Watershed-wide Priority Agricultural Watershed Rankings 2021

<p style="background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;"><strong>Open the Data Source:</strong><a style="border:0px solid currentcolor; box-sizing:border-box; color:rgb(0, 97, 155); font-family:inherit; line-height:1.5; text-decoration:none;" target="_blank" href="https://gis.chesapeakebay.net/ags/rest/services/PriorityAgriculturalWatersheds/PAW_WW_2021/MapServer"> </a><a target="_blank" href="https://gis.chesapeakebay.net/ags/rest/services/PriorityAgriculturalWatersheds/PAW_WW_2021/MapServer/0">https://gis.chesapeakebay.net/ags/rest/services/PriorityAgriculturalWatersheds/PAW_WW_2021/MapServer/0</a></p><p style="background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;">In 2010, the U.S. Environmental Protection Agency (EPA), U.S. Geological Survey (USGS) and regional Land Grant Universities developed Priority Agriculture Watershed (PAW) maps to inform where to focus federal funding for agricultural conservation practices to reduce the greatest nitrogen and phosphorus loads to the tidal Chesapeake Bay. Since then, Priority Agriculture Watershed maps have been used to target implementation funds including EPA Region 3 Chesapeake Bay Implementation, Regulatory and Accountability Program grants, National Fish and Wildlife Foundation (NFWF) Chesapeake Bay Stewardship grants and U.S. Department of Agriculture Natural Resource Conservation Service (NRCS) Farm Bill programs. The NRCS targeting effort was the precursor to USDA creating the Chesapeake Bay Watershed Initiative which created dedicated Farm Bill funding for the watershed.</p><p style="background-color:rgb(255, 255, 255); border:0px solid currentcolor; box-sizing:border-box; color:rgb(74, 74, 74); font-family:&quot;Avenir Next&quot;, Avenir, &quot;Helvetica Neue&quot;, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 1rem; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;">The data layers used to create the original 2009 maps were updated by a 2018 release of the USGS SPARROW model (<a style="border:0px solid currentcolor; box-sizing:border-box; color:rgb(0, 97, 155); font-family:inherit; line-height:1.5; text-decoration:none;" target="_blank" href="https://doi.org/10.3133/sir20185051">https://doi.org/10.3133/sir20185051</a>) for delivered loads of nitrogen or phosphorus from agricultural sources, agricultural land uses and Clean Water Act Section 303(d) 2016 reports used to emphasize local waters impaired from potential agriculture-related sources. This approach integrates modeling (SPARROW) and monitoring (303d) data to prioritize USGS 12-digit hydrologic units (HUCs) for Chesapeake Bay and local water quality benefits. The PAW analysis ranked HUCs across the Chesapeake Bay watershed in terms of their contribution of nitrogen (N) and phosphorus (P) pollutants to Chesapeake Bay streams. HUCs that fell above a threshold to be considered an Agricultural HUC (AgHUC) were ranked across the watershed based on SPARROW modeled stream pollutant movement between catchments, or Delivered Loading Rate (DLR), for N and for P separately. These rankings were performed across the watershed as well as across each state to enable more flexible mapping comparisons, and especially to facilitate interactive web applications for the public to use to examine results. In addition, the fraction of all SPARROW-derived local catchment 303(d) assessed streams that were in SPARROW-derived agricultural catchments, and that carried 303(d) Agriculture-related pollutants within the same HUC, was produced in this analysis. Percent rankings for the fractional data was not created as it was deemed inappropriate due to the meaningful coarseness of this statistic. This dataset represents the watershed-wide rankings. State-specific rankings can be found here: <a target="_blank" href="https://gis.chesapeakebay.net/ags/rest/services/PriorityAgriculturalWatersheds/PAW_WW_2021/MapServer/0">https://gis.chesapeakebay.net/ags/rest/services/PriorityAgriculturalWatersheds/PAW_WW_2021/MapServer/0</a></p>