A collaborative and adaptive process for developing environmental flow recommendations

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.

Macroinvertebrate community response to inter‐annual and regional river flow regime dynamics

“…Clausen and Biggs, 1997;Jowett and Duncan, 1990;Monk et al, 2006;Olden and Poff, 2003;Richter et al, 1998;Sheldon and Thoms, 2006). When combined with biological data, these hydrological descriptors can be used as a basis for the development of ecologically sustainable management strategies that balance anthropogenic demands on water resources against protecting, conserving and even enhancing, instream habitat and communities (Petts et al, 2006;Poff et al, 2003;Richter et al, 2006;Tharme, 2003).…”

Application of the physical habitat simulation for fish species to assess environmental flows in an Atlantic Forest Stream in South-eastern Brazil

“…Moreover, the establishment of e-flow regimes also should consider periods of high flow that adjust to natural variation, in order to remove sediments, shape the river channel, provide migration and spawning cues for some fish, and made available areas for species reproduction and feeding (Richter et al, 2006;Schwartz & Herricks, 2008). Furthermore, it will be fundamental to apply holistic approaches to maintain or partially restore important characteristics of the natural flow regime required to maintain the biophysical components and ecological processes of rivers, floodplains, aquifers and estuaries in this river basin (Arthington & Pusey, 2003;King & Brown, 2006;Poff et al, 2010).…”

River Hydrology, Flow Alteration, and Environmental Flow

“…Some address just parts or the river system, while others are more holistic (Tharme 2003;Acreman and Dunbar 2004). Currently, there exist at least 200 environmental flow methods classifiable in four major categories according to focus, complexity, and cost and time effectiveness: (1) hydrological methods, (2) hydraulic rating, (3) habitat simulation models, and (4) holistic methodologies (Dyson et al 2003;Tharme 2003;Arthington et al 2004;Richter et al 2006;King et al 2008).…”