1994 Columbia River Basin Fish and Wildlife Program
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1994 Columbia River Basin Fish and Wildlife Program |
| Council document 94-55 | |
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Contents
5.0 Mainstem Passage Experimental Program
5.1 Coordinate River Operations
5.2 Improve Snake River Flow and Velocity
5.3 Snake River Drawdown Strategy
5.4 Improve Columbia River Flow and Velocity
5.5 Conduct Additional Research and Monitoring
5.6 Complete Installation of Bypass System
5.7 Reduce Predation and Competition
5.8 Transportation
5.9 Pursue Monitoring and Dispute Resolution
Salmon and steelhead begin and end life in many diverse streams and tributaries
throughout the Columbia River Basin, but they all eventually share one route.
They must make their way down and ultimately back up the mainstems of the
Columbia and Snake rivers as they go to and from their spawning beds. Between
passages, they spend most of their adult lives in the Pacific Ocean.
Given that their unusual life cycle depends on a long river journey that can stretch hundreds of miles, it is clear that safe passage is paramount to their survival. Downstream passage is especially dangerous for juveniles because of the effects of dams and slow-moving reservoirs, such as turbine, bypass and spill-related mortalities, predation, migration delays and high water temperatures. The fish are on a biological time clock. To reach the ocean safely, the spring migrants must complete their downstream journey quickly.
Development of the dams has greatly altered the natural flows and cross-sectional areas of rivers in the basin. The spring runoff is stored in reservoirs so it can be used to produce electricity, as well as to provide for irrigation, transportation, recreation and flood control throughout the year. However, this practice and others also reduce river flows, particularly during the spring when juvenile salmon and steelhead are migrating downstream to the ocean.
The combination of reduced flows and the greater cross-sectional area of the river due to reservoir storage slows the juvenile fish as they migrate to the ocean. An increase in travel time in the river affects the migratory behavior of juvenile fish and increases their exposure to predatory fish and birds. Reduced flows also endanger juvenile salmon by raising water temperatures, altering water chemistry and increasing susceptibility to disease.
The physical problems faced by salmon and steelhead have been compounded by the diversity of the parties involved in the river basin's management. Even with major efforts to increase the amount of water for salmon and steelhead, matching water supplies with the needs of spring and summer migrating fish poses a substantial problem of analysis and coordination.
From the start in 1982, the Council's program recognized and focused on the importance of improving mainstem survival for both smolts and returning adult salmon. However, in recent years, the problem has been exacerbated by a series of low water years, caused primarily by drought conditions in the southern and eastern parts of the basin. The Snake River Basin has been particularly dry. It is believed that this drought contributed significantly to a reversal in the increases in run sizes observed in the early 1980s.
To increase salmon survival in the mainstem, the approach must be multifaceted. Flows and reduced water temperatures alone are not sufficient. Control of predation, improved and/or new fish transportation methods and completion of programs to install and upgrade screens at both the dams and all unscreened water diversions are all vital to successful mainstem passage.
When it first addressed these problems in 1982, the Council developed a ?water budget? to be used between April 15 and June 15. The water budget is a block of water set aside for fish and released during the spring runs to create an artificial freshet that speeds juvenile fish to the ocean. Separate water budgets were established for measurement at Priest Rapids Dam on the Columbia River and Lower Granite Dam on the Snake River, both in Washington.
Through the use of the water budget, the fish and wildlife agencies and tribes could increase spring flows to aid the downstream migration of juveniles. The Council established a schedule of firm power flows for the April 15 to June 15 period to provide a base from which to measure water budget use. (Firm power is the electricity that the hydropower system guarantees it can produce. That guarantee was premised on the assumption that this amount of hydropower is available even in historic low, or ?critical,? water conditions.) The water budget may be used to implement any flow schedule that would ensure juvenile salmon survival, provided the flows allow existing firm non-power commitments, such as flood control, to be met.
The Columbia River Inter-Tribal Fish Commission contributed an important element to the development of the water budget by pointing out that optimum flows for downstream migration are only needed when the fish are present. Recognition of this factor led to the concept of 'shaping? fish flows, which in turn led to the concept of a specified volume of water rather than specified flow levels. This volume of water, to be shaped by the fish and wildlife agencies and tribes, became the water budget.
