Suspended-sediment transport and water management, Jemez Canyon Dam, New Mexico, 1948–2018

First posted November 8, 2022 For additional information, contact: Director, New Mexico Water Science CenterU.S. Geological Survey6700 Edith Blvd. NEAlbuquerque, NM 87113 Construction and operation of dams provide sources clean drinking water, support large-scale irrigation, generate hydroelectricity, control floods, improve river navigation. Yet these benefits are not without cost. Dams affect the natural flow regime, downstream sediment fluxes, riverine riparian ecosystems. The Jemez Canyon Dam in was constructed 1953 by U.S. Army Corps Engineers with authorizations for flood retention. managers dam use various operational techniques to restore peak streamflow, management, altered ecosystem processes, while maintaining authorized purposes dam. This study focuses on four distinct reservoir management periods implemented at Dam: (1) predam (pre-1953), (2) a seasonal 24-hour hold pool (1953–79), (3) permanent (1979–2001), (4) dry (2001–18).Results this indicate successful reduction instantaneous streamflow events following construction dam, specifically documented 1958 2013. During second water period, moderate retention (also defined as trap efficiency, which is percentage incoming sediments trapped within during given time) occurred (between 41.0 67.0 percent were retained). third period between 61.2 99.8 retained. fourth (2001–18), least 1,909 acre-feet accumulated remobilized. estimated efficiency −37.2 percent, indicating that more being removed from Reservoir than deposited. These remobilized supplemented delivery River middle Rio Grande. current (2022) allows when flooding concern still providing needed.Suspended-sediment particle size data potential coarsening suspended likely resulting erosion coarse bed deposited reservoir. Suspended-sediment first finer mobilized monsoon season snowmelt. Also, suspended-sediment concentrations post-hold higher Seasonal variations concentration may help make decisions increasing understanding size, concentration, variation year. seasonality transport can also vary, depending only but precipitation. maximum annual loads all three categories analyzed study: snowmelt, monsoon, remainder indicates that, addition variability mechanisms load guide optimal operations