Multipurpose Reservoirs and Reservoir Systems David Rosenberg CEE 6490 – Integrated River Basin / Watershed Planning & Management

Learning Objectives Diagram multi-purpose operations for a single reservoir Describe rules of thumb for drawdown and refill of reservoirs in series Compare rules of thumb for reservoirs in series and in parallel Illustrate use of rules in real reservoir systems Integrate rules into reservoir simulation models Mokelumne River Calaveras River Mokelumne and Calaveras Rivers, CA (Google Earth) CEE 6490

Multi-purpose Reservoir Operations Partition reservoir storage into “pools” Each pool has a separate purpose Release (or avoid releasing) water to reach the “guide curve” Dead/Inactive pool (no release) Buffer pool (min. in-stream flow releases) Conservation pool (release to meet water supply / hydropower delivery targets) Flood pool (release to empty, but don’t flood downstream areas) Surcharge pool (emergency spillway releases) Top of dam Guide Curve CEE 6490

Storage in thousand acre-feet Seasonal guide-curve 1,000 900 800 700 600 500 400 300 250 Storage in thousand acre-feet Contours are preceding 60-day basin-mean precip. (% of normal annual precip.) Release all excess storage above line as rapidly as possible, subject to: Do not exceed 50,000 cfs or maximum rate of inflow for flood event Do not exceed 150,000 cfs at any time Flows in a downstream damage reach do not exceed 180,000 cfs (HEC, 1976) CEE 6490

Comparing Operations Objectives Purpose Single Reservoir Reservoir System Water Supply Keep reservoir full; avoid spills; meet demands Avoid system spills* Flood Control Keep reservoir empty; avoid damaging releases Avoid damaging releases* Energy Storage Keep reservoir full + high head Max. total energy stored at end of refill season* Hydropower Production Keep reservoir full; meet energy demands Max. value of energy production* Recreation - Pool Keep reservoir full Equalize marginal rec. benefits of additional water *Releases to achieve objective depend on spatial configuration CEE 6490

Rules of Thumb Rules differ for different Reservoirs Reservoirs Water uses Spatial configurations inflow release/spill Reservoirs in Series: inflow release/spill Reservoirs in Parallel: CEE 6490

Operations Rules for Reservoirs in Series Purpose Refill Period Drawdown Period Water Supply Fill upper reservoirs first Empty lower reservoirs first Flood Control Energy Storage Hydropower Production Maximize storage in reservoirs with greatest energy production potential Recreation Equalize marginal recreational improvement of additional storage among reservoirs CEE 6490

Operations Rules for Reservoirs in Parallel Purpose Refill Period Drawdown Period Water Supply Equalize probability of seasonal spill among reservoirs Equalize probability of emptying among reservoirs Flood Control Leave more storage space in reservoirs subject to flooding NA Energy Storage Equalize expected value (EV) of seasonal energy spill among reservoirs For the last time-step, equalize EV of refill season energy spill among reservoirs Hydropower Production Maximize storage in reservoirs with greatest energy production potential Recreation Equalize marginal recreation improvement of additional storage among reservoirs

Illustrations and applications Feather and Yuba Rivers, CA (Rosenberg, 2003)

The Basins 2 parallel reservoirs 4.8 MAF storage (90% of mean annual flow) Drains 4,100 mi2 within larger 27,000 mi2 of Sacramento River Basin 3rd Marysville reservoir authorized, but never built Flood protection, Water supply, Hydropower, Recreation, In-stream flows

Feather and Yuba Rivers, CA Schematic CEE 6490

Feather and Yuba Rivers, CA Analysis Method Build Reservoir Simulation Models HEC-ResSim for flood operations Synthetic storms, various return periods, hourly time-step HEC-5 for water supply, hydropower and in-stream flow requirements Period-of-record of inflows, monthly time-step Specify performance objectives (more next slide) Simulate project alternatives Base case (existing) Storage reallocations (raise and lower guide curves) Re-operate for lower downstream flood flow requirements Select preferable alternative(s) CEE 6490

Feather and Yuba Rivers, CA Performance Indicators Flow criteria met at… Oroville (150,000 cfs), New Bullard’s Bar (50,000 cfs) Yuba City, Marysville (180,000 cfs) Feather + Yuba Confluence (300,000 cfs) Expected Annual Flood Damage ($) Simulate for likely (little water) and unlikely events (lots of water) Calculate damage for each event based on flows at downstream impact areas (HEC-FIA) Weight by event likelihood and damage amount Annualize to $ amount people pay every year Reliability, Vulnerability, and Resilience to meet water demand (%) CEE 6490

Relative Expected Annual Damages for Oroville & New Bullard’s Bar Storage Reallocations

