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Products > Water Availability and Use > Ecological Flows

All Ecological Flow Products


thumbnail Online Screening Tool for New Water Withdrawals in Michigan –The State of Michigan ratified the Great Lakes-St. Lawrence River Basin Water Resources Compact on July 9, 2008, and under the Compact, agreed to develop implementation legislation to prevent adverse resource impacts of water withdrawals on the ecosystems and watersheds within the Basin. Through cooperative science projects, USGS, in cooperation with the State of Michigan and Michigan State University, provides science to support to the state in the development of an innovative water-withdrawal assessment process and on-line screening tool for new or increased water withdrawals (On-line screening tool). This process combines ungaged-flow estimation, a statewide ecological flow classification of streams, estimation of streamflow depletion by wells, and ecological-response curves describing the potential impact of water withdrawals on characteristic fish populations within a legislative and management framework.


thumbnail Environmental Flow Studies in the Shenandoah Valley of Virginia –USGS, in cooperation with the Central Shenandoah Valley Planning District Commission, the Northern Shenandoah Valley Regional Commission, and Virginia Commonwealth University, examined the instream flow needs of aquatic organisms of the South Fork and North Fork Rivers. Consistent model output and a range of scenarios are presented to Valley planners and water-resource managers regarding current and future water resources in the basin, the availability of water for fish habitat, recreation, and the potential effects of withdrawals and conservation measures on fish populations.  For example, a key finding from the recent South Fork study suggests that for normal or wet years, increased water withdrawals are not likely to correspond with extensive habitat loss for game fish or nongame fish. During drought years, however, a 20- to 50-percent increase in water withdrawals may result in below normal habitat availability for game fish throughout the river and nongame fish in the upper and middle sections of the river. These simulations of rare historic drought conditions, such as those observed in the Valley in 2002 serve as a baseline for development of ecological flow thresholds for drought planning.  (Studies available at: http://pubs.usgs.gov/sir/2012/5081 and http://pubs.usgs.gov/sir/2006/5025/.)


thumbnail Low Flow Management in northeast Kaua'I, Hawai'i –USGS, in cooperation with the State of Hawaiʻi Department of Hawaiian Home Lands, assessed the availability and distribution of natural low flow in Anahola Stream in northeast Kaua'i, Hawai'i, which supports agricultural, domestic, and cultural uses within its drainage basin.  Biological surveys were conducted as part of the study to determine the distribution of native and nonnative aquatic stream fauna. The report summarizes scenarios that describe (1) surface-water availability under regulated conditions of Anahola Stream if the upper and lower intakes are restored in the future; and (2) amount of flow available for agricultural use at the upper intake under a variety of potential instream-flow standards that may be established by the State of Hawaiʻi for the protection of instream uses. (Full report)


thumbnail Peak-Flow and Stream Ecology Management of the Cedar River, Washington –USGS, in cooperation with Seattle Public Utilities, assessed the linkages between high-flow events, geomorphic response, and effects on stream ecology in the gravel-bedded Cedar River in Washington. High flows can deleteriously affect salmon embryos incubating in the streambed gravels. Recorded accelerometer disturbances, combined with a two-dimensional hydrodynamic model, allowed the prediction of streambed disturbance at the burial depth of Chinook and sockeye salmon egg pockets for different peak discharges. Insight gained from these analyses led to the development of suggested monitoring metrics for an ongoing geomorphic monitoring program on the Cedar River. (Full report)


thumbnail New research on ecological flows in the Tennessee and Cumberland River Basins, TennesseeNew findings have been released, in cooperation and partnership with the Tennessee Wildlife Resources Agency, Tennessee Department of Environment and Conservation, The Nature Conservancy, and the Tennessee Valley Authority, that improve understanding of how alteration of streamflow characteristics affects ecological health of rivers and streams in Tennessee. Initial efforts are aimed at identifying critical streamflow characteristics and providing a set of statistical tools and analytical approaches for the prediction of these characteristics. Application of these tools will enhance understanding of how hydrologic alteration may change fish community structure in the Tennessee River basin.

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