COST EFFECTIVENESS AND INCREMENTAL COST ANALYSES FOR WATERSHED DECISION-MAKING: APPLICATION TO THE ELIZABETH RIVER, VIRGINIA, ENVIRONMENTAL RESTORATION

Authorized by Congress in 1995, the purpose of the Elizabeth River Environmental Restoration Study was to investigate the feasibility of addressing problems associated with ecosystem and environmental degradation in the highly urbanized 300-square mile Elizabeth River watershed in Hampton Roads, Virginia. The significance of the environmental, ecological, and cultural resources of the Elizabeth River watershed has been recognized both nationally and regionally by such entities as the Chesapeake Bay Program, the Library of Congress. Local Legacies Program, the Chesapeake Bay Agreement 2000, and the grassroots Elizabeth River Project organization. Early in the study process, the multi-agency, multi-stakeholder study team (including the US Army Corps of Engineers, the Commonwealth of Virginia, the cities of Chesapeake, Norfolk, Portsmouth, and Virginia Beach, the US Fish and Wildlife Service, local planning commissions, universities, and local citizens groups, among others), identified loss of wetlands and contaminated river bottom sediments as two of the greatest factors contributing to environmental degradation in the watershed.Specifically, the study team formulated and evaluated options to incrementally remediate contaminated sediments to levels protective of human and ecological health, and to maximize restoration of such wetlands functions as primary production, fish and wildlife habitat, water quality improvement, erosion buffer, flood buffer, and aesthetics. Data was collected to quantify the extent and level of contamination (e.g., using indices of biotic integrity, toxicity, histopathology, and sediment quality) of various sediment “hot spots” throughout the watershed. Various existing and former wetlands sites were also evaluated using both Habitat Evaluation Procedures and a wetlands functional assessment methodology to quantify the ecosystem outputs of the wetlands. For all of the sediment remediation and wetlands restoration options, the ecological or environmental outputs and associated monetary costs of all the potential alternative plans were evaluated through cost effectiveness and incremental cost analyses (CE/ICA). IWR-PLAN Decision Support software was used to conduct CE/ICA, identifying, first, plans that produce the greatest level of environmental output for a given level of financial investment, and secondly, plans that produce the greatest increases in environmental output for the least increases in cost.The CE/ICA results are used in conjunction with information regarding the significance of the environmental outputs, as well as acceptability, completeness, effectiveness, and efficiency criteria, to select a “National Ecosystem Restoration” (NER) plan. The NER plan that best contributes to the environmental restoration of the Elizabeth River watershed includes restoration of nine wetlands sites and medium level clean-up at one contaminated sediment site.