Grand Coulee Dam and the Columbia Basin Project usa final Report: November 2000
Table 4.4.2 Fish Passage Facilities at Major Dams of the Columbia River Basin
Download 5.01 Kb. Pdf ko'rish
|
- Bu sahifa navigatsiya:
- Table 4.4.3. Components of Salmon and Steelhead Habitat Quality
- 4.6.1 Major Changes in Operations Over Time
- Table 4.6.1. Stages of GCD Project Operations Time Period Characteristics
- Table 4.6.2. Optimal Conditions for Different Types of River Uses River Use Description
- 4.6.2 Current GCD Operations
- Table 4.6.3. Grand Coulee Dam Operating Constraints Month General Operating Constraints for Power January
- February • Operate to higher of 1 260ft (333m) reservoir elevation or 85% confident of refill to flood control rule curve by 10 April March
Table 4.4.2 Fish Passage Facilities at Major Dams of the Columbia River Basin Dam Year Dam Completed River Fish Passage Adult Juvenile Rock Island 1933 Mid-Columbia Yes Yes Bonneville 1938 Lower-Columbia Yes Yes Grand Coulee 1942 Upper-Columbia No No Chief Joseph 1955 Upper-Columbia No No McNary 1957 Lower-Columbia Yes Yes The Dalles 1957 Lower-Columbia Yes Soon Brownlee 1959 Snake No No Priest Rapids 1959 Mid-Columbia Yes Yes Rocky Reach 1961 Mid-Columbia Yes Yes Oxbow 1961 Snake No No Ice Harbor 1962 Snake Yes Soon Wanapum 1964 Mid-Columbia Yes Yes Hells Canyon 1967 Snake No No Wells 1967 Mid-Columbia Yes No John Day 1968 Lower-Columbia Yes Yes Lower Monumental 1969 Snake Yes Yes Little Goose 1970 Snake Yes Yes Lower Granite 1975 Snake Yes Yes Source: University of Washington, 1999. In addition to their effect as physical barriers, the numerous dams in the Columbia River Basin impact salmon and steelhead habitat in a number of ways. First, reservoir creation often eliminates prime spawning habitat. Second, the system-wide operation of multi-purpose water projects in the basin has been geared towards maximising hydropower generation and flood protection. This has changed the river’s natural flow regime. The end result is a set of conditions that have adverse effects on juvenile outmigration. For example, dams slow river velocities, thus impeding the ability of the river to “help the fish along” in their passage to the sea. Delays during outmigration can have major effects on smoltification, the complex biological transformation that enables the fish to survive in a marine environment. If smoltification does not take place within a particular timeframe, the fish will not be able to survive in the ocean. Third, because of thermal storage in reservoirs, salmon and steelhead in the Columbia River system, which are cold-water fish, are exposed to higher than normal temperatures. 139 4.4.1.4 Habitat Habitat quantity and quality are both important in salmon and steelhead production. Dams in the basin have contributed significantly to habitat degradation, but they are not the only cause. Other practices, such as timber harvesting, wetland destruction, agricultural practices, and irrigation continue to decrease the availability of habitat. Table 4.4.3 lists important components of salmon and steelhead habitat. In addition to inland habitat, climate and ocean conditions also have a significant influence on salmon and steelhead health. In the past decade, scientists have become aware of the effect of El Nino-like climate shifts that can persist for several decades. These shifts, which increase seawater temperatures and interfere with upwelling, wind, and current transport, can have major effects on the marine food- web, thereby influencing salmon survival at sea. Because of these ocean effects, the number of fish are produced in the rivers may be less influential than is widely believed, as these climate effects may preclude, and even confound, a lot of what are perceived to be fish recovery problems in rivers (Bennett 1999). Grand Coulee Dam and Columbia Basin Project 93 This is a working paper prepared for the World Commission on Dams as part of its information gathering activities. The views, conclusions, and recommendations contained in the working paper are not to be taken to represent the views of the Commission Table 4.4.3. Components of Salmon and Steelhead Habitat Quality • Water quality • Pool quality • Large woody debris supply • Water quantity • Habitat diversity • Water temperature, availability of shade • Flow regime • Sediment loading • Water velocity • Gravel quality • Instream cover • Bank stability • Gravel quantity • Overhead cover • Presence of under cut banks • Pool quantity • Riparian vegetation • Fish passage 4.4.2 Larger Ecosystem Effects The role of salmon and steelhead in transferring nutrients from the Pacific Ocean to the Columbia River Basin is a relatively new subject of study. In the context of GCD, the nature of this nutrient transfer is summarised here. Before construction of GCD (and the two main-stem dams that preceded it, Rock Island Dam and Bonneville Dam), salmon migration to the upper basin involved a nutrient transfer because salmon were an important food source for other animals. Spawning and spawned-out salmon comprised an important source of nutrition for animals such as bears 140 and eagles, effectively transferring nutrients from the ocean to the relatively sterile rivers and streams where the fish ultimately spawned. Bears ate the salmon, and they also recycled salmon-derived nutrients