Cedar Lake Restoration Feasibility Study

Cedar Lake Restoration Feasibility Study

Location: Olathe, Kan.

Client: City of Olathe

Completion Date: 2009

Burns & McDonnell prepared a lake restoration feasibility study for the City of Olathe, Kan., on Cedar Lake, a former water supply reservoir. The study consisted of evaluating the physical, chemical and biological components of the lake to determine what would be required to restore the lake. It was determined that dredging would be necessary.

Upon completion of the evaluation, five dredging alternatives were developed. Two were determined viable: 1) Dredging using a treatment train system. 2) Dredging using a GeoTube dewater system. Two separate conceptual dredging designs and cost estimates were developed based on the two conceptual designs. The city preferred the GeoTube dewatering system, due the flexibility to land apply the dredging material, the ability to use the tubes in a phased approach, and the reduction of land use costs.

  • Bathymetric survey
  • Water and soil analysis
  • Conceptual dredging design
  • Cost analysis

Reservoir sedimentation is a growing national concern, with 200 of the nation's largest reservoirs now more than 40 years old and quickly approaching the end of their life expectancy. Sedimentation is of particular concern in the central part of the United States, where most reservoirs were constructed for the purposes of flood control, water supply, irrigation, water quality, recreation and, to a lesser extent, navigation. As sediment volume increases and water volume decreases, the intended functions of a reservoir can be adversely impacted. This is the problem facing Cedar Lake, which is one of the oldest lakes in Kansas.

Cedar Lake was completed in 1938 to provide drinking water for the City of Olathe, Kan. Specific information concerning its design life including sediment storage capacity was not available. Because Cedar Lake was no longer considered to be adequate as a water supply reservoir, in 1956 the city constructed Lake Olathe as the new drinking water supply lake. Cedar Lake was to be maintained as a supplemental source of drinking water.

However, since Cedar Lake continued to fill with sediment, it was determined not to be economically feasible to continue maintaining it as a supplemental drinking water supply reservoir. It has since transitioned primarily to water-based recreation and to some extent serves the purposes of flood control and protecting the quality of Olathe Lake.