BONNEVILLE POWER ADMINISTRATION September 2010 Columbia River high-water operations [June 1–14, 2010] The Federal Columbia River Power System is Due to the wide seasonal and annual variations in operated for multiple public purposes, including Columbia River streamflows and the high variability flood control, irrigation, power production, of wind power output, BPA has been aware for some navigation, recreation and municipal water supply. time that a combination of high streamflows and high The system is also operated to protect the river’s wind could pose new challenges for Columbia River fish, including salmon, steelhead, sturgeon and bull system operations. This expectation was fulfilled trout listed as threatened or endangered under the when high streamflows emerged for a short period Endangered Species Act. The U.S. Army Corps of this June in an otherwise low-water year. The June Engineers and Bureau of Reclamation, which own high-water event was likely a preview of situations the federal dams, operate them within constraints BPA and the region will face again and for longer established to assure the requirements of all the periods, particularly during years of heavy snowpack. multiple purposes are met. This paper describes how system operators managed The Bonneville Power Administration markets power through this first coincidence of high wind and high from the federal dams within the constraints and streamflows. In addition to actions within the hydro requirements for other river purposes. Flood control, system itself, these steps included reducing nuclear protection of fish listed under the Endangered Species plant output, storing water in Canadian reservoirs, Act, compliance with the Clean Water Act and other providing power at little or no cost to utilities to requirements take precedence over power production. displace operation of their thermal power plants, and temporarily reducing amounts of balancing reserves As part of its mission to market federal hydropower, provided to wind power projects. BPA is the primary high-voltage transmission provider in the Columbia River Basin. Consistent Many parties are involved in some aspect of these with Federal Energy Regulatory Commission operations, but few see the actions of all. This policies for open-access, non-discriminatory high- overview is intended to provide a common context voltage transmission, BPA integrates new power for regional conversations on additional approaches sources into its transmission grid that request BPA and others might take to respond to future such service.1 In the past few years, there has been high-water events as the multiple demands on the remarkable growth in wind power projects river evolve and the region’s wind generating interconnecting to BPA’s transmission grid, driven capacity grows. by renewable portfolio standards in Washington and Oregon and increasingly by California’s 33 percent The Endangered Species Act, Clean Water Act and renewable portfolio standard.2 As a result, generating Biological Opinion on FCRPS operations are binding capacity is being developed in the Northwest far in constraints on federal power production. With the advance of regional power demand. growing imbalance in Northwest power supply and demand, new protocols, policies and tools may be needed to assure reliable and equitable power 1 For details, see www.bpa.gov/corporate/pubs/fact_sheets/09fs/ operation within the physical limits of this highly factsheet_-_Investing_in_the_NW_transmission_system.pdf. interdependent system. 2 For details, go to www.bpa.gov/go/wind. BACKGROUND second (80 kcfs) to 210 kcfs in five days. Inflows into Lake Roosevelt behind Grand Coulee Dam rose Responding to the unexpected 70 percent. The January through July water supply forecast for the Columbia River Basin increased The Columbia River system typically sees periods nearly 10 million acre-feet as measured at The Dalles, of high flows in spring as the weather warms and Ore. — from about two-thirds to about three-fourths snowpack melts. After a dry winter, spring 2010 of average — between mid-May (71.2 maf) and river flows were expected to stay fairly low. mid-June (80.9 maf). Throughout April and May, FCRPS operation focused on providing enough river flow and spill These flows were more than adequate to meet flow to meet objectives designed to protect endangered and spill objectives for fish passage. Operators’ juvenile salmon migrating to the Pacific and on focus shifted to developing strategies and modifying refilling reservoirs in Idaho, Montana and Washington operations to reduce excess spill and keep total by July. dissolved gas (nitrogen