Data period: through 2018

Town County Delorme Map # True Basin Flushing Rate Elevation
ETNA PENOBSCOT 22 1 8.08 flushes/yr 207 ft
Maximum Depth Average Depth Surface Area Lake Volume Drainage Area
4 m
(12 ft)
2 m
(6 ft)
122 ha
(301 ac)
2,388,271 m3
(1,936 ac-ft)
21 km2
(8 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 2018 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
1980 39 0.9 1.8 2.4 6
1981 20 50 18 2.1 2.4 2.9 6 2.1 4.1 7.4
1998 19 63 14 36 2.1 3.1 3.5 5 7.3 7.3 7.3
1999 2.1 3.0 4.2 4 1
2000 3.6 3.6 3.6 1
2001 3.1 3.4 3.8 4
2002 70 21 67 24 2.7 3.1 3.3 2 6.7 6.7 6.7
2015 1.4 1.8 1.9 2
2016 1.4 3.1 3.9 4

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
70 20 60 24 36 0.9 2.8 4.2 3.8 2.1 6 7.4

Temperature and Dissolved Oxygen Profiles

Late summer only; limited to eight most recent profiles

Units: Temperature (TEMP) = °C; Dissolved Oxygen (DO) = mg/L
1981-09-03
1998-08-12
2002-08-15
Depth (m) TEMP DO TEMP DO TEMP DO
0 22 7.9 24 6.6 29 8.1
1 21 7.7 24 6.6 29 8.2
2 20 7.4 24 6.6 24 7.9
3 20 7.4 24 6.6 23 6.6
4 20 6.9 21 0.4 22 1.2

Most recent temperature and dissolved oxygen profile plots

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