To improve coordination between fish and power interests, the Council called for two coordinators known as ?fish passage managers? (originally called water budget managers). One was appointed by the basin's fish and wildlife agencies and one selected by a majority of Columbia River Basin tribes. The agencies and tribes are now operating with a single fish passage manager. The Council provides a fish passage advisor on its staff to review the operation of the water budget, advise the Council on all matters related to the water budget and assist the Council in resolving water budget disputes.
The Council called for a study of the water budget's biological effects, including reductions in smolt travel time, improvements in smolt survival and impacts on the power system. In 1987, the fish and wildlife program was modified to encourage experimentation with and evaluation of alternatives for implementing the water budget.
In 1991 and 1992, with new data showing continuing declines in wild stocks, the Council adopted two kinds of measures to supplement the earlier water budget volumes. The first was a set of immediate measures that could be implemented in time for the 1992 fish migration. Second, recognizing that these immediate measures are inadequate to rebuild some weak populations, the Council identified a set of intermediate-term measures.
In this rulemaking, the Council has concluded that additional actions to improve mainstem survival of migrating salmon must be taken. Analyses conducted by the Council indicate that, absent additional action and a substantial change in ocean conditions, salmon populations in the Snake Basin will not rebuild and will, in all likelihood, go extinct. This conclusion is consistent with that reached by the Council in developing its 1992 salmon strategy. In that rulemaking, the Council put in place a number of immediate survival improvements, while acknowledging that the measures would be insufficient to protect all weak populations or rebuild salmon populations to levels specified in the Council's goals.
The urgency of action has only been heightened by the exceedingly poor returns of the past two years and the even worse projections for the coming several years. These constitute historical low numbers in the population and raise the specter of extinction. While it appears clear that a portion -- perhaps a substantial portion -- of the most recent declines can be attributed to poor ocean survival conditions and the effects of a persistent drought in the region, the Council is persuaded that a sound salmon rebuilding program must be able to withstand periodically adverse natural circumstances. The salmon runs were able to survive poor natural conditions in the past and would be able to survive in today's conditions but for a wide variety of human-caused sources of mortality. These mortalities must be reduced. Doing so will require additional action directed toward restoring the ecological health of the Columbia River ecosystem.
These additional actions are detailed below and are tied to an explicit adaptive management approach that will ensure careful monitoring and evaluation of impacts so mid-course corrections can be made. The Council believes, on the basis of the best available scientific information, that these actions are likely to improve the survival of anadromous fish and that immediate survival improvements are needed or important components of the salmon runs will likely be lost to extinction. Flow and velocity improvements are called for on the basis of agency, tribal and other scientific information on the reasonableness of the relationship between flow, migration speed and salmon survival. While the relationship is not precisely known, and is attended by much debate, the Council concurs with the Oak Ridge National Laboratory review and believes that a positive characterization of this relationship is reasonable, and merits pursuit through a variety of actions contained in this program.
At the same time, the Council explicitly acknowledges the biological uncertainties associated with the complex ecosystem needs of the salmon and is vitally interested in seeing the level of understanding and the quality of scientific information improved expeditiously. Accordingly, the Council has established a means whereby the region can proceed with actions that appear reasonably likely to improve survival in a significant way while providing the opportunity to learn more about the biological needs of the salmon.
Further, the Council has included a number of measures to protect resident fish populations from excessive power operations or anadromous fish operations of the hydroelectric system that could undermine resident fish.
In the 1991-93 amendment process and the 1994 amendment process, the fish and wildlife agencies and tribes recommended several objectives related to hydroelectric project operations. Specifically:
Commentors expressed a variety of concerns about these objectives. For example, the Upper Columbia United Tribes and the Colville Tribe opposed flow augmentation on the order of 140,000/300,000 cubic feet per second, because of the effects it could have on resident fish in Grand Coulee. At the same time, Montana's integrated rule curves show that operating the hydropower system to protect resident fish and other reservoir values may mean more water for flow augmentation downstream. Idaho Department of Fish and Game also urged caution in augmenting flows for salmon, potentially at the expense of riverine resident fish and wildlife. To take another example, if stored water must be released to control summer temperatures when they are above 62 degrees, spring flow augmentation may have to be reduced to ensure that sufficient cold water is available later for temperature control. There are other examples -- river analysis shows that in some water years summer flow objectives may conflict with spring flow objectives -- but the point is obvious. It is not clear when and how these objectives can be achieved, particularly in low water years, and particularly when the basin experiences a succession of low water years, as the last six or seven have been.
