1. Modeling Flood Control Flexibility using the GENESYS Hydro Model Kyle Martin Mainstem Hydrologist Columbia River Inter- Tribal Fish Commission Portland, Oregon

2. Introduction http://www.nwppc.org/return_toc.htmA natural river reservoir operation promotes environmental conditions that are in harmony with the salmon’s biological timing. (Return of the River…Independent Science Group, 1996, http://www.nwppc.org/return_toc.htm ) Altered flood control and earlier reservoir refill can achieve a more natural flow regime.

3. Natural Hydrograph Concept Natural flow regimes enhance salmon survival with: increased turbidity, decreased travel time, increased habitat, higher river and estuary productivity.Natural flow regimes enhance salmon survival with: increased turbidity, decreased travel time, increased habitat, higher river and estuary productivity. More water is shifted from winter to late spring. Outflows modeled at minimum through May.More water is shifted from winter to late spring. Outflows modeled at minimum through May. Altered Flood Control uses less drafts during late winter and early spring. Strategy takes advantage of expected global warming.Altered Flood Control uses less drafts during late winter and early spring. Strategy takes advantage of expected global warming.

4. GENESYS Hydro-generation model This NPPC model uses monthly time steps.This NPPC model uses monthly time steps. Flow operations are specified at all PNW dams.Flow operations are specified at all PNW dams. Model runs sequentially from dam-to-dam.Model runs sequentially from dam-to-dam. Record spans Water Years 1929 - 1978.Record spans Water Years 1929 - 1978. Output: flow, pool elevations, generation.Output: flow, pool elevations, generation. New encoded storage Rule Curves can alter flood control operations.New encoded storage Rule Curves can alter flood control operations.

5. GENESYS Energy Analyses, Economics Multi-Dam Stand-Alone (Hydro-Sim model) PLANT File: Physical Characteristics-- Min/Max flow, FB vs. Storage Tail-Water vs. Discharge PERIOD File: Rule Curves OPERATIONS Files: Flow Limits, Spill, Storage Limits “Operation-Exception” Program Control Files-- Post-Processing GENESYS Multi-Dam Program Control Files-- Pre-Processing Graphical Displays: Outflow, Pool Elevations, Storage Tabular Reports and Data Files 50 years historical, observed data Proportional draft, PNCA specified Prioritized operating parameters Draft specific reservoirs, if desired

6. Altered Flood Control Global warming will reduce winter snow packs. Spring flood control drafts can be reduced.Global warming will reduce winter snow packs. Spring flood control drafts can be reduced. Reservoir refill probability increases.Reservoir refill probability increases. As reservoirs fill by May 31, excess inflow is passed and generates a higher seasonal peak.As reservoirs fill by May 31, excess inflow is passed and generates a higher seasonal peak. Altered flood control reclaims 5.55 MaF at Grand Coulee, 2.7 MaF at Dworshak, & 0.35 MaF at Brownlee (total: 8.6 MaF).Altered flood control reclaims 5.55 MaF at Grand Coulee, 2.7 MaF at Dworshak, & 0.35 MaF at Brownlee (total: 8.6 MaF). Advanced river forecasting tools (eg, UW-DHSV or NWSRFS) can reduce premature FC drafts.Advanced river forecasting tools (eg, UW-DHSV or NWSRFS) can reduce premature FC drafts.

7. Results of Natural River plan using GENESYS model Average (50-year) June peak at The Dalles is 375 kcfs. Current operational peak is 280 kcfs. High water year peak is 445 kcfs (21 years). Low water year peak is 245 kcfs (11 years).Average (50-year) June peak at The Dalles is 375 kcfs. Current operational peak is 280 kcfs. High water year peak is 445 kcfs (21 years). Low water year peak is 245 kcfs (11 years). Summer flows will increase by 18%. Winter flows may decrease by 20%.Summer flows will increase by 18%. Winter flows may decrease by 20%. Flood control maxima averages 1540 feet at Dworshak, 2055 feet at Brownlee, and 1265 feet at Grand Coulee.Flood control maxima averages 1540 feet at Dworshak, 2055 feet at Brownlee, and 1265 feet at Grand Coulee.

11. Benefits to Northwest Salmon Enhanced ecosystem health and diversity. Resident fish populations enjoy more habitat.Enhanced ecosystem health and diversity. Resident fish populations enjoy more habitat. Speed juvenile migrants to the estuary.Speed juvenile migrants to the estuary. Transport more woody and organic debris.Transport more woody and organic debris. Less predation. Cooler passage water.Less predation. Cooler passage water. Increase estuary plume--critical habitat.Increase estuary plume--critical habitat. Provide adequate flow for returning adults. Currently, flows are low in September.Provide adequate flow for returning adults. Currently, flows are low in September.

12. How a Natural River plan may Impact the Pacific Northwest More salmon return to spawn while Columbia Tribal treaties are honored.More salmon return to spawn while Columbia Tribal treaties are honored. Flood risk to Portland is 18% (versus 10%). Top 5 years average to 550 kcfs flood flow. A 600 kcfs flood flow gives 10% risk versus 6%.Flood risk to Portland is 18% (versus 10%). Top 5 years average to 550 kcfs flood flow. A 600 kcfs flood flow gives 10% risk versus 6%. Spring flood risk mitigated by global warming.Spring flood risk mitigated by global warming. Less winter generation will be offset by higher summer generation (June-September).Less winter generation will be offset by higher summer generation (June-September).

14. Summary Altered flood control can reclaim 8.6 MaF of storage to benefit salmon resources while restoring the Columbia and Snake rivers back to a natural peaking hydrograph. River and estuary habitat would improve.Altered flood control can reclaim 8.6 MaF of storage to benefit salmon resources while restoring the Columbia and Snake rivers back to a natural peaking hydrograph. River and estuary habitat would improve. Natural River plan shifts winter flow into spring, refills by May 31st, and passes inflow in June. Flood risk increases from 10% to 18% but will decrease as global climate warming continues.Natural River plan shifts winter flow into spring, refills by May 31st, and passes inflow in June. Flood risk increases from 10% to 18% but will decrease as global climate warming continues. Need to run daily flood risk & life-cycle studies.Need to run daily flood risk & life-cycle studies.