Forecast-Based Operations of the Yuba and Feather River System Ben Tustison Water Resources Engineer MBK Engineers 2450 Alhambra Blvd., 2nd floor Sacramento, CA 95817 Tel: 916-456-4400 Fax: 916-456-0253 E-mail: [email protected] Web: www.mbkengineers.com BIOGRAPHICAL SKETCH Ben Tustison is a water resources engineer with MBK Engineers in Sacramento, California, where he has worked since June 2001. Most of his work has been with small and large-scale flood control projects and water supply modeling of the Sacramento/San Joaquin River System. Prior to coming to MBK, he performed research at the Saint Anthony Falls Laboratory in Minneapolis, Minnesota. He has published several papers on QPF verification with gage, radar, and satellite precipitation observations. He holds B.S. and M.S. degrees in Geological and Civil Engineering from the University of Minnesota. FORECASTFORECAST--BASEDBASED OPERATIONOPERATION OFOF THETHE YUBAYUBA ANDAND FEATHERFEATHER RIVERRIVER SYSTEMSYSTEM Ben Tustison MBK Engineers 2450 Alhambra Blvd., 2nd floor Sacramento, CA 95817 tel: (916)456-4400 fax: (916)456-0253 web: www.mbkengineers.com e-mail: [email protected] OVERVIEWOVERVIEW § What is Forecast-Based Operation (FBO)? § FBO Impacts § Yuba and Feather River System Description § Details of Forecast-Based Operation Study § Results of FBO Study § Conclusions § Future Developments WHATWHAT ISIS FBO?FBO? § Definition of Forecast-Based Operation (FBO): Flood control Operation of a reservoir by which releases are made Based on an inflow Forecast rather than actual reservoir inflow 72 inflow / forecasted inflow flow hours outflow inflow forecast magnitude initiating FBO time FBOFBO IMPACTSIMPACTS § Flood Control Benefits of FBO • Allows additional flood control space to be created, potentially providing increase in level of protection • Purely operational, requires no structural change § Additional Risk Due to FBO • If inflow forecast is overestimated, the foregone water supply may not be recovered SYSTEMSYSTEM DESCRIPTIONDESCRIPTION Oroville N Feather River New North Yuba Bullards River Bar Middle Yuba 180,000 cfs Yuba River River Yuba City / South Yuba Marysville 120,000/180,000 cfs River 300,000 cfs Shanghai Bend Travel Times Bear River 30 hrs 320,000 cfs 16 hrs STUDYSTUDY DETAILSDETAILS § Spreadsheet model with both New Bullards Bar and Oroville operated hourly § Oroville and New Bullards Bar operational flood regulations implemented, including: • Rate of change criteria • Downstream flow limitations • Emergency spillway release diagrams (ESRD) • 1-in-100-Year to 1-in-500-Year events studied in 25-Year increments STUDYSTUDY DETAILSDETAILS § Inflow forecast lead time • 72 hours § FBO initiation trigger • 200,000 cfs Oroville inflow forecast • Expected to trigger once every 15 years § Potential increase in flood space • Oroville 100,000 acre-feet (13% increase) • NBB 50,000 acre-feet (30% increase) STUDYSTUDY RESULTSRESULTS Existing and FBO Operation of Oroville for 200-yr Flood event Flood Flow FBO Space Reduction Initiated Gained Flood Space Lost STUDYSTUDY RESULTSRESULTS Existing and FBO Operation of New Bullards Bar for 200-yr Flood event Flood Flood FBO Space Space Initiated Gained Lost STUDYSTUDY RESULTSRESULTS Existing and FBO Operation of New Bullards Bar for 200-yr Flood event New Bullards Bar 23 kcfs Additional Outlet Capacity Flood Flood Space FBO Space Lost Flow Initiated Gained Reduction STUDYSTUDY RESULTSRESULTS New Bullards Bar / Yuba River Maximum Flows (kcfs) NBB Outflow Yuba River at Marysville 100-yr 200-yr 500-yr 100-yr 200-yr 500-yr Existing 50 104 151 162 236 328 FBO 50 104 151 162 236 328 NBB + 23 kcfs 50 94 141 162 199 318 + FBO Oroville / Feather River Maximum Flows (kcfs) Oroville Outflow Feather River at Shanghai Bend 100-yr 200-yr 500-yr 100-yr 200-yr 500-yr Existing 150 169 324 279 378 553 FBO 150 160 314 279 370 546 NBB + 23 kcfs 150 160 314 279 358 546 + FBO CONCLUSIONSCONCLUSIONS § Oroville Dam / Feather River • FBO reduces peak Oroville outflow (3-7%) and flow at Shanghai Bend (2-5%) for the events studied • A significant portion of space gained by just after the activation of FBO is later lost due to limited outflow capacity CONCLUSIONSCONCLUSIONS § New Bullards Bar / Yuba River • FBO has minimal reductions in New Bullards Bar outflow (<3%) and Yuba River at Marysville flows (<2%) due to insufficient outlet capacity • Adding 23 kcfs of additional outlet capacity, reduces peak New Bullards outflow (up to 40%) and the peak Yuba River flow at Marysville (up to 20%) for the events studied FUTUREFUTURE DEVELOPMENTSDEVELOPMENTS § Development of a real-time reservoir release forecast model for the Yuba and Feather River system § Continue to evaluate FBO in combination with complimentary operational or structural flood control enhancements to the Yuba and Feather River system, e.g., • Levee Setback • Reservoir Surcharge • Outlet Capacity Increase.