Maps

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.

Average yields for total sediment (TS) were estimated for the last five years at 65 sites and classified into thirds as high, medium, and low. While the distribution was spatially variable, there were some general patterns in location. Generally, spatial patterns not very discernible for sediment except for higher yields in the middle of the watershed, areas where total nitrogen and total phosphorus yields are also highest. The lowest yields are generally in the western areas of the Bay watershed, an area dominated by forests and on the Eastern Shore of Maryland and Delaware.

Average yields for total phosphorus (TP) were estimated for the last five years at 65 sites and classified into thirds as high, medium, and low. While the distribution was spatially variable, there were some general patterns in location. Generally, higher yields for TP are dominant in the middle of the watershed, areas that also coincide with large urban and agricultural land uses. The lowest yields are generally in the western areas of the Bay watershed, an area dominated by forests.

Average yields for total nitrogen (TN) were estimated for the last five years at 65 sites and classified into thirds as high, medium, and low. While the distribution was spatially variable, there were some general patterns in location. Generally, higher yields for TN are dominant in the middle of the watershed, areas that also coincide with large urban and agricultural land uses. The lowest yields are generally in the Virginia watersheds.

Over the past 10 years, the majority of sediment concentration trends are non-significant monitoring at sites within the Bay watershed with many sites showing degrading condition and only a few are improving. The trend results indicate that at some monitored locations, short-term trends indicate that management actions, such as efforts to curb erosion and runoff have reduced concentrations of sediment. While these reductions provide evidence of improving conditions in some upstream areas, additional reductions will be needed to have healthier streams and meet water-quality goals for the Bay.

Over the past 10 years, the majority of phosphorus concentration trends are non-significant monitoring at sites within the Bay watershed with many sites showing improving condition and only a few are degrading. The trend results indicate that in many locations, management actions, such as improved wastewater treatment and nonpoint-source pollution controls (i.e. urban stormwater runoff and agricultural runoff controls), have reduced phosphorus concentrations in streams.