Adopt Resolution #18-072 Accepting Feasibility Study and Ordering Plans and Specifications for COR Infiltration Basin Improvements, Improvement Project #18-09

The City made the decision to place their municipal wells in the western part of the City where development was expected to happen in the mid 1990's. The area around the wells was selected as the site of Ramsey Town Center (RTC) in the early 2000's and development began.The state required development of a well head protection plan for the wells in the late 2000's. This plan included delineation of a Drinking Water Supply Management Area (DWSMA) and 10 year capture zones for each well.  The DWSMA and 10 year capture zones cover most of the RTC properties. The City acquired the foreclosed RTC properties in 2009 and began marketing the properties as The COR.

The City is part of the Lower Rum River Watershed Management Organization (LRRWMO) which is tasked with maintaining water quality through regulating stormwater discharges. The LRRWMO Third Generation Plan was adopted in 2012. Their plans must be updated every 10 years just like the City Comprehensive Plan. The Third Generation plan required infiltration of the first one (1) inch of runoff from all impervious surfaces (roofs and paving) on new projects. The infiltration guidelines discourage or prohibit infiltration in wellhead protection areas. The Third Generation Plan has a provision that projects can pay into an infiltration mitigation fund if they cannot infiltrate on site.

Most of the COR area to be developed is in the area where infiltration is not permitted. All projects developed in the COR since 2015 have paid into the infiltration mitigation fund. LRRWMO permits were approved for these projects with the condition that the City develop an infiltration basin in an area where infiltration is permitted. The City was required to have the infiltration basin in place by July 1, 2018. Preparing a Feasibility Study is the first step to preparing plans for the infiltration basin to meet this goal.

The basin will be finished with native plants that can tolerate periodic inundation.  Topsoil will not be placed in the infiltration area because our specified topsoil is designed to retain water, not allow it to pass through.

The project will require acquisition of approximately 0.8 acres of easement and/or property from the adjacent land owner. Staff has started a conversation with this land owner regarding this acquisition, and will be prepared to discuss this in more detail at the time Council is asked to accept the Feasibility Study and authorize plans and specifications, which is tentatively scheduled for April.

The plans will include rough grading of the future east-west street connection between Rhinestone Street and Ramsey Boulevard.  Construction of the pavement section and storm sewer will be completed as a future improvement project.
 
The City Council approved preparation of a feasibility study at the March 27, 2018 meeting.  The feasibility study has been completed and is attached to this case.

Observations:
The feasibility study has determined that this improvement is necessary, cost effective and feasible as detailed in the attached report.

Alternatives:
Alternative #1 – Motion to adopt Resolution #18-072 accepting the Feasibility Study and ordering plans and specifications for COR Infiltration Improvements, Improvement Project #18-09.

Alternative #2 – Motion to deny adoption of Resolution #18-072 at this time.

 

The City has collected infiltration mitigation funds from all developments in the COR since 2015. These funds will pay approximately 1/4 of the cost of the project. The City will pay for the remainder of the project now and be reimbursed as future development occurs. The source will be the storm water fund.

The estimated cost for the improvements is $880,000, excluding easement/property acquisition costs, if required.

Staff recommends the City Council accepting the Feasibility Study and ordering plans and specifications for COR Infiltration Improvements, Improvement Project #18-09.

Motion to accept the attached Feasibility Study and order Plans and Specifications for the COR Infiltration Basin Improvement, Improvement Project #18-09.