Title
Resolution to Petition the Washtenaw County Drain Commissioner to Design and Construct a Stormwater Detention System in the Allen Creek Drainage District on the Pioneer High School Grounds to Reduce Downstream Flooding and Improve Water Quality ($4,414,300.00 Project Amount; $4,211,242.00 City Share) (Roll Call Vote Required)
Memorandum
Attached for your approval is a resolution to petition the Washtenaw County Drain Commissioner (WCDC) to undertake a project to design and construct a stormwater detention system in the Allen Creek Drainage District on the Pioneer High School grounds. The Ann Arbor Public School Board approved the use of their land for this project at their September 9, 2008 meeting.
The Allens Creek Initiative identified construction of a detention system at Pioneer High School as the top priority to control water quantity and improve water quality within the creekshed during storm events. The Allens Creek Initiative was launched in 2007 and is a collaborative effort with the Washtenaw County Drain Commissioner, the City of Ann Arbor, Ann Arbor Public Schools and the Allens Creek Advisory Committee. Its goal was to identify, prioritize and select stormwater management projects 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.
The Pioneer High School property is located in the upstream area of Allen Creek and provides drainage for approximately 309 ac...
Click here for full text