Altered Flood Control, Climate Change, and Rebuilding Pacific Northwest Salmon Stocks

Transcription

1 Altered Flood Control, Climate Change, and Rebuilding Pacific Northwest Salmon Stocks Kyle Dittmer Hydrologist Meteorologist March 24, 2006 Columbia River Inter-Tribal Fish Commission Portland, Oregon

2 Introduction A Natural River reservoir operation promotes environmental conditions that are in harmony with the salmon s biological timing. (Return of the River Independent Science Group, 2000, 12.htm) Altered flood control and earlier reservoir refill can create a more natural flow regime. Modified operations are at Grand Coulee (WA), Dworshak (ID), Brownlee (ID), Libby & Hungry Horse (MT), Mica & Arrow (British Columbia).

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4 Natural Flow regime Concept Natural Flow improves salmon survival with: increased turbidity & habitat, decreased travel time, higher river and estuary productivity. Altered Flood Control uses less reservoir drafts during winter and early spring. More water is shifted from winter to spring. Summer flow augmentation: MaF. Nez Perce Tribe Summer Plan for Dworshak. Modified VAR-Q Q used for Libby & Hungry Horse.

5 GENESYS Hydro-generation model This NPPC model uses monthly time steps. Operations are specified at major PNW dams. Model runs sequentially from dam-to to-dam. Record spans 50 Water Years: Output: flow, spill, pool elevations, generation. Rule Curves altered for flood control operations. In 2006 (?), model upgrades: 70 water years ( ) 1999) and maybe half-month time steps.

6 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 (temporal data) OPERATIONS Files: Flow Limits, Spill, Storage Limits Operation-Exception Program Control Files-- Pre-Processing 50 years historical, observed data Proportional draft, PNCA specified GENESYS Multi-Dam Prioritized operating parameters Draft specific reservoirs, if desired Program Control Files-- Post-Processing Graphical Displays: Outflow, Pool Elevations, Storage Tabular Reports and Data Files

7 Corps System Flood Control Regulate Flood of 1894 to 800 kcfs (primary) and 600 kcfs (secondary), at The Dalles. Flood flow, 550 kcfs; and Bank-full, 450 kcfs. Reservoirs systematically drawn down from January through April 30. Reservoir draft depends on monthly final Water Supply (Volume) Forecast. Corps does not look at trend of WSF and may overdraft reservoirs. Reservoirs start refilling after May 1st. Reservoirs fill by June 30th and pass inflow.

8 Long-term Effects of Corps Flood Control

9 Altered Flood Control Global warming will reduce winter snow packs. Spring flood control drafts can be reduced. New forecast tools (eg, UW, NOAA, CRITFC) can reduce premature flood control drafts. Fill all reservoirs by May 31st, not June 30th. Inflows passed in June for a higher spring peak. Altered Flood Control adds more storage: 508 KaF at Grand Coulee, 874 KaF at Libby, 366 KaF Hungry Horse, 420 KaF at Dworshak, 205 KaF at Brownlee, 507 KaF from Mica and Arrow. Total = 2.9 MaF.

10 How Much Water is Saved? Dworshak Brownlee Each year on average, CRITFC s Altered Flood Control can shift the entire volume of Dworshak and Brownlee reservoirs to benefit salmon passage!!!

11 Grand Coulee: Flood Control Rule Curve Storage (ksfd) CRITFC Altered Flood Control (long term) Federal Flood Control

12 Grand Coulee: Flood Control HIGH YRS Storage (ksfd) CRITFC Altered Flood Control (long term) Federal Flood Control

13 Grand Coulee: Flood Control LOW YRS Storage (ksfd) CRITFC Altered Flood Control (long term) Federal Flood Control

14 Arrow pool: Flood Control Rule Curve Storage (ksfd) CRITFC Altered Flood Control Federal Flood Control

15 Dworshak pool: Flood Control Rule Curve Storage (ksfd) CRITFC Altered Flood Control Federal Flood Control

16 Dworshak pool: Flood Control HIGH YRS Storage (ksfd) CRITFC Altered Flood Control Federal Flood Control

17 Dworshak pool: Flood Control LOW years Storage (ksfd) CRITFC Altered Flood Control Federal Flood Control

18 Brownlee pool: Flood Control Rule Curve Storage (ksfd) CRITFC Altered Flood Control Federal Flood Control

19 Libby pool: Flood Control Rule Curve Storage (ksfd) CRITFC Altered Flood Control Federal Flood Control

20 Results of Natural Peak River plan using GENESYS model About 2.9 MaF more water per year is flushed. Average June peak at The Dalles is 327 kcfs. High water year peak is 417 kcfs (13 years). Low water year peak is 220 kcfs (11 years). McNary spring flows increase by 7% and summer flows increase by 5%. Residence times increase at DWR, HGH, LIB. Generation increases in summer, less in winter. Annual generation: 154,600 MW (6383 MW less than 2000 Biological Opinion) Tribal Energy Vision Paper:

21 Columbia River at The Dalles: WY Outflow (cfs) 340, , , , , , , , , , , , ,000 80,000 60,000 Priest Rapids Outflow CRITFC Natural River 2000 Biological Opinion

22 Columbia River at The Dalles: HIGH Years 500, , ,000 Outflow (cfs) 350, , , , , ,000 50,000 Priest Rapids Outflow CRITFC Natural River 2000 Biological Opinion WY 1997 Observed (record 158 MaF) Bankfull (Portland / Vancouver)

