Living Rivers - Colorado Riverkeeper
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LR Letter
December 4, 2002

Navajo Dam re-operations on the San Juan River

Mr. Ken Beck
Bureau of Reclamation
Western Colorado Area Office
835 East Second Avenue, Suite 400
Durango, CO 81301

Via Fax: 970-385-6539

Re: Navajo Dam Operations, Draft Environmental Impact Statement

Dear Mr. Beck

Living Rivers appreciates this opportunity to submit the following comments on the Draft Environmental Impact Statement (DEIS), Navajo Dam Operations, September 2002 (DES-02-35).

The San Juan River is one of the most dynamic ecosystems on the planet, supporting an incredible diversity of endemic plants and animals, as well as native cultures. We are quite concerned with the demise of its native fish species, but believe with proper river management, full recovery of these species is achievable.

It has been acknowledged that the two prime reasons why San Juan River native fish are endangered can be attributed to alien fish competition and the building of dams and diversions. Despite this, the DEIS provides little assurances that these impacts will be adequately addressed, such that recovery can occur. In particular, Living Rivers finds the 250/5000 alternative recommended in the DEIS to be totally unacceptable as a means to achieve this objective.

First, while the DEIS acknowledges that endangered species have yet to achieve a "positive population response" from the present flow regime, it none-the-less recommends continuing with the same regime. In fact there has been little to no benefit whatsoever to the endangered fish populations as a result of present dam operations. Since it's not working now, and the DEIS provides no evidence to ensure that it will work in future, it seems imprudent to make permanent such a flow regime. Furthermore, it seems imprudent for the DEIS to be making any recommendations at all, as the final report of the Biological Committee has yet to be issued.

Second, without recognition of the need to: increase the length of the habitat reach through effective fish passage and potential dam decommissioning; mandate mechanisms to ensure sufficient in-stream flows in light of existing and proposed diversions and climate change; and aggressively eliminate non-native fish and plant threats to the habitat, it is unlikely that full recovery of razorback sucker or Colorado pikeminnow will ever occur in the San Juan River. Failure to adequately address these critical issues, not only threatens the validity of preferred alternative, but all alternatives presented in the DEIS. The comments which follow address these deficiencies within the EIS in greater detail.

1. Truncated reach too short to enable recovery

Historic habitat for the native San Juan River fish included the spawning beds above Navajo Dam and the sections now inundated by Lake Powell reservoir. The critical habitat identified by the DEIS on the San Juan River is substantially less, the distance between Lake Powell reservoir and Navajo Dam. Furthermore, this remaining stretch is truncated even further by a number of diversion projects.

The only remaining critical habitat, of the native 320 river miles, available for fish recovery is the San Juan River which lies between Hogback Diversion Dam and the head of Lake Powell reservoir, approximately 138 miles. Included in this 138 miles, are the 57 miles of swift water at San Juan Canyon, which is documented as habitat not advantageous for the rearing of native fish. Therefore the total available habitat for fishes that once ranged throughout the San Juan River and its tributaries has been reduced 75 percent to a mere 81 miles.

The DEIS does not demonstrate how this remaining habitat is sufficient to accommodate the rearing of native fish. There are two kinds of habitat that are needed by the native fish of the San Juan River: spawning habitat and rearing habitat. It has been demonstrated that spawning habitat is available for the fish to utilize, but that rearing habitat for the hatchlings has been severely diminished, as most of the hatchlings drift into Lake Powell reservoir to be predated upon by the exotic fish. It has been suggested by aquatic biologists that historic habitat was available to the drifting hatchlings in the lower river reaches of the San Juan beyond Clay Hills and in the areas of the Colorado River mainstem.

While the preferred alternative does call for combined flows from Navajo Dam and the Animas River to drop to 500 cfs, this may not be sufficient to halt young fish from being carried down to Lake Powell reservoir, and anything lower would reduce the backwaters habitat, which is even more critical for their survival. The success being experienced with fish recovery on the Green River is largely the result of habitat length. The DEIS fails to address these restrictions on the San Juan River, or the alternatives available to correct them.

First, most of the water diversions do not allow for adult fish passage to enable spawning in the upper reaches of the remaining habitat. This includes the diversions of the Animas River, which is part of the historic habitat of the endangered San Juan River fish. And while a fish passage device has been constructed at the Hogback Diversion Dam, it has not been determined if endangered fish even utilize it.

