Watershed Conservation


The Lower Merion Conservancy has been monitoring local watersheds since the Conservancy was formed in 1995, continuing the work Art Wolfe started in the 1970s. The StreamWatch program utilizes staff and volunteer monitoring to assess the conditions of our streams.

Delaware River Watershed Initiative

Since 2013, the Conservancy has been a partner in the William Penn Foundation’s Delaware River Watershed Initiative (DRWI), a regional effort led by more that 50 conservation groups working to improve water quality in the Delaware River Basin.

Through the DRWI, the Conservancy is currently working with the Borough of Narberth to install green, sustainable infrastructure along Windsor Avenue to help manage some of the stormwater in the area. The project will produce a vegetated swale to treat stormwater before it reaches the stream and to reduce the quantity of water sent into the stream during storm events. Previous Conservancy projects include stream bank restorations in Ashbridge Park, West Mill Creek Park, Shortridge Park, and Narbrook Park in addition to a demonstration rain garden in Rolling Hill Park next to our office. Since large portions of the land in Lower Merion are developed and privately owned, the Conservancy has also worked with property owners to manage stormwater on individual properties through the Conservancy’s Environmental House Call program.

In developed areas, impervious surfaces such as roads, sidewalks, and buildings prevent stormwater from percolating into the ground and cause stormwater to accumulate and flow away. Municipalities are organized so that stormwater is quickly sent down gutters, along sidewalks and streets, into storm inlets, and through pipes before being discharged in or near a stream. Although stormwater moves quickly as it is forced toward streams, it can pick up a variety of pollutants along the way. These pollutants, which include pesticides and fertilizer from lawns, petroleum products from cars, and rock salt from sidewalks and roads, contaminate the drinking water supply and are harmful to the stream ecosystem. Additionally, stormwater runoff can cause property damage through soil erosion and flooding. Proactive measures such as rain gardens allow water to infiltrate the ground, naturally treating the water and reducing the quantity of stormwater runoff simultaneously.