Review of the U.S. Army Corps of Engineers’ Capital Construction Program, Part III

February 16, 1999  |  document ISAB 99-4

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Executive Summary

The Independent Scientific Advisory Board (ISAB) is responding to a request from the Northwest Power Planning Council for assistance with a congressional query. The direction from Congress identified a concern about a lack of agreed upon priorities and a set of principles and criteria for setting those priorities in the Corps Capital Construction Program. We believe the perception of a lack of prioritization stems from two sources, 1) the lack of agreement on the technical bases for action (due to uncertainties in available information), and 2) the fact that it may be necessary to provide more than one technological approach to achieve the passage goals set by the National Marine Fisheries Service (NMFS) and the Northwest Power Planning Council (Council). The U.S. Army Corps of Engineers’ (Corps’) capital construction program for fish passage at hydroelectric projects in the mainstem Columbia and Snake rivers (the Corps of Engineers' Columbia River Fisheries Mitigation Program or CRFMP) is to an extent a reflection of the region’s plans and assumptions for salmon restoration. Even so, we believe the CRFMP is insufficient for restoration efforts partly because of its lack of balance in application of measures across species and life history types. Evidence of insufficiency comes from the continuing low adult returns in most runs. We recognize that the hydroelectric system is one of many natural and anthropogenic factors that could be impacting salmon abundance, however the steady downward trend is symptomatic of a chronic problem. Unfortunately the possible role of hydroelectric passage in causing mortalities after passage, delayed mortality, is one of the major missing pieces in the Columbia Basin research program. We advise caution in making inferences about future salmon abundance based on estimates of survivals measured within the hydroelectric system until the effects of delayed mortality can be ruled out.

Regional salmon restoration plans and their implementation by the Corps can benefit from more biologically driven decisions addressing a broader diversity of life history types and species. Other grounds for decisions, such as the desire to retain familiar technologies, politically driven choices of projects and sites, and narrow concepts of the species and stocks to be protected, need to be exchanged for tests based on the criteria of biological effectiveness. Some of the projects we reviewed met these criteria very well, although others did not. Common principles from our review of projects need to be incorporated into revised plans. A process for developing and incorporating new biological and ecological insights of value for fish passage should be an integral part of the fish passage design process.

The prioritization of projects sought by the Congress, in part to lessen costs, will emerge only after a suitably diverse array of recovery options is identified and evaluated for short and long-term biological and economic effectiveness. The process of identification and evaluation in a region-wide context has just begun and we encourage it. It is important to recognize that short-term effectiveness is based on the hydroelectric system as it is now, and long-term effectiveness takes into account other major system configuration options. It is also important to note that seemingly redundant fish-protection systems, also of concern to the Congress, are sometimes necessary in the search for the most effective approaches. Given the current need for increased information on fish behavior relevant to fish passage to guide program development, we regard the present capital construction program, with some exceptions, as a set of short-term actions that can be taken to meet the immediate needs of fish passing hydroelectric projects.

Each project review raised similar issues, either as commonalties or contrasts with other reviews. Principles and guidelines of biological effectiveness were derived from a synthesis of these project reviews.

Guidelines: Our test of biological effectiveness for a proposed action considers whether the action is (1) consistent with the behavior and ecology of the species, (2) supportive of the physical and biological conditions required for successful completion of normal life history requirements for the species, (3) based upon a valid scientific rationale to indicate that the action is capable of assisting in accomplishing the specific objective, and (4) consistent with an ecosystem approach in protecting other species that could be the subject of listing in the future.

The commonalties and principles are summarized as follows.

Spill: The general principle is that all juvenile passage alternatives should be evaluated against the baseline of spill. As an avenue of hydroelectric project passage, spill more closely mimics natural situations and ecological processes than other available routes. Spill should be considered as an alternative when the improvements anticipated from other bypass technologies are not large enough to meet the passage goals.

