The MCWD is undertaking a long term project with the objective of improving the water quality in the Minneapolis Chain of Lakes. The project specifically focuses on stormwater management in the Twin Lakes Subwatershed to improve the water quality of Cedar Lake which is the receiving body of water.

The MCWD has worked closely with the City of St. Louis Park , the City of Minneapolis and the Minneapolis Park and Recreation Board (MPRB) to incorporate the watershed improvements into the Clean Water Partnership Grant that has been awarded to the Minneapolis Park and Recreation Board. A cooperative agreement between the parties, including Hennepin County, coordinates responsibilities for the overall improvements over the next six years.

Water quality improvement efforts have been focused on the Twin Lakes Subwatershed and Cedar Lake mainly because of public cooperation and the desire to improve water quality by the local communities. According to a 1993 Diagnostic Study, Twin Lakes Subwatershed contributes over 50% of the flow and over 60% of the phosphorus loading into Cedar Lake. Specific projects identified to improve the water quality of the runoff entering Twin Lakes and Cedar Lake include:

1. Excavation of a 1.3 acre wet detention basin upstream of Twin Lakes within Twin Lakes Park; the purpose of the wet detention basin is to improve stormwater quality prior to discharge into Twin Lakes, to provide additional storage capacity for runoff in an area in St. Louis Park that is prone to occasional high water, and to restore part of a former wetland that has been filled.

2. Dredging of Twin Lake to an average depth of 5.5 feet to increase the hydraulic residence time thereby increasing sediment and nutrient removal prior to discharging to Cedar Lake; the existing Twin Lake outlet will also be lowered by one foot to enable adequate hydraulic gradient for the Twin Lakes Park improvements, to provide additional lake storage capacity for stormwater, and to increase the flow capacity of the existing outlet to help alleviate local flooding problems.

3. Excavation of a 4.6 acre wet detention basin/wetland system at the Cedar Meadows area near the southwest corner of Cedar Lake located sough of Cedar Shore Drive between France Avenue and Cedar Lake Parkway; this segment of the project includes diversion of a portion of the Twin Lakes outflow and local drainage to the Cedar Meadows area to further treat stormwater runoff entering Cedar Lake

The projects identified in numbers 1 & 2 above are currently in process. Implementation of the vegetation restoration plan for Twin Lakes was implemented in April and May. The Cedar Meadows project will begin in May and should be concluded by the fall of 1996.

Chain of Lakes Project Specifications:

• Location: Twin Lake/Cedar Lake, Minneapolis, Minnesota
• Completed: 1996
• Contractor: Veit & Company, Inc.
• Engineer: Wenck Associates, Inc.
• Cost: $1.4 million
• Funding: MCWD Ad Valorem Tax
• Twin Lakes Outlet: Lowered 1 foot
• Twin Lakes Deepening: 81,700 cubic yards excavated; 3.6 acre feet
• Cedar Meadows Pond/Wetland: 49,000 cubic yards excavated; 4.4 acres; 11.2 acre feet
• Storm Pipe Diversion: 2,000 lineal feet
• Subwatershed Area Served: 1,700 acres