 19.0 5.8 14.6 2.3 16.6 1.6
7 16.9 5.2 13.9 2.7 10.5 4.7 13.1 4.0 14.2 3.8 10.2 1.9 12.1 0.5
8 11.5 0.9 11.2 1.1 8.7 1.7 9.9 1.2 11.2 1.2 8.5 0.6 10.4 0.3
9 9.5 0.3 9.5 0.3 7.4 0.8 8.8 0.3 9.2 0.2 7.6 0.6 9.5 0.3
10 8.0 0.3 8.8 0.2 8.2 0.2 8.1 0.1 7.2 0.6 8.7 0.3
11 7.8 0.1 8.6 0.2 7.7 0.2 7.8 0.2 7.0 0.6 8.5 0.3
12 7.3 0.1 7.5 0.2 7.7 0.2 7.1 0.7 8.4 0.3
13 7.1 0.1 7.4 0.2 7.6 0.2 7.0 0.6 8.3 0.3
14 6.9 0.6 8.4 0.3

Recent temperature and dissolved oxygen profile plots

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