important to plant growth (eg, nitrogen and phosphorus) through their faeces (Olsen, 1998). Additionally, decaying salmon formed a nutrient base for organisms lower on the food chain that fed on decomposed fish bodies. The presence of an extensive dam system, including GCD and the other major projects in the basin, has severely compromised the traditional flow of nutrients to ecosystems in the upper basin region. Scientists are only beginning to unravel the implications of this alteration in nutrient flow. 4.5 Cumulative Socioeconomic Impacts In the context of the Columbia River Basin, the significance of cumulative socioeconomic impacts of water resource development projects is undeniable. Indeed, the notion of cumulative effects is implicit in the Corps’ “308 Report,” which turned out to be the initial version of a master plan for water resource development projects on the main-stem within the US portion of the basin. The 308 report, which was named after House Document No. 308 of 1926 (US Congress, 1926) mandating detailed studies of the Columbia River Basin (among others), included two principal parts: a report by Major Butler for the portion of the Columbia River above the Snake, and one by Major Kuentz for the portion of the Columbia below the Snake (USACE, 1933). These reports paid a great deal of attention to the overall development of industry and agriculture within the US portion the basin. The significance of the reports by Butler and Kuentz is undeniable, particularly in light of the projects actually built. 141 Indeed, the Corps modified and updated the original 308 report during the 1940s to maintain its viability as a long-range planning document. Manifestations of the cumulative socioeconomic impacts of water resources development in the Columbia River Basin are not difficult to find. Indeed, the timing of both irrigation developments and hydroelectric projects were intentionally sequenced to match the increasing demands for agricultural outputs and electricity. Collectively, these additions of hydroelectric power and irrigated acreage had an extraordinary impact on the overall development of the US Northwest. Grand Coulee Dam and Columbia Basin Project 94 This is a working paper prepared for the World Commission on Dams as part of its information gathering activities. The views, conclusions, and recommendations contained in the working paper are not to be taken to represent the views of the Commission Another set of cumulative effects involves the influence of the CBP's agricultural outputs on farming activities in other parts of the US. While we were unable to identify studies of how subsidies for irrigation water to CBP growers allowed them to out-compete growers of similar crops in other parts of the country, several people we interviewed during the course of the study raised the issue. In particular, it appears to be common knowledge in Idaho that many potato farmers in that state — once one of the leading producers of potatoes in the US — shifted to other crops in the face of very stiff price competition from potato growers receiving CBP irrigation water. In addition to effects on US farmers outside the CBP area, the availability of subsidised irrigation water on the Columbia plateau has also affected farmers in BC. An analysis by W.R. Holm and Associates (1994: 84-90) examines the shift to growing higher valued crops on CBP lands in the period from 1962 to 1992. In the investigation, the following five crops were considered: apples, potatoes, asparagus, onions, and grapes. According to Holm’s analysis, the shift to higher valued crops in this period meant increased competition for farmers in British Columbia who produced the same crops without the advantage of subsidised irrigation water. Relationships between cumulative socioeconomic impacts and cumulative ecosystem impacts are also notable. Consider, for example, the links between incremental dam construction, effects on salmon migration, and consequent social and cultural impacts on upstream Indian tribes. As noted in Section 3.5, Rock Island and Bonneville dams were both completed before GCD, and the negative effects of Rock Island and Bonneville dam on salmon and steelhead migrations were notable. Debates on the impact of GCD on fisheries were influenced by the cumulative effects of these two earlier dams. In particular, during the mid-1930s, James O'Sullivan, executive secretary of the Columbia River Development League, countered critics of GCD concerned about salmon migration by referring to effects of the two earlier dams. O'Sullivan argued that as a result of the combined effects of Bonneville and Rock Island dams, only one half of one percent of the Columbia's salmon run would probably remain by the time those salmon that survived reached the Grand Coulee. He also argued that the commercial value of the salmon fishery was a small fraction of the value of outputs from dam construction on the Columbia River. As noted in previous sections, the decision to eliminate the upstream migration of salmon by constructing GCD had major cultural and social impacts on Native Americans in the US and First Nations in Canada. 