Second, even should successful fish passage be achieved, there is no evidence that this stretch of river will be sufficient to accommodate the needs of these larval and early juvenile fish. Historically, San Juan River native fish could rely on the free-flowing Colorado through Glen Canyon to provide both rearing habitat for San Juan River native fish, and as a refuge in times when the San Juan River ran dry. Decommissioning Glen Canyon Dam would restore the historic geomorphic habitat that the fish evolved with and would also favorably increase the range and conditions of critical habitat necessary for the recovery of San Juan River native fish.

The DEIS should have: one, identify how successful fish passage will be achieved to maximize availability of the remaining habitat; two, evaluate the effects of Glen Canyon Dam on the San Juan River Basin Recovery and Implementation Program (SJRBRIP); and three, evaluate the decommissioning of Glen Canyon Dam as a legitimate alternative to restore San Juan River native fish populations.

2. Long-term operations of Navajo Dam

At least until such time as Glen Canyon Dam is decommissioned, San Juan River native fish are dependent on Navajo Dam to reduce the likelihood that the remaining habitat will run dry. The DEIS, however, makes no reference as to the impermanence of Navajo Dam, and how its decommissioning, either through dam failure, or sedimentation could effect fish recovery.

Catastrophic floods are known to occur in the drainage of the San Juan River. Navajo Dam's ability to control floods has been called into question due to unexpected piping of reservoir water through the dam's earthen structure (Bureau of Reclamation, Engineering and Research Center, Denver). Such piping has caused other earthen dams to fail, such as BuRec's Teton Dam in Idaho, which caused loss of property and loss of life. The DEIS needs to document the integrity of Navajo Dam, and how, in the event of a dam failure, it would avoid a complete loss the San Juan's remaining, and/or recovered, native fish.

For Navajo Dam to use its river outlet works for extended periods of time during the seasonally adjusted high flows, the EIS must also report on the safety concerns related to cavitation and other potential operating hazards that could occur while using these outlet works (SJRBRIP Coordination Committee Minutes of 10/15/98).

As the San Juan River erodes a geographic area that includes soft host rocks, it is no surprise that it is the major contributor of sediment for the Colorado River system. This high content of sediment poses serious concerns to Navajo Dam operations, and will eventually force the dam's decommissioning. The DEIS must outline the timeframe by which Navajo Dam will likely need to be decommissioned, and how this decommissioning will effect recovered endangered fish habitat.

3. Water quality concerns & climate change

The DEIS fails to adequately address how it will guarantee necessary in-stream flows. While historically, the San Juan River has run dry, this did not significantly affect native fish populations as they were able to seek refuge in the Colorado River. Until such time as Glen Canyon Dam is decommissioned, such refuge is not available. Therefore, BuRec must ensure water will be available for the fish. This is particularly problematic given the extent of unresolved water claims. While the DEIS recognizes the existence of such claims, and admits in particular that Navajo Nation claims, "if exercised could place in conflict most of the water in the basin," it outlines no mechanism for how the necessary in-stream flows will be guaranteed. Recent history on the Klamath and Rio Grande Rivers reveals that the Bureau of Reclamation has demonstrated an unwillingness to make such flows a priority.

Additionally, the DEIS fails to assess the likely impact climate change will have on water availability. The upcoming year, in particular, may be an eye-opener for resource managers and citizens of the San Juan River system. It is projected that even if the coming year receives normal precipitation, there will not be sufficient water supply to meet the level of demand (Personal communication, New Mexico Game and Fish, 2002.) This is indicative of the over-developed nature of the San Juan River and this issue must be more thoroughly addressed by the DEIS to produce water in times of drought for the recovery of native fish.

Recent reports issued by the US Geological Survey (USGS) specifically indicate that resource managers will have problems meeting their future water delivery projections (R. Hereford, Flagstaff and R. H. Webb, Tucson, 2002). The data indicates:

  • The 20th Century was a wetter century than normal by 20.
  • The 400-year average virgin streamflow for the Colorado River at Lee’s Ferry, Arizona totals 13.5 million acre-feet per year; 16.4 was the original projection.
  • Colorado River virgin streamflow at Lee's Ferry, Arizona can increase or decrease by as much as 35 percent.
  • High magnitude floods can stress spillway mechanisms and overflows will damage areas of development; dam failures are possible.

