Hydroelectric Project Stream & Real-Time Flow Monitoring

Aug. 19, 2002
SUTRON PROVIDES REAL-TIME FLOW MONITORING FOR PACIFICORP PacifiCorp will use Sutron Corporation's monitoring system to bring real-time flow data to the North Umpqua Hydroelectric Project. The North Umpqua Hydroelectric Project, FERC Project No. 1927, located on the west side of the central Cascade Mountains, consists of eight powerhouses, eight dams, and 44 miles of waterway (canals and flumes) along the North Umpqua River, Clearwater River, and Fish Creek. The combined rated capacity of the project is 185,500 kW. All Project plants are operated from the Toketee Control Center in Toketee Village near the Toketee and Fish Creek power plants. REQUIREMENTS In 2000, PacifiCorp met with Oregon Water Resources Department (OWRD) representatives at the Toketee Control Center to review PacifiCorp's schedule for bringing the North Umpqua Project into compliance with operating licenses that specify maximum diversion from each natural stream as well as minimum flows to be maintained in bypass reaches (natural streams) below project diversions. The resulting agreement stipulated installation of a gauging system to account for all project diversions and bypass flows. Discharge data from the canal gauging system and penstock flowmeters was to be reported to the District 15 Watermaster's Office in Roseburg, Oregon, on a daily basis. Flow information from bypass reaches will be reported daily beginning in 2002. The resulting project has two phases. Phase I provides for monitoring flows in canals (by datalogger) and penstocks (by ultrasonic flowmeters). Reports will be generated by operators who acquire data from the logger network and the penstock flowmeters. Phase 2, completed by October 31st of 2002, will add monitoring of bypass reaches and bring all of the data to the Toketee Control Center by means of a radio network. A computer system will allow operators to monitor flows in real-time and will automate report generation for OWRD. OWRD requirements: · Gauges will meet applicable United States Geological Survey (USGS) standards. · Rating tables for each gauge will be developed from current meter measurements over the range of expected canal flows. · Each rating will be verified annually to ensure accuracy. · Discharge data from the canal gauging system and penstock flowmeters will be reported to the District 15 Watermaster daily beginning in 2001. · Flow information from bypass reach USGS gauges will also be reported daily beginning in 2002. THE PROBLEM Because the area is mountainous with canal and river sites scattered over a 100 square miles, flow monitoring for North Umpqua presents challenges. Bypass reaches are in areas difficult to access, even on foot. Sites are often surrounded by tall trees, inhibiting communications and preventing use of solar panels for power. Access is primarily via dirt roads, barely passable in bad weather. Visiting each site daily requires heavy manpower (about 4 hours for a complete circuit). A water right or flow violation could go undetected for days. Viewing flow conditions in real-time is critical. THE SOLUTION--PHASE 1 Monitoring canal and river flows requires sophisticated expertise so PacifiCorp asked the U.S. Geological Survey to recommend a vendor. Sutron Corporation, a designer/manufacturer/installer of turnkey remote monitoring systems, was recommended. Sutron and PacifiCorp agreed to focus on canal sites in 2001 (Phase I) and complete the entire system by October of 2002. ODWR Phase I requirements will be met by placing permanent gauging stations near the downstream ends of major canals, using data loggers (without telemetry) that read flow directly by determining the relationship between flow depth and discharge rate and that store flow data. Real-time flow data requires a communications network. PacifiCorp has in place a variety of hard-wire and fiber optic links and has conducted experiments with line-of-site radio. PacifiCorp's access rights to an existing radio repeater site at Cinnamon Butte to the east of the project area will be an integral part of the solution. A complete radio path survey to facilitate design of the communications network for Phase 2 was completed in September, 2001. THE SOLUTION--PHASE 2 The Phase 1 monitoring system was in place by October 31, 2001 and the communications path survey to determine the exact combination of radios, repeaters, and other links needed to bring data back to the Control Center is finished. Next, the final communications system including data loggers and communications for the bypass reach sites will be implemented. The penstock flow meters will also be integrated into the telemetry network. When the entire computer system and software have been incorporated, operators will access a computer that stores canal and stream gauge ratings which are easily updated if changes are indicated by the stream gauging program. Ratings will be used in real-time to convert the telemetered stream and canal stages to flow. Values of the stage readings and the flows will be stored in a relational database that limits storage time for telemetered stage values and computed flows to 6 months. There will also be a process that automatically generates OWRD flow reports containing tables showing site-specific stage and flow measurements at a mutually-agreed-upon time of day and that stores this data on the system hard drive. A graphical man-machine interface (MMI) will aid operators in station setup and interpreting data. Trained personnel will use the MMI to change station characteristics as well as add or remove stations. The primary operator display will resemble a spreadsheet that contains a list of system gauging points and the current stage and flow. The display will update in real time. The table will update every 15 minutes (interval set by agreement with OWRD). Stations whose report times are more than 20 minutes old will be marked by yellowed time panels. Stations whose report times are more than 1 hour and 10 minutes old will be marked by red time panels. Yellow and red marked time panels alert the operator to any problems with telemetry. The table will also provide water right and low flow alerts. When flow exceeds the water right for the site, the flow value will be changed to blinking red and the amount of the alert will be presented in a separate "alert" window at the bottom of the table. Similarly, the system will warn if the flow drops below the specified minimum. The design will allow for multiple alerts (alerts at more than one site.) SUMMARY AND CONCLUSIONS PacifiCorp's real-time flow monitoring network will allow project operators to view the flow in system canals, bypass reaches and penstocks in real time as well as alert them when any violation of minimum flow requirements or water rights takes place. The system will use line-of-sight radio, fiber optic, and hard-wire communications technologies, data loggers, streamgaging stations, and ultrasonic flowmeters. It will save about four person-hours per day and greatly shorten response time to any flow change situation.