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
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, http://www.nwcouncil.org/library/return/2000-12.htm 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).
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: 3.377 MaF. Nez Perce Tribe Summer Plan for Dworshak. Modified VAR-Q Q used for Libby & Hungry Horse.
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: 1929-1978. Output: flow, spill, pool elevations, generation. Rule Curves altered for flood control operations. In 2006 (?), model upgrades: 70 water years (1929-1999) 1999) and maybe half-month time steps.
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
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.
Long-term Effects of Corps Flood Control
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.
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!!!
Grand Coulee: Flood Control Rule Curve 2700 2500 2300 Storage (ksfd) 2100 1900 1700 1500 1300 1100 900 CRITFC Altered Flood Control (long term) Federal Flood Control
Grand Coulee: Flood Control HIGH YRS 2700 2500 2300 2100 Storage (ksfd) 1900 1700 1500 1300 1100 900 700 500 300 CRITFC Altered Flood Control (long term) Federal Flood Control
Grand Coulee: Flood Control LOW YRS 2650 2600 2550 Storage (ksfd) 2500 2450 2400 2350 2300 2250 2200 CRITFC Altered Flood Control (long term) Federal Flood Control
Arrow pool: Flood Control Rule Curve 3600 3400 3200 3000 Storage (ksfd) 2800 2600 2400 2200 2000 1800 1600 1400 1200 CRITFC Altered Flood Control Federal Flood Control
Dworshak pool: Flood Control Rule Curve 1050 1000 950 900 Storage (ksfd) 850 800 750 700 650 600 550 500 450 400 CRITFC Altered Flood Control Federal Flood Control
Dworshak pool: Flood Control HIGH YRS Storage (ksfd) 1050 1000 950 900 850 800 750 700 650 600 550 500 450 400 350 300 250 200 150 100 50 0 CRITFC Altered Flood Control Federal Flood Control
Dworshak pool: Flood Control LOW years 1050 1000 950 Storage (ksfd) 900 850 800 750 700 650 600 CRITFC Altered Flood Control Federal Flood Control
Brownlee pool: Flood Control Rule Curve 500 475 450 Storage (ksfd) 425 400 375 350 325 300 275 CRITFC Altered Flood Control Federal Flood Control
Libby pool: Flood Control Rule Curve Storage (ksfd) 2600 2500 2400 2300 2200 2100 2000 1900 1800 1700 1600 1500 1400 1300 1200 CRITFC Altered Flood Control Federal Flood Control
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: http://www.critfc.org/legal/energy_fin.html
Columbia River at The Dalles: WY 1929-1978 Outflow (cfs) 340,000 320,000 300,000 280,000 260,000 240,000 220,000 200,000 180,000 160,000 140,000 120,000 100,000 80,000 60,000 Priest Rapids Outflow CRITFC Natural River 2000 Biological Opinion
Columbia River at The Dalles: HIGH Years 500,000 450,000 400,000 Outflow (cfs) 350,000 300,000 250,000 200,000 150,000 100,000 50,000 Priest Rapids Outflow CRITFC Natural River 2000 Biological Opinion WY 1997 Observed (record 158 MaF) Bankfull (Portland / Vancouver)
Columbia River at The Dalles: LOW Years 240,000 220,000 200,000 Outflow (cfs) 180,000 160,000 140,000 120,000 100,000 80,000 60,000 Priest Rapids Outflow CRITFC Natural River 2000 Biological Opinion WY 1977 Observed (record low 53 MaF)
Snake River at Lower Granite 120,000 110,000 100,000 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
Columbia River at Grand Coulee: WY 1929-1978 1290 Elevation (feet above mean sea level) 1285 1280 1275 1270 1265 1260 1255 1250 1245 1240 CRITFC Natural River Federal Operations (2000 Biological Opinion)