Relative Expected Annual Damage for Reservoir Re-Operations Alternatives

Feather and Yuba Rivers, CA Primary Findings Storage reallocations have small influence on EAD Lowering flow objective to 270,000 cfs at Feather-Yuba confluence is most promising re-operation alternative Up to 200 TAF storage in Oroville serves little additional flood protection purpose Oroville reallocations have greater EAD reduction benefit than New Bullard’s Bar reallocations EAD extremely sensitive to flow at Marysville, Natomas, and levee failure stage at Natomas (Rosenberg, 2003) CEE 6490

Integrating concepts into reservoir simulation models

Reservoir Simulation Modeling Data Requirements For WEAP, HEC-ResSim, HEC-5, Oasis, RiverWare, etc. Time-series of inflows Spatial configuration of inflows Routing between model nodes Reservoir locations and Physical data: pool elevation-storage-area curves, evaporation and leak rates Dam outlets: elevation-release capacity curves Operations Zones: elevations Release rules and prioritization in each zone CEE 6490

Reservoir Simulation Modeling Computational Requirements Time step Method to calculate change in storage Finite difference Modified Puls (level pool) Are inflows, releases, etc. at beginning of time step or averaged over the time step? Routing Simple (constant discharge-storage; velocity-based) Muskingum (variable discharge-storage; attenuation) Hydraulic (unsteady flows, variable storage; wave and out-of-bank flow) CEE 6490

Reservoir Simulation Modeling Performance Measures Delivery-reliability Firm yield Max (or min) reservoir storage level Max (or min) flows at a particular location Hydropower generated Costs of shortages Economic revenues from (b) or (e) Vulnerability Resiliency And many, many others CEE 6490

Bear River Canal Company Above Cutler Cutler Bear River Canal Company New Cache Example 1. What features must you add to your ILO-3 model to represent this reservoir system? Box Elder County Bird Refuge Reservoir, proposed Reservoir, existing Urban Use Ag. Use CEE 6930 Wetland

References Bower, B. T., Hufschmidt, M. M., and Reedy, W. W. (1966). "Operating procedures: their role in the design of water-resource systems by simulation analysis." Design of Water Resource Systems, A. Maass and e. al, eds., Harvard University Press, 443-458. Hashimoto, T., Stedinger, J. R., and Loucks, D. P. (1982). "Reliability, Resiliency, and Vulnerability Criteria for Water Resource System Performance Evaluation." Water Resources Research, 18(1), 14-20. Hirsch, R. M., Cohon, J. L., and ReVelle, C. S. (1977). "Gains from joint operation of multiple reservoir systems." Water Resources Research, 13(2), 239-245. Labadie, J. W. (2004). "Optimal Operation of Multireservoir Systems: State-of-the-Art Review." Journal of Water Resources Planning and Management, 130(2), 93-111, http://dx.doi.org/10.1061/(ASCE)0733-9496(2004)130:2(93). Lund, J. R. (2000). "Derived power production and energy drawdown rules for reservoir." Journal of Water Resources Planning and Management-Asce, 126(2), 108-111, http://dx.doi.org/10.1061/(ASCE)0733-9496(2000)126:2(108). Lund, J. R., and Ferreira, I. (1996). "Operating Rule Optimization for Missouri River Reservoir System." Journal of Water Resources Planning and Management, 122(4), 287-295, http://dx.doi.org/10.1061/(ASCE)0733-9496(1996)122:4(287). CEE 6490

References (cont.) Lund, J. R., and Guzman, J. (1999). "Derived Operating Rules for Reservoirs in Series or in Parallel." Journal of Water Resources Planning and Management, 125(3), 143-153, http://dx.doi.org/10.1061/(ASCE)0733-9496(1999)125:3(143). Palmer, R. N., Smith, J. A., Cohon, J. L., and ReVelle, C. S. (1982). "Reservoir management in Potomac River Basin." Journal of Water Resources Planning and Management, 108(1), 47-66. Paredes, J., and Lund, J. R. (2006). "Refill and drawdown rules for parallel reservoirs: Quantity and quality." Water Resources Management, 20(3), 359-376, http://www.springerlink.com/content/d5654k8832pq50n4/?p=3d20773edd0c4a3eab8fea7681218e51&pi=1. Rosenberg, D. E. (2003). "Simulating Cooperative Flood and Water Supply Operations for two Parallel Reservoirs on the Feather and Yuba Rivers, CA," Masters Thesis, University of California, Davis, Davis, California, http://cee.engr.ucdavis.edu/faculty/lund/students/DavidRosenbergMS.pdf. Wurbs, R. A. (1993). "Reservoir System Simulation and Optimization Models." Water Resources Planning and Management, 119(4), 455-472, http://dx.doi.org/10.1061/(ASCE)0733-9496(1993)119:4(455). Yeh, W. W. G. (1985). "Reservoir Management and Operations Models: A State of the Art Review." Water Resources Research, 21(12), 1797-1818. CEE 6490