Click here to download a PDF of the Drinking Water Source Prioritization Map

Drinking Water Source Prioritization

The Philadelphia Water Department developed a model to identify areas of the watershed most important for drinking water source protection.  The model ranks all lands (on a scale from 1 to 10) that are not already developed or protected for their importance to protecting clean surface and ground water.  High ranking lands (shown in dark blue) are found throughout the Schuylkill Watershed, but the largest concentrations are located in the northeast quadrant of Berks County and the Pickering Creek Watershed in northeastern Chester County.

Nine layers with differing weights contribute to Philadelphia Water Department Drinking Water Source Protection Map:

• Forested Lands  (Weighted 10:  coniferous forest, deciduous forest and mixed forest categories from 2000 land cover data set)
• Headwaters  (Weighted 8:  A 200 foot buffer around all stream segments from National Hydrologic Database where stream order is 1)
• Reservoir Watersheds (Weighted 8:  Drainage of all drinking water reservoirs in the Schuylkill watershed)
• Exceptional Value Streams (Weighted 8:  Data set includes the watershed of all streams designated by PADEP as EV)
• Cold Water Fisheries (Weighted 8:  Data set includes 100 foot buffers beside all streams designated by PADEP as CWF)
• Source Water Assessment Zone A (Weighted 2.5 per zone:  Layer identifies areas wherere 1, 2, 3, or 4, Zone A’s are located.  Each layer is scored 2.5 so that when, for example, 3 Zone A’s overlap the score is 7.5)
• Groundwater Recharge Areas  (Weighted 8:  All A, B or AB soils in watershed)
• Drinking Water Wells (Weighted 8:  Data includes the surface watersheds of wells that serve >3300 customers delineated and provided by the PA_DEP.  Wells that did not have the delineation performed were assigned a 0.5 mile radius protection area around the location.
• Agricultural Lands (Weighted 4:  Where 2000 land cover is row crop, hay pasture, etc)