In 2005, Montgomery County Conservation District was awarded Growing Greener funding to implement a stormwater best management practices demonstration site on the headwaters to the Little Neshaminy Creek in Montgomery Township.

Montgomery Township is a suburban landscape in Montgomery County with high impervious cover. In 2000, the Township was mapped with approximately 40 percent impervious, up from only 4 percent in 1970.

The Growing Greener funding was awarded to retrofit a stormwater basin at the Mary Mother of Redeemer Church and School. The 30 acre facility has many existing natural features including; wetlands, a pond, and 500’ of a headwater stream tributary to the Little Neshaminy Creek.

The stormwater retrofit included removing a concrete low flow channel, modifying the outlet structure to provide extended detention, installing a sediment forebay to filter stormwater runoff, and naturalizing the basin. Upon removal of the low flow channel, a water quality berm was installed to maximize the flow path in the basin. The elevated berm directed stormwater through the basin, allowing it to meander within the basin before reaching the outlet structure.

The sediment forebay is a holding area where the stormwater enters the basin. It is a depressed area lined with larger rock which filters sediment and particulates from the stormwater as it enters the basin. At the outlet structure, the existing orifice was covered with a steel plate, and a new smaller orifice was installed one foot higher.

This provides extended detention and enabled the basin to support wetland vegetation.

Following completion of the basin modifications, students and parishioners of the Church and School planted native vegetation in the basin.

In addition to retrofitting the stormwater basin, the Growing Greener grant project helped to leverage additional funding for the project.

A TreeVitalize Watershed grant was awarded to plant 203 trees, and 342 shrubs to increase canopy cover, create wildlife habitat, and buffer the headwaters stream. The grant also funded 150 live stakes to enhance biodiversity in the wetlands.

A donation was made by a local company, Rohm and Haas, to purchase monitoring equipment for the students to study water quality in the stream and wetlands, and also to monitor the quality of the runoff at the inflow and outflow of the stormwater basin. We applied to Stroud Water Research Center through a Consortium for Scientific Assistance to Watersheds (C-SAW) grant to assist with establishing lesson plans, and instructing the teachers on how to use the monitoring equipment.

As part of our educational outreach efforts we held two workshops. An initial workshop was held in February 2006 as a kick-off event at the beginning of the project. There was a check presentation from DEP representatives and Sen. Greenleaf (R-Montgomery). Presenters at the workshop introduced topics such as the benefits of riparian buffer, stormwater retrofits, and the goals of the grant project. The workshop was attended by parishioners, students and parents, and interested local residents.

A second workshop was held in March 2008. At the second workshop we presented information on the completed project. We illustrated the before and after of the best management practices, the benefits of the project, and also presented information on long term operation and maintenance of basin retrofits, and riparian buffer.

Now, almost two years after the project was completed, the students and parishioners still continue to embrace the project and it’s environmental benefits. The Church’s Ecology Council maintains the best management practices, and the riparian buffer plantings. There is a walking path through the buffer that allows users to enjoy the solitude of this newly created habitat.

The project was recently awarded the 2009 Pennsylvania Horticultural Society’s Community Greening award which will be presented at an award reception in November, 2009.

Susan Harris, Watershed Specialist, Montgomery County Conservation District, can be contacted by sending email to: sharris@montgomeryconservation.org.