Title
Resolution to Petition the Washtenaw County Water Resources Commissioner to Establish Huron River Green Infrastructure Drainage District for the City of Ann Arbor 2013 Tree Planting Project (Total Cost: $316,000.00; City’s Apportionment: $316,000.00)
Memorandum
Attached for your approval is a resolution to petition the Washtenaw County Water Resources Commissioner (WCWRC) to create a new City-wide Drainage District for the 2013 Street Tree Planting Project. These improvements will reduce the amount of stormwater entering the City's stormwater piping network and reduce contaminant loading to the downstream creeks and the Huron River. The proposed improvements will improve water quality and reducing localized flooding in the project areas.
Nearly 36% of the land draining to the Huron River and its tributaries is impervious, and as a result, stormwater frequently enters the river too quickly, causing localized and regional flooding during certain rain events. These rain events also carry pollutants from impervious areas to the creeks and ultimately the Huron River, reducing water quality. The City falls within area of the Huron River that is subject to the Total Maximum Daily Load (TMDL) for phosphorus and E. coli from stormwater. In addition, there are several creeks that have a creek-specific TMDL for Biota, which is attributed to unstable flow regimes, reduced bank stability, bank erosion, sedimentation and reduced stream quality due to excessive runoff/washout throughout the highly urbanized watershed. The metric used for addressing the TMDL is the amount of Total Suspended Solids (TSS) found within the creek habitat profile. This project will reduce the amount of soil that is carried into the creeks and river through erosion, and thus will reduce the TSS.
Since the project’s focus is on water quality improvement, it is eligible for low-interest State Revolving Fund (SRF) loan funding. This project has been included by the State of Michigan on...
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