4.6 System Operations System-wide objectives, laws, and policies affecting all major projects in the Columbia River Basin largely govern GCD operations. Historically, the two dominant functions of the reservoir system, including GCD, have been hydropower and irrigation. After 1972, flood control was added as a major purpose of the project. Beginning with the 1980 Northwest Power Act, the major operational changes for GCD and other projects in the Columbia River system focused on the need to more adequately address requirements for maintaining and enhancing anadromous fish populations. In 1995, the NMFS biological opinion concerning the 1991/92 ESA listing of three species of endangered Snake River salmon heralded another change in project operations. According to interviews that we conducted with Reclamation and BPA staff (Jaren 1999; Rodewald 1999; McKay 1999), the NMFS biological opinion is the dominant factor now driving system operations. 4.6.1 Major Changes in Operations Over Time Four major stages, characterised in Table 4.6.1, mark the evolution of GCD operations in its basin-wide context. At the time GCD was completed, the major focus of operation of federal dams in the Columbia River Basin was on power generation at the project level. Over time, more and more projects and project purposes were added, and operations moved from the individual project level to the system level. Grand Coulee Dam and Columbia Basin Project 95 This is a working paper prepared for the World Commission on Dams as part of its information gathering activities. The views, conclusions, and recommendations contained in the working paper are not to be taken to represent the views of the Commission Between 1942 (the time of GCD completion) and 1948, GCD was operated primarily for hydropower- generating purposes; no significant flood control was provided during that period. Between 1948 and 1972, GCD was relied on more heavily for flood control, and power management in Columbia River system began shifting from a project specific to a system-wide focus; CBP also came on line. During this time, GCD was one of the major sources of power generation on the US side of the Columbia River Basin. The ability of GCD to play a role in significantly protecting against floods was limited until the Columbia River Treaty dams became operational in the early 1970s (Brooks 1999). Additionally, the completion of the Treaty dams in the US and Canada made significant hydropower optimisation possible. After 1973, power generation and flood control activities were managed at a basin-wide level. The environmental aspects for individual projects were managed under requirements for federal agencies to conduct environmental impact assessments under the National Environmental Policy Act (NEPA) of 1969. The Northwest Power Act of 1980, the creation of the NPPC, and its 1983 fish and wildlife programme, marked the addition of anadromous fish concerns as a major basin-wide management issue (Rodewald 1999). Table 4.6.1. Stages of GCD Project Operations Time Period Characteristics 1940s to 1950s - Power generation at the project level 1950s to early 1970s - Power generation at the project level - Flood control at the project level - Irrigation Early 1970s to early 1980s - Power generation at the system level - Flood control at the system level - Irrigation - Environmental impact mitigation at the project level Early 1980s to present - Power generation at the system level - Flood control at the system level - Irrigation - Environmental impact mitigation at the system level (particularly for anadromous fish) In 1990, BPA, the Corps, and Reclamation used the environmental impact statement process under NEPA to conduct a joint review of 14 major projects in the basin (including the GCD) to develop an overall system operating strategy that would balance the varied, and sometimes conflicting, needs of all water users in the basin (see Table 4.6.2). For example, flood control requires reservoirs to be drawn down in early spring, whereas resident fish require stable reservoir levels year round. The final report, the Columbia River System Operation Review Final Environmental Impact Statement, was issued in 1995 and outlines the general system operating strategy for GCD that is used today (Jaren 1999; Rodewald 1999; MacKay 1999). Table 4.6.2. Optimal Conditions for Different Types of River Uses River Use Description Anadromous Fish Streamflows as close to “natural” river conditions as possible, with main-stem reservoirs well below spillway levels. Cultural Resources Stable reservoir elevations year round Flood Control Reservoirs drafted in early spring to capture snowmelt inflows Irrigation Full reservoirs during the growing season (March to September) Power Reduce or eliminate non-power operating constraints on the system Resident Fish Stable reservoirs year round, with natural river flows Recreation Full reservoirs during the summer (May–Oct) and stable downstream flows Water Quality Natural river flows with minimum spill Grand Coulee Dam and Columbia Basin Project 96 This is a working paper prepared for the World Commission on Dams as part of its information gathering activities. The views, conclusions, and recommendations contained in the working paper are not to be taken to represent the views of the Commission Source: USDOE et al., 1995 (Main Report): 4-2. Because GCD is a large storage project relative to other projects in the basin, it plays a key role in system-wide operations concerning both power generation and flood control. The