General Data of Baldwin Lake

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The following was compiled by the Baldwin Lake Association Water Quality Committee chairman Mike Miller in September 1994 (Edited some in July 1999).

BALDWIN LAKE
Porter Township, in the southeast corner of CASS County Michigan.

Type of Lake - - - - - Natural
River Basin - - - - - St. Joseph
Lake Acres - - - - - 251.82(U.S. Topographic; 266 by Michigan figures)
Maximum depth (feet) - - - - - 55' (non-spring reading)
Mean depth - - - - - 18'
Lake volume (acre feet) - - - - - 4532.76
Watershed area (acres) - - - - - 1555.83
Drainage area (acres) - - - - - 1807.65
Lake-watershed ratio - - - - - 1:6.18
Flushing rate - - - - - 2.94 years
Elevation (lake water) - - - - - 755' above sea level
Longest dimension (feet) - - - - - 7,765'
Bottom type - - - - - Sand/Gravel/Marl

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Watershed Data:
- - - - - Square Miles/Acres = 2.43/1555.83
- - - - - Perimeter Miles = 8.25

Lake Area Data:
- - - - - Square Miles/Acres = 0.39/251.82
Perimeter Miles = 4.57

FLUSHING RATE/TIME:

Total water volume = 4532.76 Acre-Feet (251.82 acres X 18' mean depth est)

Total precipitation on lake and watershed = 251.82 (lake acres) + 1555.83 (watershed acres) = 1807.65 accres.
Average annual precipitation for this area = 34.11 inches (2.8425') X 1807.65 acre = 5138.25 Acre Feet.

Average annual evaporation = 70% of the annual precipitation leaving 30% for flushing. 5138.25 - 3596.78 A.F. = 1541.47 A.F.

Total voulme of Baldwin Lake = 4532.78 A.F. divided by evaporation of 1541.47 A>F> = 2.94 years (total time for a complete water exchange)

**NOTE: Normally the time would be reduced by adding the flowage from Indiana Lake, but due to the outflow to Long Lake, the overall effect balances itself for these computations.