Options Are Interrelated: The efficacy of any bypass technology at a project, such as bypass outfall relocation or improving fish guidance efficiency of screens at Bonneville, is a function of the potential success of alternative measures for improving survival of juvenile salmon, such as improved spill effectiveness, surface bypass development, or gas (supersaturation) abatement.

Long-Term vs. Short-Term Goals: The Corps’ program is largely focused on the short-term whereas salmon recovery requires a long-term perspective, as well. The standard sequence of proposal, study, design, and implementation (with bidding and construction schedules) is too slow and inflexible for salmon recovery.

Biodiversity: Biodiversity of salmon and steelhead stocks may not be protected by the intake screen systems in use or by other planned technologies. There is ample evidence that the collection efficiency of each bypass system varies by species, life history type and population.

Inconsistent Measures of Performance: There is a critical clash of performance measures between the upper-river salmon restoration programs and Corps mainstem passage programs. Upper river programs, such as many ESA-driven actions, employ performance criteria focused on sizes of individual stocks or spawning populations, while the hydroelectric management decisions are based on averages for all stocks combined that are weighted toward the most abundant species and stocks. It is inconsistent to protect genetic diversity of listed stocks in the watersheds, only to relax that protection in the hydroelectric system. The principle we see is the need for the common “currency” of stock specific performance for measuring performance of system improvements. Stock specific performance is the ideal standard, however technically challenging it may be to attain.

More Emphasis Needed on Adult Passage: The Corp’s capital program gives insufficient attention to adult salmon and steelhead. More attention should be given to identifying and correcting adult passage problems. The principle we see here is that the few returning adults represent the survivorship of many thousands of initial smolts and they should be given higher priority than they have in the past.

How to Schedule Salmon Recovery Measures: The question of what most needs to be done for fish passage (juvenile and adult) seems to have been slighted in deference to the on-going momentum of existing projects and funding cycles. The concept is that clear criteria based on biological needs for successful fish passage are required to do the sort of prioritization among projects over time required by the Congressional mandate. The lack of agreed technical criteria, combined with a wide diversity of opinion, both confuses the implementation of policies and leads to seemingly duplicative efforts.

Importance of Premises and Hypotheses: An explicit statement of biological premises is a valuable aid for efficient development of fish passage technologies. The premises and assumptions form testable hypotheses that clearly guide further research and development, thus reducing both simple trial-and-error approaches and the tendency to keep making relatively minor adjustments to existing technologies without a good biological basis. We advise that all projects be made to list their premises explicitly and summarize the evidence in support of those premises before construction and testing of prototypes proceeds.

Site Specificity v. General Solutions: Application of the biological principles of fish behavior and physiology has been subsumed under questions of building structures to fit the features of a particular dam. The principle here is to foster a design process that meets the generic needs of fish first and then adjusts the design to the specific characteristics of the dam secondarily. Put emphasis on commonality of purpose and function first. We suspect that a more cost-efficient process of dam modification for fish passage can result.

Diversion v. Destination: In planning bypass options, the methods of diverting smolts at dams should be separated from the destination of the fish after the dam is bypassed, as well as from the particular downstream purposes, such as transportation, the diversion might serve. The principle is that the method of diversion of smolts does not necessitate any particular destination following diversion.

The following ecosystem perspective was developed.

The Ecosystem Approach: The proposed improvements in the CRFMP falls short of an ecosystem approach that would seek to implement measures designed to maximize the proportion of migratory fish species protected. The CRFMP projects largely represent additions or replacements for technologies that have been developed to enhance the survivals of a portion of the native migratory fish species impacted by the dams. The species that is excluded from fish passage design criteria today is tomorrow’s listed species.

Biodiversity Issues: Considerations of biodiversity were almost uniformly lacking in the plans for the CRFMP projects we reviewed. The ISAB has repeatedly stressed biodiversity measures as one of the most important aspects of an ecosystem approach. The Council has identified maintenance of biodiversity as an objective in the Fish and Wildlife Program. We state and answer some critical questions we would like to see addressed as projects are conceived, designed, and prioritized for implementation.

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