Data period: through 2018

Town County Delorme Map # True Basin Flushing Rate Elevation
ST JOHN PLT AROOSTOOK 67 1 19.19 flushes/yr 899 ft
Maximum Depth Average Depth Surface Area Lake Volume Drainage Area
10 m
(33 ft) 		4 m
(11 ft) 		39 ha
(98 ac) 		2,043,700 m3
(1,657 ac-ft) 		3 km2
(1.2 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
1954
1972 6.9 6.9 6.9 1
1989 49 90 6 4.5 5.4 6.4 2 1.2 1.2 1.2
1996 46 100 4 7 7.1 7.1 7.1 1 1.9 1.9 2.0
2001 44 94 8 4 12 6.1 6.1 6.1 1 3.6 3.6 3.6

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
46 94 8 4.7 9.5 4.5 6.4 7.1 1.2 1.2 2.2 3.6

Temperature and Dissolved Oxygen Profiles

Late summer only; limited to eight most recent profiles

Units: Temperature (TEMP) = °C; Dissolved Oxygen (DO) = mg/L
1954-08-05
1972-08-04
1989-08-17
1989-09-01
1996-08-21
2001-08-21
Depth (m) TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO TEMP DO
0 18 8.1 19 7 22.0 9.0 16 9.5 20.8 8.9 21.1 8.5
1 22.0 9.0 19.9 9.0 21.1 8.6
2 22.0 9.0 16 9.5 19.5 8.9 21.1 8.7
3 22.0 9.0 16 9.1 19.0 8.9 21.1 8.7
4 21.5 8.5 17.8 6.8 21.1 8.7
5 16 7.0 17.0 8.5 14 8.7 14.4 4.5 17.4 10.2
6 13 1.8 13 6 12.5 7.2 12 7.8 12.0 3.4 12.4 8.7
7 10.0 3.4 10.2 1.9 9.8 3.3
8 11 1.2 11 2 9.0 1.7 8 1.0 9.3 0.8 8.5 0.7
9 10 0.6 10 2 8.5 0.6 7 0.0 9.0 0.4 7.9 0.2
10 7.9 0.1

Most recent temperature and dissolved oxygen profile plots

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