Mill Creek Project – HDR Foundation

Mill Creek Project
Supported by a grant from the HDR Foundation

What we’re doing?

The Lower Merion Conservancy (LMC) is partnering with the Villanova Department of Geography and the Environment (GEV) to expand upon its historically recognized StreamWatch program in Mill Creek through the introduction of three permanent stream monitoring locations (see Map). Each of the three monitoring stations records measurements of stream flow as well as the conductivity and turbidity of the water at 15-minute intervals. This high-frequency, year-round sampling will allow us to answer questions such as how stormwater runoff is affecting the concentrations of road salt and sediment in Mill Creek. These measurements will also provide baseline data to measure water quality improvements in Mill Creek over time.

Over the 2016-2017 academic year, Villanova GEV students will collect actual measurements of dissolved salt and suspended sediments to compare with the monitoring station data in order to calculate how much salt and sediment is traveling down Mill Creek at any given data. In the interim, raw data downloaded monthly from the monitoring stations will be posted on-line in graphical form for public viewing through the links on this page.

Why is monitoring streamflow, water chemistry, and turbidity important?

Recently, the US Environmental Protection Agency established the use of total maximum daily loads (TMDLs) for watersheds as a way of combating excessive nutrient and sediment inputs from non-point sources, such as stormwater runoff. TMDLs are derived from nutrient and/or sediment thresholds above which the receiving surface water body (i.e., bay, lake, etc.) will experience negative impacts, such as algal blooms. A unique aspect of TMDLs is that they now expand the responsibility of contamination to all stakeholders within a watershed, and not just the previously regulated point sources (i.e., sewage treatment plants, manufacturers, etc.). This change in policy has brought about an urgency to understand the relative impact of all non-point sources in a watershed and how they may result from different land use practices (i.e, lawns, parking lots, etc.)

Why Mill Creek?

The Mill Creek watershed has been designated as “impaired” by the Pennsylvania Department of Environmental Protection and has been assigned TMDLs for both sediment and nutrients. In addition, the mouth of Mill Creek is located less than a mile upstream of the main drinking water intakes for the City of Philadelphia. Given the fact that a watershed is a sum of all its parts, lessons learned from Mill Creek could be expanded throughout other tributaries in the greater Schuylkill River watershed, thus benefiting the water supply for the greater Philadelphia area.

Want to get involved?

We are very interested in partnering with local schools in the area to expand on our monitoring of Mill Creek as well as sharing the monitoring data for classroom use. Please contact Chelsea Heck ( or Steven Goldsmith ( for more information.

Thanks to a generous grant from the HDR Foundation, the Conservancy was able to purchase all of the equipment necessary to support high-frequency, high-caliber data collection from Mill Creek. The HDR Foundation promotes the value of environmentally responsible practices and invests in community-led environmental restoration efforts that improve water quality, habitat and community green spaces.