The recommendations described above are for operational objectives. Each operational objective must have a biological objective. Some commentors were skeptical that these operational objectives would produce the survival benefits suggested by the objectives? proponents. Giving due weight to the authorities, expertise and rights of the fish and wildlife agencies and Indian tribes, and considering the independent review conducted by the Council's consultant, Dr. G.F. Cada,1[1] the Council accepts the agencies? and tribes? judgment on the expected biological value of these operational objectives. This is not to say that the Council accepts these judgments conclusively. The scientific data are not clear, and there are genuine disagreements among capable scientists on these matters.
One of the issues raised in connection with these objectives is whether the region will be assured of an ?adequate, efficient, economical and reliable power? supply if the hydropower system is managed to meet fish and wildlife objectives. The Council has made findings on this issue in Section 1 of the program. However, these questions require further exploration for the longer term.
With this in mind, four general observations are important here:
First, for the near term, it is not clear when and how mainstem fish and wildlife objectives can be achieved along with the other authorized purposes of the hydropower system. The measures below make it considerably more likely that the region can achieve these objectives, or their velocity equivalents, recognizing that they may not be achievable in some years, especially in the near term. Inevitably, determining to what extent these objectives can be met in any given year will require careful annual planning and in-season management.
Second, beyond the near term, the Council and the region must continue to make changes in the hydroelectric system to make fish and wildlife objectives more achievable and to minimize the need for or impacts of tradeoffs among objectives, while carrying out the purposes of the Northwest Power Act.
Third, the region must evaluate the biological assumptions that underlie these operational objectives to see if changed river operations are achieving the expected biological benefits. The questions detailed in the Council's mainstem hypotheses, for example, must be investigated expeditiously through an adaptive management strategy. As new information emerges, the region must be prepared to adjust these operational objectives.
Fourth, the Council will work with Bonneville, the fishery managers, utilities and others to assure the continuing adequacy, efficiency, affordability and reliability of the region's power supply. In 1995-96, the Council will conduct a revision of the power plan that will address these issues more thoroughly.
The measures outlined below are the Council's prescription for carrying out these courses of action. Each measure or group of measures, including operational objectives, is accompanied by a statement of the measure's biological objective, which was explicit or clearly implicit in the original recommendations and in the Council's proposed amendments.
This section provides for immediate mainstem survival actions in the following areas:
This section also provides for expeditious evaluation of the following additional mainstem survival actions and schedules future Council decisions on them:
It also puts in place and reinforces a comprehensive monitoring and evaluation effort designed to help the region make wiser choices in the future. This monitoring and evaluation program builds on the prior Council rulemaking which developed a set of hypotheses for additional action and evaluation of mainstem survival. It will require a much stronger regional commitment than has been evidenced to date to conduct careful evaluations of the contentious flow/velocity/survival relationship -- a relationship on which the Council has consistently called for more rigorous analysis. The failure of the region to develop better information in this area has been due in part to the unavailability of new techniques and technologies, such as the PIT tags and necessary detectors at hydroelectric facilities. However, it has also been the result of unnecessarily prolonged debates about the need for the research, the best methods for conducting it and the desirability of taking additional action pending the development of additional information. The Council hopes that its call for immediate action and immediate improvement in the knowledge base will help resolve this long-standing impasse.
Finally, in the resident fish section of the program, the Council adopts the following measures to protect resident fish populations:
[1] Cada, G.F., et al., 1994. Review of information pertaining to the effect of water velocity on the survival of juvenile salmon and steelhead in the Columbia River basin. Oak Ridge National Laboratory, Oak Ridge, Tennessee.
[2] The amount of time microscopic food organisms, and nutrients on which they depend, spend in a reservoir. It is these organisms on which fish and the entire food chain depend. Nutrient retention time is measured by the amount of time it takes water to flow through a reservoir.
