HECRes Sim Enhancements Better Tools to Simulate the
HEC-Res. Sim Enhancements Better Tools to Simulate the Operation of California Reservoirs Joan Klipsch CWEMF Annual Meeting February 2007 Hydrologic Engineering Center
Outline • HEC-Res. Sim Basics – – Development Objectives The System Schematic Rule-Base Operations Definition New Features in Version 3. 0 • The Yuba-Feather F-CO Study – – Participants Objective MOA Requested Enhancements for Version 3. 1 Hydrologic Engineering Center
Res. Sim Development Goals • Represent the physical system as realistically as possible. • Reproduce the decision making process that reservoir operators use to set releases. • Support Multi-Purpose Operation Schemes – Represent both Flood Control Constraints & Conservation Goals – Support low flow & drought operation – Support environmental restoration investigations Hydrologic Engineering Center
The Physical System • Graphical System Schematic – – – Reservoirs Reaches Junctions Diversions Diverted Outlets • Hierarchical Multiple Outlet Structure – – Controlled and Uncontrolled Outlets Power Plants Pumps Outlet Groups Hydrologic Engineering Center
System Schematic Hydrologic Engineering Center
Rule-Based Reservoir Operations • Guide-Curve – The seasonally-variable Desired Pool Elevation – Basic Guide Curve Operation: “Release or store to get back to guide curve. ” • Zones – Zones partition reservoir storage among different purposes. – A prioritized set of rules within each zone limits or overrides basic guide curve operation. Hydrologic Engineering Center
Rule-Based Reservoir Operations • Rules A rule is an objective for, or constraint on, the operation of a reservoir or system of reservoirs. Rule Types: – Flexible Local & Downstream Flow Objectives – Release or Pool Elevation Rates of Change – Emergency Gate Regulation & Induced Surcharge – Local and System Hydropower Requirements – Tandem Operation – Pump-back Schedule – User-scripted rules Hydrologic Engineering Center
Zone-Based Prioritized Rule Set Hydrologic Engineering Center
1. Determine the… Allowable Range of Releases – – Physical Capacity defines the initial range Rules narrow the range 2. Determine the… Desired Guide Curve Release – How much the reservoir should store or release to get back to guide curve in this timestep Hydrologic Engineering Center Allowable range of releases (cfs) Basic Decision Logic 15, 000 10, 000 5, 000 0 1 2 3 0: Physical Capacity 1: IROC - 3000 cfs 2: Max Release - 10, 000 cfs 3: Min Release – 700 cfs Allowable Range: 700 -8000 cfs
Basic Decision Logic, Cont’d. 3. Decide ! ? Is the Desired Guide. Curve release within the allowable range? Yes Make the Desired GC release No Make the allowable release that is closest to the Desired GC release. Hydrologic Engineering Center
Other Important Operations Features • Tandem and Parallel System Operations – With variable storage balancing definition • • Conditional (If-then-else) Rule Activation Release Allocation – Outlet Prioritization User Scripted Rules & State Variables Outlet Outages & Capacity Overrides Hydrologic Engineering Center
Tandem & Parallel System Operations • Tandem – El Vado to Abiquiu – Abiquiu to Cochiti • Parallel – Cochiti & Jemez Hydrologic Engineering Center
System Balance Definition Hydrologic Engineering Center
Conditional Rule Use Atwood & Leesville “watch” Dover – Not true Tandem Hydrologic Engineering Center
Conditional Rule Use If-then-else blocks Hydrologic Engineering Center
Release Allocation • To provide control over how the releases are allocated to the available outlets • Two methods – Balanced • Even Balance (default) • Un-even Balance – e. g. 60 -40 split – Sequential Hydrologic Engineering Center
Storage Integration Scheme • Solution to the problem that occurs when a reservoir has: – Small storage – Large outlet capacity – More inflow than can be stored during a time-step Hydrologic Engineering Center
Trials • Simulation ‘copies’ of an alternative • Provides extended “what-if” analysis Hydrologic Engineering Center
New Development – FY 07 • R&D Funded – Routing Enhancement for Downstream Ops – Tailwater-Dependent Outlet Capacity – Technical Reference Manual • Project Funded – LCRA • Projected Pool Operation – Yuba-Feather F-CO Study… Hydrologic Engineering Center
Forecast-Coordinated Operations • Yuba-Feather Watershed – Oroville - Operated by CA DWR – New Bullards Bar - Operated by Yuba County Water Agency • Study Objectives – Develop a way to coordinate flood control releases from the two reservoirs, at the same time maintaining channel flow at or below the channel capacity at Marysville Hydrologic Engineering Center
Forecast-Coordinated Operations • Study Team – Yuba County Water Agency – California Dept. of Water Resources – NWS CA-NV River Forecasting Center – Advisory: Sacramento District, USACE • Funding – (new) Prop 13 Grant Hydrologic Engineering Center
Yuba-Feather F-CO • SPK Water Management was consulted on existing models for the basin. • Study team chose Res. Sim for the operations modeling tool. • SPK & Study Team identified some modifications that would be needed to effectively represent the watershed. Hydrologic Engineering Center
Identified Enhancements • Phase 1 – Downstream operation must respect rate-ofchange constraints – Improve Induced Surcharge operation algorithm to remove oscillations – Induced Surcharge function inadequate to represent ESRD operations. • Provide option to enter ESRD curves directly • Add a “Hold the Gate” option for falling pool operation Hydrologic Engineering Center
Identified Enhancements • Phase 1, cont’d. – Add a variable contingency factor to the downstream control rule to represent uncertainty in the inflow forecast – Add a inflow factor editor to facilitate development of “what-if” inflow scenarios • Phase 2 – Add ensemble management to alternative development – Add ability to impact operations based on probability… Hydrologic Engineering Center
MOA with HEC • Yuba County Water Agency – 1+ year in development – Effort failed over liability issues • NWS – 3 -6 months in development – Success! Hydrologic Engineering Center
Additional Requirements • NWS-RFS integration – Hot-start Feature – Headless Operation – Port to Linux Hydrologic Engineering Center
Downstream Ops & Rate-of-Change - Current Hydrologic Engineering Center
Downstream Ops & Rate-of-Change - New Hydrologic Engineering Center
New - Contingency Factor • Effective space at the downstream control location is computed as the difference between the downstream limit modified by the contingency percentage and the cumulative local flow. • For a downstream maximum flow rule, the downstream limit is multiplied by (1 – contingency percentage/100), resulting in a reduced maximum limit. Hydrologic Engineering Center
Contingency Factor Hydrologic Engineering Center
New - Inflow Multipliers Hydrologic Engineering Center
More Info… • Version 3. 0, Release March 2007 !!! • HEC’s Web Site: www. hec. usace. army. mil • HEC’s Res. Sim Point of Contact: Joan D. Klipsch Hydrologic Engineering Center
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