Melvern Lake and Dam were constructed at a cost of $37,436,530.00 for the primary purpose of providing flood control on the lower Marais Des Cygnes River. As of 2005, Melvern Lake has prevented approximately $220,637,400.00 in downstream flood damages.
Melvern Dam is a rolled earthfill embankment with an impervious clay core making the dam nearly watertight. The dam extends 9,700 feet and rises nearly 125 feet above the river valley. The lake elevation is maintained via a series of hydraulically operated gates located at the bottom of the control tower. The lake water passes through a conduit for approximately 754 feet before entering the Marais Des Cygnes River.
Other authorized purposes include recreation, water supply and fish and wildlife management. The 349 square miles of drainage basin above Melvern Lake is composed primarily of warm-season grasses intermixed with agriculture and hardwood forests. The presence of an upstream prairie ecosystem provides a better than average water quality for Melvern Lake.
Authorized by Congress: 1954
Authorized use: Flood control and water resource development
Drainage basin: Marais des Cygnes River
Tangible benefits: water supply, recreation, fish and wildlife conservation
Under construction: 1967-1972
First recreation season: 1974
Dedication: 1975
Elevation, feet above mean sea level
Top of flood control pool: 1,057
Top of multipurpose pool: 1,036
Surface area, acres
Top of flood control pool: 13,950
Top of multipurpose pool: 6,930
Shoreline, miles (multipurpose pool): 101
Maximum depth, ft. (multipurpose pool): 74
The Dam Type: Rolled earthfill
Length, ft. (overall): 9,700
Height, ft. (above streambed): 125
Width, ft. (base): 915
Width, ft. (crown): 30
Emergency spillway: Uncontrolled chute
Outlet works: Single Horseshoe conduit (11.5 ft.)
Gates: 2 Hydraulically operated gates (6 ft. x 12 ft.)