Columbia River at Grand Coulee: HIGH Years Elevation (feet above mean sea level) 1290 1285 1280 1275 1270 1265 1260 1255 1250 1245 1240 1235 1230 1225 1220 CRITFC Natural River Federal Operations (2000 Biological Opinion)
Columbia River at Grand Coulee: LOW Years Elevation (feet above mean sea level) 1290 1288 1286 1284 1282 1280 1278 1276 1274 1272 1270 1268 1266 1264 1262 1260 CRITFC Natural River Federal Operations (2000 Biological Opinion)
Columbia River at Arrow Lakes (BC) 1444 Elevation (feet above mean sea level) 1440 1436 1432 1428 1424 1420 1416 1412 1408 1404 1400 CRITFC Natural River Federal Operations (2000 Biological Opinion)
NF Clearwater River at Dworshak: WY 1928-1978 1600 Elevation (feet above mean sea level) 1590 1580 1570 1560 1550 1540 1530 1520 1510 CRITFC Natural River Federal Operations (2000 Biological Opinion)
NF Clearwater River at Dworshak: HIGH Years Elevation (feet above mean sea level) 1600 1590 1580 1570 1560 1550 1540 1530 1520 1510 1500 1490 1480 1470 1460 1450 CRITFC Natural River Federal Operations (2000 Biological Opinion)
NF Clearwater River at Dworshak: LOW Years 1600 Elevation (feet above mean sea level) 1590 1580 1570 1560 1550 1540 1530 1520 1510 CRITFC Natural River Federal Operations (2000 Biological Opinion)
Snake River at Brownlee: WY 1929-1978 Elevation (feet above mean sea level) 2077 2075 2073 2071 2069 2067 2065 2063 2061 2059 2057 2055 2053 2051 2049 2047 2045 2043 2041 2039 2037 2035 CRITFC Natural River Federal Operations (2000 Biological Opinion)
Kootenay River at Libby Elevation (feet above mean sea level) 2460 2455 2450 2445 2440 2435 2430 2425 2420 2415 2410 2405 2400 2395 2390 2385 2380 2375 2370 CRITFC Natural River Federal Operations (2000 Biological Opinion)
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
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 1,000 500 0 CRITFC Natural River 2000 Biological Opinion
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.
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.
Spring Flood-Frequency (WY 1929-78): Columbia River at The Dalles 1,000,000 16% 50% Flow (cfs) 14% 42% 100,000 2 6 10 14 18 22 26 30 34 38 42 46 50 54 58 62 66 70 74 78 82 86 90 94 98 Probability of flow being equaled or exceeded Historical Observed peak Federal Operation peak CRITFC Natural Peak Bank Full Flood Flow
700,000 650,000 600,000 550,000 500,000 450,000 400,000 350,000 300,000 250,000 200,000 150,000 100,000 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
IMPACT OF GLOBAL WARMING BY THE YEAR 2020 Columbia River at The Dalles: 2020 (WY 1951-1978) Outflow (cfs) 400,000 380,000 360,000 340,000 320,000 300,000 280,000 260,000 240,000 220,000 200,000 180,000 160,000 140,000 120,000 100,000 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)
IMPACT OF GLOBAL WARMING BY THE YEAR 2040 Columbia River at The Dalles: 2040 (WY 1951-1978) Outflow (cfs) 400,000 380,000 360,000 340,000 320,000 300,000 280,000 260,000 240,000 220,000 200,000 180,000 160,000 140,000 120,000 100,000 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)
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 220-260k Target 85-100k Target 135,000 Spring 269,837 285,533 288,440 Spring 97,370 100,369 101,755 Spring 169,298 182,067 183,746 Target 200,000 Target 50-55k Summer 180,970 184,381 189,898 Summer 52,217 52,103 52,779 FLOW AUGMENTATION-- Columbia (KaF) 2000BiOp RivOps Nat.River Non-Treaty Storage (Mica Dam, BC) 0 500 1,000 Banks Lake (WA) 0 250 500 FLOW AUGMENTATION-- Snake (KaF) 2000BiOp RivOps Nat.River Upper-and-Middle Snake 427 427 1,427 Brownlee Dam 0 450 450
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.