Manton Heights Housing Complex Rain Garden

LID Type: Rain Garden
Use: Residential
Installer: Groundwork Providence
Designer/Developer: Gates, Leighton & Associates
Install Date: April 2011

Address: 10 Richland Street
Town: Providence
Zip Code: 02909
County: Providence

Kate Venturini
URI Outreach Center

The Manton Heights Housing Complex rain garden was constructed as a hands-on training exercise for Groundwork Providence’s Sustainable Urban Landscaping Job Training Program. The project was completed in collaboration with Gates, Leighton & Associates, a landscape architecture firm located in East Providence, David Renzi of Out in Front Horticulture (Exeter, RI), and instructors from the University of Rhode Island (URI) Outreach Center.

Amanda Sloan of Gates, Leighton & Associates designed the garden adhering strictly to the guidelines set forth in the new Rhode Island Stormwater Design and Installation Standards Manual, which was adopted January 1, 2011. As a result, stormwater runoff from approximately 2,500 square feet of impervious surface on the Manton Heights site is diverted from conventional storm drains into the newly constructed rain garden, where instead it may infiltrate and recharge the groundwater below.

The garden is situated in the rear corner of the complex, at the foot of a sloped, planted bank running along a concrete staircase leading from an apartment building down to a parking lot. Prior to the garden’s installation, the sloped bank could not handle a regular load of stormwater – runoff from a parking lot above resulted in erosion of the slope along with flooding and silt blowouts in the parking lot below, with the silt ultimately depositing in a storm drain.

A 2-foot wide grass infiltration strip along the garden edge where water enters and a flanking infiltration trench of pea gravel serve as a “treatment forebay” before water enters the garden bowl itself. On the garden edge closest to the parking lot, a curved berm was constructed to prevent the garden from overflowing. The garden was planted with native trees, shrubs, grasses, and herbaceous perennials that had been donated by both the Groden Center and Briden Nursery (Cranston, RI).

Subsequent visits to the garden months after the installation indicate that it is functioning well. Runoff is being captured and filtered with no overflow into the parking lot, and the grass and gravel infiltration forebay is structurally sound.

Address: 10 Richland Street, Providence, RI 02909