Title
Resolution to Petition the Washtenaw County Water Resources Commissioner to Design and Construct Stormwater Controls in the Allen Creek Drainage District in West Park to Improve Water Quality ($3,540,000.00 Project Amount; $3,401,940.00 City Share) (Roll Call Vote Required)
Memorandum
Attached for your approval is a resolution to petition the Washtenaw County Water Resources Commissioner (WCWRC) to undertake a project to design and construct stormwater controls in the Allen Creek Drainage District in West Park.
The Allen’s Creek Initiative identified construction of stormwater control measures in West Park a priority to improve water quality within the creekshed during storm events. The Allen’s Creek Initiative was launched in 2007 and is a collaborative effort with the WCWRC, the City of Ann Arbor, Ann Arbor Public Schools and the Allen’s Creek Advisory Committee. Its goal was to identify, prioritize and select stormwater management projects on public lands that would reduce flooding and improve water quality in Allen Creek.
Much of Allen Creek is contained in underground piping that carries stormwater runoff from the urban core of Ann Arbor. Nearly 44% of the land draining to the creek is impervious and, as a result, stormwater frequently enters the creek too quickly, causing localized flooding during rain events. These rain events also carry pollutants from impervious areas to the creek, lowering water quality. Allen Creek falls within the Total Maximum Daily Load (TMDL) area of the Huron River. The goal of the TMDL is to remove 50% of the phosphorus and E. coli from storm water.
West Park provides drainage for approximately 783 acres of land in the creekshed. West Park currently has no stormwater quality control measures, so this project will provide those areas with needed stormwater controls that will improve downstream water quality. It is estimated that 229 lbs of phosphorous per year from the upstream drainage area will be removed...
Click here for full text