West Hills Innovative Stormwater Demonstration
Final Report, Chapter 2: Identifying the Most Problematic Land Uses

Forest Heights is already a very green place with lots of trees. A mix of good regulation and “best practices” in the past protected its stream corridors… to a point. Unfortunately, sediment (which is just another word for dirt) and other pollutants from the property continue to impact water quality.

Historically, the lion’s share of this pollution has come from projects under construction, but over time, we have come to understand that pollution comes from all of our already constructed land surfaces in developed areas, including roofs, sidewalks, roads, driveways, and even lawns and gardens! The FHHOA hopes to implement practices in the common areas, but since sediment comes from everywhere (see chart), an ongoing, cooperative partnership with residents is needed. This will likely take years to fully implement.

Table 2-1: Soil exported from a variety of different land use covers, after construction is completed. Adapted from the “Pennsylvania Stormwater Best Management Practices Manual”, Table 8.3 and more recent data for some values was incorporated from the Center for Watershed Protection “Urban Stormwater Retrofit Practices, Appendices, 2007”

Table 2-1 summarizes the concentration of sediment that comes from typical landscapes after being constructed and put into use. This table is a powerful tool in helping to prioritize the kinds of areas that should be targeted for treatment. The top three sources of sediment are “Lawn”, “High Traffic Street/Highway””, “Grassed Athletic Field”. Since the FHHOA doesn’t have the second and third highest sources of sediment (the playing field at the school is artificial turf), the top three sediment sources at the FHHOA are “Lawn”, “High Traffic Parking Lot”, and “Medium Traffic Street”.

The model that was developed combines these sediment export values with surfaces that generate high levels of runoff to inform the final recommendations. Read more about the methodology in Appendix A.

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Updated 31 Jul 2014
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