Title
Resolution to Approve an Agreement with the Washtenaw County Water Resources Commissioner to Evaluate and Identify Opportunities for Stormwater Improvements in the Churchill Downs & Lansdowne Areas of the Malletts Creek Drainage District (Total Cost: $200,000.00)
Memorandum
Attached for your approval is a resolution to enter into an agreement with the Washtenaw County Water Resources Commissioner (WCWRC) to undertake a project to evaluate and identify opportunities for conveyance and stormwater improvements in a portion of the Malletts Creek Drainage District, specifically the Churchill Downs and Lansdowne sub-creekshed drainage areas bounded by Ann Arbor-Saline Road, I-94 and Scio Church Road.
This proposed resolution is in answer to a previous Council Resolution R-12-373 on August 9, 2012 that directed staff to "Negotiate Agreement with the Washtenaw County Water Resources Commissioner to Evaluate and Identify Opportunities for Stormwater Improvements in the Churchill Downs & Lansdowne Areas of the Malletts Creek Drainage District."
Much of Malletts Creek is contained in underground piping that carries stormwater runoff from the urbanized areas of Ann Arbor. Nearly 37% 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. Malletts Creek falls within the area of the Huron River watershed that has a Total Maximum Daily Load (TMDL) requirement for phosphorus and E. coli from stormwater set by the Michigan Department of Environmental Quality (MDEQ). In addition, Malletts Creek has 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 Malletts Creek Restoration Project (2000) and the Malletts Creek Management Plan (2007) both identify construction of stormwater control measures within the creekshed as a high priority to control water quantity and improve water quality within the creekshed during storm events. These endeavors were a collaborative effort involving the Washtenaw County Water Resources Commissioner, the City of Ann Arbor, Pittsfield Township, the Malletts Creek Association, and the Malletts Creek Coordinating Committee. Goals include the identification, prioritization and selection of stormwater management projects that would reduce flooding and improve water quality in Malletts Creek.
On March 15, 2012 a large storm event resulted in surface ponding and street flooding in the southwest area of the City, particularly in portions of the Churchill Downs and Lansdowne subdivisions, which are within the Malletts Creek Drainage District. It is the City's and WCWRC's intent to identify opportunities for stormwater conveyance and stormwater quality improvement in this sub-creekshed drainage area. Potential opportunities may include but are not limited to detention, pipe upsizing, and green infrastructure (low impact development) to improve overland flow issues beyond the delineated floodplain in the upper reach of the Northwest Branch of Malletts Creek.
Malletts Creek is an established Chapter 20 County Drain. Therefore, any work to study and evaluate the County drainage system falls under the jurisdiction of the Washtenaw County Water Resources Commissioner. As an established drain, the costs of the project are assessed to the governmental entities within the drainage district area. The total cost of this project is estimated at $200,000.00. The funding for this project will be allocated from surplus drain funds, currently held with the Washtenaw County Water Resources Commissioner's Office.
Staff
Prepared by: Jennifer Lawson, Water Quality Manager
Reviewed by: Craig Hupy, Interim Public Services Administrator
Approved by: Steven Powers, City Administrator
Body
Whereas, There is a Total Maximum Daily Load (TMDL) for phosphorus and E. coli reduction within the Huron River;
Whereas, Malletts Creek Drainage District is within the area covered by the phosphorus and E. coli TMDLs;
Whereas, There is a Total Maximum Daily Load (TMDL) for biota within Malletts Creek;
Whereas, The Malletts Creek Restoration Project (2000) and the Malletts Creek Management Plan (2007) have identified the construction of stormwater controls within the creekshed as a high priority to control water quantity and improve water quality during storm events;
Whereas, On March 15, 2012 a large storm event resulted in surface ponding and street flooding in the area of the Malletts Creek Drainage District bounded by Ann Arbor-Saline Road upstream to I-94 and Scio Church Road;
Whereas, The City Council intends to enter into an Agreement with the Washtenaw County Water Resources Commissioner to evaluate and identify opportunities for conveyance and storm water improvements in the Malletts Creek Drain Drainage District in the Churchill Downs and Lansdowne sub-watershed areas that may be necessary or appropriate to provide, improve and restore storm water management and water quality protection functions within the Drainage District;
Whereas, It is the desire of the City Council to have the City Administrator sign and file the necessary agreement with the Washtenaw County Water Resources Commissioner; and
Whereas, A suggested form of such agreement is now presented to the City Council;
RESOLVED, The City Council hereby determines to proceed with the proposed drain project for the Malletts Creek Drain Drainage District as more fully described in the agreement attached hereto as Attachment 1;
RESOLVED, The City Administrator be hereby authorized and directed to execute such agreement for and on behalf of the City and to file the same with the Water Resources Commissioner of the County of Washtenaw;
RESOLVED, The City Council hereby consents to the location of the proposed project to evaluate and identify opportunities for conveyance and storm water improvements in the Churchill Downs & Lansdowne sub-watershed drainage areas portion of the Malletts Creek Drain within the limits of the City and the assessment of a portion of the cost of such improvements, so located, against the City; and
RESOLVED, That the assessment (approximately $200,000.00) will be allocated from surplus drain funds, held with the Washtenaw County Water Resources Commissioner's Office.