Maps

Existing Use establishes protection for a waterbody on or after November 28, 1975 whether or not that use is included in the water quality standards (25 Pa. Code §93.1 and 40 CFR §131.3(e)). Existing Use is different from a Designated Use; Designated Use is defined for each waterbody or segment whether or not the use is being attained. Existing Use is the actual use the waterbody is attaining at the time of an evaluation. The Department maintains a publicly accessible list of surface water segments where data has been evaluated which indicates an existing use classification of a waterbody that is more protective than the designated use (including those segments which are HQ or EV). Only an existing use which is more stringent than the designated use in §§ 93.9a - 93.9z for a particular waterbody is placed on the existing use list. This GIS watershed layer (which is not part of the Water Quality Standards) is offered to provide a spatial representation of the Aquatic Life Use Tiers contained in the portion of the Pennsylvania Code referenced above. These spatial representations are intended to supplement the Water Quality Standards but should not be substituted for the official version of the standards found in the Pennsylvania Code.

Water quality criteria are used to protect designated water uses, such as fish and aquatic life, recreation, and water supply. Designated uses establish the reason for protection and the water quality criteria define the criteria required to protect that benchmark. Use designations and water quality criteria together, constitute Pennsylvania Water Quality Standards as defined in Title 25 Environmental Protection, Department of Environmental Protection, Chapter 93. This GIS watershed layer (which is not part of the Water Quality Standards) is offered to provide a spatial representation of the Aquatic Life Use Tiers contained in the portion of the Pennsylvania Code referenced above. These spatial representations are intended to supplement the Water Quality Standards but should not be substituted for the official version of the standards found in the Pennsylvania Code.

The Waterbody Inventory/Priority Waterbodies List (WI/PWL) is an inventory of the state's surface water quality. The dataset provides a summary of general water quality conditions, tracks the degree to which a water body supports its designated uses, and monitors progress toward the identification and resolution of water quality problems, pollutants, and sources. The category of No Known Impact represents 'segments where monitoring data and information indicate that there are no use restrictions or other water quality impacts/issues.'

Small, non-tidal watersheds with the largest population of rare, threatened and endangered aquatic animals.

Small, healthy non-tidal watersheds that are used for long term monitoring to detect changes from global climate change and from other natural phenomena.

Watersheds that support coldwater dependent species.

Large Watersheds that provide important spawning and nursery habitat for commercial and recreational anadromous fisheries.

Highest ranking (top 20th percentile) small watersheds important for protecting water quality based on biophysical characteristics.

Highest ranking small watersheds that support high quality coastal habitat, natural resources and critical fisheries spawning and nursery areas in tidal waters and near-shore areas.

This map represents a complete, aggregated layer of protected lands in the Chesapeake Bay Watershed and intersecting Counties as of 2011. It is a combination of multiple State, Federal and Non-Governmental Organization sources. Overlapping and duplicate areas have be deleted to address double counting.