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 acres of land in the creekshed. Pioneer High School currently has no stormwater quantity control measures, so this project will provide the high school with needed detention and improve downstream water quality and quantity. It is estimated that 93 lbs of phosphorous per year per acre of the upstream drainage area will be removed from the creek as a result of the project. The detention system includes an underground storage chamber that allows for infiltration, porous pavement, swirl concentrators and bio infiltration. The resolution authorizes repayment of the low interest loans for this project from the Storm Water Fund (Fund 0069).
A formal petition from the City is required to move this project to construction. Allen Creek is an established Chapter 20 County Drain. Therefore, the work to construct the detention system and other control measures falls under the jurisdiction of the Washtenaw County Drain 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 $4,414,300.00, all of which has been approved for a low interest (2.5%) State Revolving Fund (SRF) loan to the County. In addition, the Washtenaw County Drain Commissioner has applied for a grant from the Michigan Department of Environmental Quality (MDEQ) grant for $750,000.00; if awarded, the cost of the loan and the City's proportionate share will be reduced by said amount. The City's apportionment of this drainage district is approximately 95.4% of the district. Therefore, the City's share will not exceed $4,211,242.00.
As the Drain Commissioner will be assessing the City over a maximum of 20 years for this project, the City will not have to expend the full cost of this project at the time of construction. Rather, the reimbursement of the Drain Commissioner will be paid over the financing period, with installments not to exceed $300,000.00 per year. The first payment is included in the approved Storm Water Fund budget for FY 09.
Staff
Prepared by: Molly Wade, Water Quality Manager
Reviewed by: Sue F. McCormick, Public Services Administrator
Approved by: Roger W. Fraser, City Administrator
Body
At a regularly scheduled meeting of the City Council of the City of Ann Arbor, County of Washtenaw, Michigan, held at the City Hall in the City on November 17, 2008, there were
PRESENT: Mayor Hieftje, Councilmember Rapundalo, Councilmember Greden, Councilmember Higgins, Councilmember Teall, Councilmember Anglin, Councilmember Briere, Councilmember Smith, Councilmember Derezinski, Councilmember Taylor, and Councilmember Hohnke, 11;
ABSENT: 0.
The following resolution as offered by Councilmember Briere and seconded by Councilmember Teall.
Whereas, There is a Total Maximum Daily Load (TMDL) for phosphorus and E. coli reduction within the Huron River;
Whereas, The Allen Creek Drainage District is within the area covered by the phosphorus and E. coli TMDLs;
Whereas, The Allens Creek Initiative has identified the construction of an underground detention system at the Pioneer High School property as the top priority project to improve downstream quality and quantity;
Whereas, On September 9, 2008, the Ann Arbor Public School Board approved the use of the Pioneer High School property to construct a stormwater detention system;
Whereas, The City Council intends to file with the Drain Commissioner for Washtenaw County a petition to clean out, relocate, widen, deepen, straighten, extend, tile, interconnect, or otherwise improve a portion of the county drain located at Pioneer High School, known as the Allen Creek Drain pursuant to Section 482 of Chapter 20 of the Drain Code of 1956 (MCL 280.482);
Whereas, It is the desire of the City Council to have the Mayor and Clerk sign and file the necessary petition with the Washtenaw County Drain Commissioner; and
Whereas, A suggested form of such petition is now presented to the City Council;
RESOLVED, The City Council hereby determines to proceed with the proposed drain project for the Allen Creek Drain Drainage District as more fully described in the petition attached hereto as Attachment 1;
RESOLVED, The Mayor and Clerk be hereby authorized and directed to execute such petition for and on behalf of the City and to file the same with the Drain Commissioner of the County of Washtenaw;
RESOLVED, The City Council hereby consents to the location of the proposed clean out, relocation, widening, deepening, straightening, extending, tiling, interconnecting or otherwise improving a portion of the Allen 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 $4,211,242.00 plus interest) will be paid in twenty annual installments not to exceed $300,000.00/annually from the Operations and Maintenance Budget of the Stormwater Fund (Fund 0069), beginning in FY 09.
A vote upon the foregoing resolution was taken and was as follows:
Roll call vote:
Ayes: Mayor Hieftje, Councilmember Rapundalo, Councilmember Greden, Councilmember Higgins, Councilmember Teall, Councilmember Anglin, Councilmember Briere, Councilmember Smith, Councilmember Derezinski, Councilmember Taylor, and Councilmember Hohnke, 11;
Nays: 0.
Absent: 0.
Abstain: 0.