By Paige Ahlborg
|Proposed rain garden site at Rosetown American Legion in Roseville|
Focusing on areas with large impervious surfaces as target areas for installing Best Management Practices (BMPs) to improve water quality is a goal of the Ramsey-Washington Metro Watershed District. In the past three years the District has been successful in implementing grant and cost share projects with churches to implement retrofit BMPs.
Our latest focus has turned to commercial properties, including strip malls and other retail centers. In 2014, the District received a Clean Water Legacy Fund Grant to assist in the site analysis process.
Identify Priority Sites
The project goal for the commercial site assessment was to identify the highest priority sites in sub watersheds with impaired or ‘at risk’ waters for retrofit BMPs that will assist the District in meeting stormwater volume and nutrient reduction goals.
|Paige Ahlborg, Watershed Project Manager,
conducting a site assessment
Potential retrofit sites were first identified using GIS data which resulted in a list of over 1,500 properties. To narrow the field, the project team developed a strategy to weigh each site based on criteria that included total acreage, percent impervious surfaces, proximity to water bodies and presence of existing BMPs. This resulted in 54 sites slated for site visits, further assessment and ranking.
|ArcGIS Collector Map|
Visit and Prioritize
The team visited these top sites and prioritized them, using grading criteria developed for this project. A letter grade A through F was applied to each of the potential BMP sites. The grade was based on a summary of observed site characteristics including stormwater quality benefit, estimated construction expense, and potential educational value. As a result of the site grading process, eight “A” properties and twelve “B” properties were identified. These sites became the basis for the site meetings with property owners.
The goal of the project was to meet with ten property owners and develop concept plans for BMPs on their properties. Out of the twenty A/B sites identified, the top sixteen candidates were contacted and ten meetings were held to inform and educate the property owners of the District’s overall goals, as well as to describe the potential partnership and installation of a BMP on their property. An important part of this project involved interaction with the commercial property owners to facilitate this collaboration and to lay the groundwork for the District to effectively work with commercial property owners into the future.
|BMP Retrofit Location Map|
As a direct result of this project, three commercial properties will have rain garden retrofits installed in 2015 and potentially six sites will move forward with rain garden retrofits in 2016 and 2017. The three to be constructed this year are Rosetown American Legion in Roseville, Taurus Manufacturing and Dey Enterprises in Vadnais Heights.
The District hopes to continue to implement grant projects like the ones described here in order to continue growing the public’s awareness of BMPs and work towards a greener, healthier watershed.