Type: Capital Project Grant
MWMO Funding: $350,000 Grant; $33,250 Feasibility Study
An MWMO grant will help the expanding NorthPoint Health and Wellness Center manage stormwater through biofiltration at the site’s surface and on-site stormwater treatment and detention in underground stormwater facilities with graywater storage for reuse (toilet and urinal flushing and exterior irrigation).
NorthPoint Health and Wellness Center is a multi-specialty medical, dental, and behavioral health center and human services agency. NorthPoint’s expansion and renovation is part of a significant campus redevelopment that includes three quadrants at the intersection of Penn and Plymouth Avenues in North Minneapolis.. The redevelopment has been in the making for more than 10 years, with a focus on “Partnering to Create a Healthier Community.” Expansion components include the construction of additions to the north and south of the existing building, new paved parking lots, and new sidewalks. The campus expansion is providing an opportunity to improve outdoor public spaces that integrate stormwater management in an innovative way.
NorthPoint is administered through a partnership between Hennepin County and a community board of directors. Hennepin County applied for an MWMO Capital Project Grant in April 2018. In order to determine the potential of stormwater management practices on the NorthPoint campus, the project’s design team worked through a stormwater feasibility study to evaluate above-and-beyond stormwater management opportunities for the project.
Clay soils on site make infiltration difficult, so the design focuses on filtering stormwater runoff instead. Modular subsurface flow wetland systems (MSFWS) will be constructed on the north and south ends for biofiltration of stormwater runoff. These pre-engineered systems include filtration cartridges for pretreatment, a biofiltration chamber with sorptive media and a layer of plant establishment media, a discharge chamber with an orifice control structure to control flow, and native plants. A raingarden will treat stormwater from a new paved parking area and pervious turfgrass area. These stormwater practices will demonstrate how water flows through the site and soften the urban character of the property with native vegetation.
Stormwater will be collected and stored on-site after the underground treatment. It will be used to reduce the site’s potable water usage within the building for toilets and urinals as well as for exterior irrigation. A southwest underground detention chamber will be used for outdoor irrigation reuse, supplemented by potable water in times of drought. A northeast detention chamber will be used for reuse in the interior of the building for toilets and urinals; this chamber includes a UV filter, piping, and associated systems. The underground chambers will provide rate control (i.e., slow the rate at which runoff leaves the site) for all of the existing building, the additions, and the new parking lots. The modular wetlands will provide water quality treatment from the same areas. Interpretive signage is planned to illustrate how stormwater is managed and reused onsite. Interpretive signage will be provided for the community illustrating how stormwater is managed and reused onsite and sharing the importance of water management in healthy communities.