23 Columbia River at The Dalles: LOW Years 240, , ,000 Outflow (cfs) 180, , , , ,000 80,000 60,000 Priest Rapids Outflow CRITFC Natural River 2000 Biological Opinion WY 1977 Observed (record low 53 MaF)

24 Snake River at Lower Granite 120, , ,000 90,000 80,000 Outflow (cfs) 70,000 60,000 50,000 40,000 30,000 20,000 10,000 0 Hells Canyon Outflow CRITFC Natural River Dworshak Outflow 2000 Biological Opinion

25 Columbia River at Grand Coulee: WY Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

26 Columbia River at Grand Coulee: HIGH Years Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

27 Columbia River at Grand Coulee: LOW Years Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

28 Columbia River at Arrow Lakes (BC) 1444 Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

29 NF Clearwater River at Dworshak: WY Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

30 NF Clearwater River at Dworshak: HIGH Years Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

31 NF Clearwater River at Dworshak: LOW Years 1600 Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

32 Snake River at Brownlee: WY Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

33 Kootenay River at Libby Elevation (feet above mean sea level) CRITFC Natural River Federal Operations (2000 Biological Opinion)

34 Kootenay River at Libby 22,000 20,000 18,000 16,000 Outflow (cfs) 14,000 12,000 10,000 8,000 6,000 4,000 2,000 0 CRITFC Natural River 2000 Biological Opinion

35 SF Flathead River at Hungry Horse Outflow (cfs) 6,500 6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1, CRITFC Natural River 2000 Biological Opinion

36 Benefits to Northwest Salmon Enhanced ecosystem health and diversity. Resident fish populations enjoy more habitat. Speed juvenile migrants to the estuary. Transport more woody and organic debris. Less predation. Cooler passage water. Increase estuary plume-- --critical habitat. Provide adequate flow for returning adults. Re-connect and reactivate flood-plain habitats.

37 How a Natural River plan may Impact the Pacific Northwest More salmon return to spawn while Columbia Tribal treaties are honored. Flood risk to Portland: 16% vs. 14% (Federal) vs. 42% (historic). Bank-full flow: 50% risk versus 42% (Federal) vs. 64% (historic). Spring flood risk is offset by global warming. Less winter time wind erosion on the banks of Lake Roosevelt (WA). Less sediment sloughing in affected reservoirs.

38 Spring Flood-Frequency (WY ): Columbia River at The Dalles 1,000,000 16% 50% Flow (cfs) 14% 42% 100, Probability of flow being equaled or exceeded Historical Observed peak Federal Operation peak CRITFC Natural Peak Bank Full Flood Flow

39 700, , , , , , , , , , , , ,000 The Dalles Daily Modeled Flows (High yrs) Observed (1933,48,50,56,67) Minor Damage (600 kcfs) Flood Flow (550 kcfs) Bankfull (450 kcfs) CRITFC Natural-Peak Federal Operations Observed WY 1997 (Record High) Flows (cfs) Apr-1st Apr-7th Apr-13th Apr-19th Apr-25th May-1st May-7th May-13th May-19th May-25th May-31st June-6th June-12th June-18th June-24th June-30th July-6th July-12th July-18th July-24th July-30th Aug-5th Aug-11th Aug-17th Aug-23rd Aug-29th Sept-4th Sept-10th Sept-16th Sept- Sept-28th

40 IMPACT OF GLOBAL WARMING BY THE YEAR 2020 Columbia River at The Dalles: 2020 (WY ) Outflow (cfs) 400, , , , , , , , , , , , , , , ,000 80,000 60,000 CRITFC Natural River -- GW 2020 (COMP run) CRITFC Natural River Biological Opinion -- GW 2020 (COMP run) Federal Operations (2000 Biological Opinion)

41 IMPACT OF GLOBAL WARMING BY THE YEAR 2040 Columbia River at The Dalles: 2040 (WY ) Outflow (cfs) 400, , , , , , , , , , , , , , , ,000 80,000 60,000 CRITFC Natural River -- GW 2040 (COMP run) CRITFC Natural River Biological Opinion -- GW 2040 (COMP run) Federal Operations (2000 Biological Opinion)

42 Flow Summary Seasonal Flow (McNary): Seasonal Flow (Lower Granite): Seasonal Flow (Priest Rapids): 2000BiOp RivOps Nat.River 2000BiOp RivOps Nat.River 2000BiOp RivOps Nat.River Target k Target k Target 135,000 Spring 269, , ,440 Spring 97, , ,755 Spring 169, , ,746 Target 200,000 Target 50-55k Summer 180, , ,898 Summer 52,217 52,103 52,779 FLOW AUGMENTATION-- Columbia (KaF) 2000BiOp RivOps Nat.River Non-Treaty Storage (Mica Dam, BC) ,000 Banks Lake (WA) FLOW AUGMENTATION-- Snake (KaF) 2000BiOp RivOps Nat.River Upper-and-Middle Snake ,427 Brownlee Dam

43 Summary Altered flood control can offer 2.9 MaF of extra flow to benefit salmon stocks while move the Columbia and Snake Rivers back to a natural flow pattern, have reasonable flood protection, and take advantage of global warming. Natural River plan shifts winter flow into spring, refills dams by May 31, and pass inflow in June. Flood risk increases from 14% to 16% but will decrease as global climate warming continues. Next step: Daily flood risk & life-cycle studies.