natural flow of the Columbia River is not well correlated with the temporal pattern of power demand. In the US Northwest, power demand is highest in the winter and lowest in the summer, whereas the natural flow pattern of the river would have high flows in the spring and summer and low flows in the winter. Thus, the purpose of large storage projects like GCD is to adjust the river’s natural flow pattern to mirror power demand more closely (DOE et al, 1992). This entails storing spring and summer snowmelt in reservoirs for eventual release in the fall and winter. For the most part, this pattern of reservoir operation is also compatible with flood control requirements, which require capturing spring and early summer runoff. However, at times, this operating strategy can be in direct conflict with operating requirements for other project purposes, such as recreation and flow augmentation for the maintenance of anadromous fish. Details of how GCD operates in relation to specific project purposes (eg, flood control, hydropower generation, and anadromous fish) are discussed in other sections of this report and in the Annex titled “System Operations — Hydropower, Flood Control, and Anadromous Fish Management Activities”. The discussion below concerns the general approach to operating GCD in light of all the project’s various purposes. 4.6.2 Current GCD Operations Current GCD operations reflect trade-offs among various project purposes. For example, recreational users want reservoir elevation to be high in the summer, but this may conflict with flood control needs, which can call for elevations to be low in the summer to accommodate incoming runoff. For GCD, Reclamation develops operating requirements specific to irrigation at CBP, and BPA requests reservoir levels for power within those limits, given flood control constraints and anadromous fish needs. The three main functions that are managed on a system-wide basis in the Columbia River Basin are hydropower operations, flood control, and anadromous fish enhancement measures. The specific details of operations that pertain specifically to these functions are discussed in the Annex titled “System Operations — Hydropower, Flood Control, and Anadromous Fish Management Activities”. Besides power generation, flood control, irrigation, and anadromous fish, other major operational components of the project include resident fish and recreation. For irrigation, reservoir levels must be at a minimum level (1 240ft, or 327m) so that irrigation works function properly. While only about 3% of the river’s flow is withdrawn for irrigation at GCD, the combined effect of these withdrawals, along with other water uses, is important. Storing water in reservoirs to meet irrigation demands alters river flow for other uses (eg, flow augmentation) Irrigation activities for projects in FCRPS are managed on a project- by-project basis, however, certain irrigation system requirements are taken into consideration when planning for system-wide operations. Table 4.6.3 illustrates the various constraints that determine how GCD is operated. For example, from January to April, flood control criteria dominate. Irrigation pumping runs from March to September, and the reservoir must be at or above a certain level to satisfy irrigation requirements. From May to September, the “Technical Management Team” (TMT), an interdisciplinary group representing the operating agencies (ie, the Corps, Reclamation, and BPA), NMFS, the tribes, and other groups working on anadromous fish conservation, convenes by teleconference weekly to determine how GCD operations might be conducted so as to enhance conditions for anadromous fish. Over the summer months, recreational interests desire the reservoir level to be around 1 285ft (339m). And in September and October, reservoir levels are supposed to be between 1 283ft (339m) and 1 285ft (339m) to enhance kokanee spawning. Grand Coulee Dam and Columbia Basin Project 97 This is a working paper prepared for the World Commission on Dams as part of its information gathering activities. The views, conclusions, and recommendations contained in the working paper are not to be taken to represent the views of the Commission Table 4.6.3. Grand Coulee Dam Operating Constraints Month General Operating Constraints for Power January • Operate to higher of 1 260ft (333m) reservoir elevation or 85% confident of refill to flood control rule curve by 10 April February • Operate to higher of 1 260ft (333m) reservoir elevation or 85% confident of refill to flood control rule curve by 10 April March • Draft to higher of 1 240ft (327m) or 85% confident of refill to flood control rule curve by 10 April • Begin irrigation pumping April • Operate to flood control rule curve • Continue irrigation pumping • Inchelium Ferry out of service if reservoir elevation level less than 1 225ft (323m) May • Target 1 240ft (327m) reservoir elevation level for irrigation pumping • Begin work of TMT • Spill Memorial day through 30 September for laser light show June • Refill to 1 285ft (339m) for recreation (can be overruled by TMT) • Continue TMT • Continue irrigation pumping • Continue spill for laser light show Download 5.01 Kb. Do'stlaringiz bilan baham: |
Ma'lumotlar bazasi mualliflik huquqi bilan himoyalangan ©fayllar.org 2024
ma'muriyatiga murojaat qiling
ma'muriyatiga murojaat qiling