A method for comparative analysis of recovery potential in impaired waters restoration planning

Common decision support tools and a growing body of knowledge about ecological recovery can help inform and guide large state and federal restoration programs affecting thousands of impaired waters. Under the federal Clean Water Act (CWA), waters not meeting state Water Quality Standards due to impairment by pollutants are placed on the CWA Section 303(d) list, scheduled for Total Maximum Daily Load (TMDL) development, and ultimately restored. Tens of thousands of 303(d)-listed waters, many with completed TMDLs, represent a restoration workload of many years. State TMDL scheduling and implementation decisions influence the choice of waters and the sequence of restoration. Strategies that compare these waters' recovery potential could optimize the gain of ecological resources by restoring promising sites earlier. We explored ways for states to use recovery potential in restoration priority setting with landscape analysis methods, geographic data, and impaired waters monitoring data. From the literature and practice we identified measurable, recovery-relevant ecological, stressor, and social context metrics and developed a restorability screening approach adaptable to widely different environments and program goals. In this paper we describe the indicators, the methodology, and three statewide, recovery-based targeting and prioritization projects. We also call for refining the scientific basis for estimating recovery potential.