 Its elevation is 439 feet (134 meters) above sea level.Senachwine Lake is connected by a shallow channel to adjacent Goose Lake, also a backwater lake of the Illinois River.The drainage, by sudden flood, of a sizable lake of glacial meltwater upon the conclusion of the Wisconsin glacial period left the lower Illinois River valley, including the Senachwine Lake area, as a broad ribbon of relatively impermeable clay and silt bordered by low bluffs.