Site: Whitewater Lake, CAMB015
Location: 49° 15' 26 N, 100° 19' 29 W
Elevation: 457 to 460 m
Biome: Mixed-grass Prairie
Size: 6,070 to 10,320 hectares
Whitewater Lake is in southwestern Manitoba. The two main settlements around the lake are Deloraine and Boissevain.
Soils of the Whitewater Association are developed upon lucustrine sediments. Streams carrying water run-off dumped inorganic material in the lake resulting in sedimentary deposits of sand, silt and clay within the basin. During the time when the lake was at its largest size it apparently had two outlets known as Elgin Creek (northwest of Boissevain) and Medora Creek (north of Deloraine). Post glacial streams once had well defined channels ending at the shoreline of the lake. These streams have since deposited their loads of suspended materials forming alluvial fans, so that the streams end as far as four miles from the shoreline hence the lake has no water outlets.
The topography of Whitewater Lake is generally flat. There are two pronounced sandbars in the northeast corner of the lake with a small vegetated mud bar. There is one island known as Sexton's Island on the north shore. The region is of the Mixed-grass Prairie Biome, generally dry, and experiences annual moisture deficits of about 4-inches.
The dominant nesting and roosing cover is in the form of cattails, bulrushes and Whitetop grass. Upland of the lakeshore, meadowlands of spikerush and sedge give way to Mixed-grass prairie. Vegetation composition, dominant species and distribution of plant species varies as the lake undergoes high water years and drought periods. This can occur in less than 60 years in some cases.
Whitewater Lake is fed from 8 major creeks and streams from the Turtle Mountains to the south. The water is moderately brackish with sodium and magnesium sulfate salts predominating. Whitewater Lake lies in a flat, poorly drained terminal basin. Whitewater has no water outlet hence water is lost through evapotranspiration and possibly seepage. Consequently, lake levels fluctuate violently. With no water outlet, mineral content of the lake can be expected to increase over time. Lake levels can also fluctuate daily due to wind tides or seiches that affect water levels at opposing points on the lake. These tides can have deleterious effects on nesting birds by flooding nesting areas. Ransom and Hochbaum (1972) reported that on July 1 1970, a wind of 35-40 miles per hour moved water 1/8 of a mile beyond the normal waters edge and raised water levels by at least one foot.