Maps

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.

Over the past 10 years, the majority of nitrogen concentration trends are non-significant (28 sites), with 19 sites showing improving condition and only 1 site showing degrading conditions. 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 nitrogen concentrations in streams.

Changes in suspended sediment concentrations have been determined for the period 1985-2011 at 31 stream sites in the Chesapeake Bay watershed. Of these, 14 sites show trends that were not statistically significant, 9 sites show improving trends, and 8 sites show degrading trends.

Changes in phosphorus concentrations have been determined for the period 1985-2011 at 31 stream sites in the Chesapeake Bay watershed. Of these, the majority of the flow-adjusted trends were downward, with 22 sites showing decreasing trends, 4 sites showing increasing trends, and 5 sites showing trends that were not statistically significant.

Changes in nitrogen concentrations have been determined for the period 1985-2011 at 31 stream sites in the Chesapeake Bay watershed. Of these, the majority of the flow-adjusted trends were improving, with 21 sites having improving trends, 3 sites had degrading trends, and 7 sites the trends were not statistically significant.

Long-Term Flow-Adjusted Concentration Trends for Suspended Sediment for 31 Sites in the Chesapeake Bay Watershed, 1985-2010

Long-Term Flow-Adjusted Trends for Total Phosphorus for 31 Sites in the Chesapeake Bay Watershed, 1985-2010

Long-Term Flow-Adjusted Trends for Total Nitrogen for 31 Sites in the Chesapeake Bay Watershed, 1985-2010

This map is a key to monitoring stations used to depict flow-adjusted concentration data for nitrogen, phosphorus, and sediment.

This map shows long-term flow-adjusted trends for suspended sediment (32 sites in the Chesapeake Bay watershed) from 1985-2009.