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<br /> <br />L <br /> <br />Stream Gaging <br />Gate and Turbine Calibration <br /> <br /> <br />-..... <br /> <br />"t.....14OttIIID <br />--- <br /> <br />Project Tasks: <br />- Developed stage discharge relationships for several streams. <br />- Calibrate and verify discharge rating curves for the gates and turbines for <br />several dams and hydroelectric facililies. <br /> <br />Project Description: <br />As a part of a Federal Energy Regulatory Commission (FERC) re-licensing process, <br />Polaris Group established rating curves (elevation vs discharge) for numerous stream <br />gaging locations. These gaging stations were installed to monilor flows into and from <br />reservoirs. The rating curves required flow measurements for a range of discharges. <br />Standard U.S. Geological Survey methods were typically used. <br /> <br />Polaris Group streamlined the process in a few ways. Gaging trips were coordinated <br />between several sites to minimize field time. Where possible, a range of measurements <br />were made at one time by regulating the flow upstream with the reservoir gates. At other <br />locations, a weir was placed in the flow which initially blocked the discharge. <br />Measurements were taken just after the flow started over the weir and proceeded until <br />after the flow reached a stable level. This provided a continuous record of flows from zero <br />to the level of flow in the stream on that day. <br /> <br />The FERC re-licensing process also required verification of the gate and turbine discharge <br />curves at hydroelectric facilities. Often the flow configurations made measurements <br />difficult. Polaris Group calibrated ten different facililies using several different methods <br />ranging from standard USGS in-stream flow measurements to acoustic doppler current <br />profiling. Where possible, gate calibration efforts were coordinated with downstream <br />gaging station measurements to complete two project requirements at one time. <br />