saturation) at levels safe for fish. Meeting this objective involved numerous In early June, however, a strong Pacific jet stream actions quickly taken by many parties, including brought storm systems with heavy precipitation and BPA, the Corps, Reclamation, Energy Northwest, flooding in some areas. This was the first significant and utilities and independent power producers in high-water event in several years. Snake River the Northwest, British Columbia and California. flows nearly tripled from 80,000 cubic feet per Columbia RiverWater water Year Runoff year runoff (Oct-Sep) at The at The Dalles, Dalles Ore. [1929–2010] 1929 – 2010* 220 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 October – September Runoff (maf) 50 40 30 AVERAGE = 135 MAF 20 *WY 2010: Observed October–August, estimated for September 10 0 0 1 0 1929 1931 1933 1935 1937 1939 1941 1943 1945 1947 1949 1951 1953 1955 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2 * Overall, the 2009–2010 water year was another low-water year in a low-water decade. 2 Caption: The Columbia River system has limited reservoir storage. Day-average inflows HIGH FLOWS AND THE [modeled and actual June 1–13] COLUMBIA RIVER SYSTEM These graphs show how fast, hard and unexpectedly high water hit the High flows in the Columbia River system are Columbia River system. They measure successive streamflow forecasts and actual streamflows at Lower Granite Dam on the lower Snake River, not rare; there is a one-in-three chance of flows Grand Coulee Dam on the mainstem Columbia, and at McNary dam, at least as high as those of early June 2010 which lies below the confluence of the Snake and Columbia rivers. The dark blue and magenta lines depict what forecasters expected to see occurring in any year and lasting for one month as of June 1 and 2. The heavy black lines are what actually happened. or more. Other lines correspond to updated flow forecasts. The Columbia River system has an exceptionally Day-averageLOWER Lower Granite GRANITE Inflows - modeled DAM and actual June 1 - 13 wide range of high and low flows, with a historic 220 210 minimum to maximum flow ratio of 1 to 35 200 190 (compared to 1 to 5 for the Mississippi). Flood 180 170 control is a significant purpose of many of the 160 150 Northwest’s federal dams. The Vanport Flood 140 130 120 of 1948 spurred reservoir development in the 110 Flow (kcfs) 100 upper Columbia and was a major impetus for 90 80 the Columbia River Treaty with Canada in 1964, 70 60 which doubled Columbia reservoir storage. Even 50 6/1 6/2 6/3 6/4 6/5 6/6 6/7 6/8 6/9 6/10 6/11 6/12 6/13 with the Treaty reservoirs, the federal system can store less than 40 percent of an average year’s 3 Day-averageGRAN Grand CouleeD COU InflowL -EE modeled DAM and actual June 1 - 13 134 million acre-feet of runoff. 200 June 1 June 2 June 3 June 4 June 7 June 8 190 June 9 June 10 June 11 Actuals All dams in the Columbia River system are 180 highly interdependent — water released from a 170 headwaters dam can affect flows at up to 19 dams 160 150 downstream. Northwest utilities coordinate 140 power plant operations to make the best use of Flow (kcfs) 130 this interdependent hydropower under the 120 4 110 Pacific Northwest Coordination Agreement 100 established in 1964. Transmission is also an 6/1 6/2 6/3 6/4 6/5 6/6 6/7 6/8 6/9 6/10 6/11 6/12 6/13 important aspect of this interdependent system. Date Power generation opportunities can be constrained Day-Average McNary Inflow - modeled and actual June 1 – 13 June 1 JuneMcN 2 ARYJune 3 DAMJune 4 June 7 June 8 by transmission availability, and BPA Transmission June 9 June 10 June 11 Actuals 400 Services relies heavily on federal hydropower to 380 360 provide reserves that keep the electrical system 340 in balance and operating reliably. 320 300 280 Water that cannot be stored necessarily flows 260 Flow (kcfs) 240 downstream. Since the 1970s, BPA and other 220 Northwest hydro producers have routinely sold 200 180 surplus power produced during times of high 160 streamflows at very low rates to utilities in the 6/1 6/2 6/3 6/4 6/5 6/6 6/7 6/8 6/9 6/10 6/11 6/12 6/13 Northwest and California to encourage operators June 1 June 2 June 3 June 4 June 7 June 8 3 As traditionally measured at The Dalles, Ore. June 9 June 10 June 11 Actuals 4 For details, see, Columbia River System: The Inside Story. 3 ColumbColumbiaia River Runo fRiverf and S torunoffrage Co andmpare d to the is “flashy” with large surges of runoff, a higher storageColorad comparedo and Missouri toRiv ethers proportion of the runoff may be forced through Colorado and Missouri rivers the system quickly due to lack of available 140 reservoir storage.