A collaborative and adaptive process for developing environmental flow recommendations

TLDR

River restoration projects increasingly aim to restore environmental flow regimes to improve ecosystem health, prompting planners to reserve flows for ecosystem support and necessitating scientifically credible estimates of environmental flow needs. The paper presents an adaptive, interdisciplinary, science‑based process for developing environmental flow recommendations. The process comprises five steps—orientation, literature review, workshop, trial implementation, and monitoring—designed for diverse water‑management activities and adaptable to available time and resources. The process produced monthly low‑flow, high‑flow pulse, and flood‑frequency recommendations, which were applied to the Savannah River and integrated into the Corps of Engineers’ basin plan, initiating adaptive management at Thurmond Dam. © 2006 John Wiley & Sons, Ltd.

Abstract

Abstract Many river restoration projects are focusing on restoring environmental flow regimes to improve ecosystem health in rivers that have been developed for water supply, hydropower generation, flood control, navigation, and other purposes. In efforts to prevent future ecological damage, water supply planners in some parts of the world are beginning to address the water needs of river ecosystems proactively by reserving some portion of river flows for ecosystem support. These restorative and protective actions require development of scientifically credible estimates of environmental flow needs. This paper describes an adaptive, inter‐disciplinary, science‐based process for developing environmental flow recommendations. It has been designed for use in a variety of water management activities, including flow restoration projects, and can be tailored according to available time and resources for determining environmental flow needs. The five‐step process includes: (1) an orientation meeting; (2) a literature review and summary of existing knowledge about flow‐dependent biota and ecological processes of concern; (3) a workshop to develop ecological objectives and initial flow recommendations, and identify key information gaps; (4) implementation of the flow recommendations on a trial basis to test hypotheses and reduce uncertainties; and (5) monitoring system response and conducting further research as warranted. A range of recommended flows are developed for the low flows in each month, high flow pulses throughout the year, and floods with targeted inter‐annual frequencies. We describe an application of this process to the Savannah River, in which the resultant flow recommendations were incorporated into a comprehensive river basin planning process conducted by the Corps of Engineers, and used to initiate the adaptive management of Thurmond Dam. Copyright © 2006 John Wiley & Sons, Ltd.