Watershed Resource Document for the CESR Report

This document examines the watershed system’s response to the Chesapeake Bay Program’s efforts to achieve the nutrient and sediment reduction goals thought necessary to achieve water quality standards. We focus on response gaps and uncertainties about how the watershed system has responded to management efforts meant to reduce nitrogen (N), phosphorus (P), and sediment loads reaching the Chesapeake Bay. Our discussion focuses primarily on the management of agricultural and urban nonpoint source pollution. Significant resources have been devoted to controlling both agricultural and urban nonpoint source pollution, but these efforts have not yet generated the expected system response and associated water quality improvements. Based on a synthesis of watershed response studies, we identify a number of possible reasons for the system response gap and discuss possible management actions to further pollution reduction efforts and improve system response.

We conclude that while there is substantial agreement on several major causes for the system response gaps, adequate remedies are confronted with uncertainties and/or difficult trade-offs. Wider best management practice (BMP) implementation/adoption (as is commonly acknowledged) can help to achieve reduction goals along with programmatic changes to improve the effectiveness of management actions. Improving system response to management actions will be challenging given the uncertainties associated with how the physical system responds to different management actions (BMPs) as well as how people manage nutrients and respond to policies designed to reduce pollution. Enhanced adaptive management approaches could be developed. Multiple opportunities to test, learn, and adapt to uncertainties associated with management could be evaluated. Additionally, the Chesapeake Bay Program (CBP) could make greater use of evaluation tools to systematically identify and evaluate key uncertainties when designing and implementing active adaptive management to address pollution.