Climate change is becoming an increasingly important issue affecting surface water management, thus it's surprising, in light of the above, that the DEIS did not address it.

The preferred alternative will only work when climate behaves normally and would fail in a severe and sustained drought. The DEIS should have provided the total amount of acre-feet required to conserve native fish species for each alternative, and how this relates to the natural annual flow of the Colorado River. It should have also provided adjusted streamflow statistics on the consequences of climate change. Such analysis is imperative to properly manage the San Juan River and the conservation goals as outlined by the DEIS.

Lastly, the DEIS did acknowledged water supply constraints in its analysis of the 500/5000 Alternative, stating that it would not be technically feasible to implement due to present diversions. The DEIS failed to state, however, how such an alternative would in fact be of much greater benefit to the native fish, only that it is not feasible. The DEIS did not discuss opportunities for purchasing, transferring or otherwise acquiring the necessary water rights to enable the implementation of this more beneficial alternative.

To be credible, the DEIS should have developed an alternative based on the water needs of the native fish, then determined how to ensure the water availability and flow regimes that will best provide ensure such water is provided on a permanent basis.

4. Insufficient high flows

The maximum flows outlined in the preferred alternative are not sufficient to meet the needs of the razorback sucker. This fish responds very well to spikes in the hydrogragh, but the DEIS ruled out flows above 5,000 cfs from Navajo Dam due to the technical constraints associated with the dam's river outlet works. As stated in the Flow Recommendations for the San Juan River, prior to Navajo Dam, spring spike flows of 33,000 cfs occurred at Bluff Utah, 30 percent of the time. However, the preferred alternative will not allow for such spikes. The preferred alternative is based on a calculation of the average spike flow, yet provides no analysis to demonstrate that such a flow is indeed sufficient to invoke the types of benefits necessary for the razorback sucker. Therefore, similar to the need to make necessary engineering modifications to allow for fish passage, the DEIS should have addressed more completely the benefits to razorback sucker recovery associated with higher and more consistent spike flows from Navajo Dam.

5. Removal of alien fish

It is well documented that the introduction of alien fish species has contributed significantly to the decline of the native fish populations in the San Juan River. Members of the Desert Fishes Council have specifically documented their concerns about alien fish impacts on the available resources of food and habitat in our desert rivers (Battle Against Extinction, W. L. Minckley, 1991).

Every alternative presented supports the continued existence of an artificial trout fishery. These fish should be removed because they significantly compromise native fish recovery goals—feeding on the larval and early juvenile native fish. Sport fishermen have alternative venues to pursue their recreation, some nearby where trout are a natural feature of river ecosystems. The native fish do not have such alternatives and are forced to compete for survival in an impossible coexistence. Other alien fish species, such as stripers, catfish and carp, too must be eliminated as opposed to the proposed suppression strategies.

6. Removal of alien plant species

Invasive tree species such as tamarisk and Russian olive need to be more aggressively mitigated with programs other than the mimicry of the natural hydrograph called for in the DEIS. These trees have dramatically changed the geomorphology of river bed, which alters the optimal productivity of the spawning habitat for the endangered fish, as well as the habitat of the endangered birds and some species of special concern. These exotic plants should be eliminated and replaced by native vegetation such as cottonwood and willow.

7. Water quality

The DEIS does not sufficiently address how water quality will be improved such that there will no longer be impacts on native fish. The health of San Juan River native fish is presently being compromised by oxygen sags, lesions from toxic chemicals associated with the production of petroleum products and sewage treatment plants.

This situation is anticipated to worsen as new projects and diversions come on-line. Pollution and heavy metals from return flows will increase, suppressing further native fish productivity. Increased selenium in the soil systems of the drainage is of particular concern, as it is known to shunt the reproduction organs of the endangered fish. Moreover, in the summer of 2001, BuRec published The Low Flow Test: San Juan River, which concluded that the reoperation of Navajo Dam, as called for in the preferred alternative, would not meet New Mexico water quality standards over the long-term.

The DEIS claims that BuRec plans to address these matters through dilution by the recommended flows. However, such flows are already being implemented, and water quality standards continue to be violated. Clearly, this is not a viable solution in the near or long-term. While the DEIS also states that efforts will be made to increase enforcement of non-point source pollutants, it provides no details of how this will occur and how this will necessarily benefit water quality.

8. Water management

The constraints facing the recovery of San Juan River native fish are indicative of a much greater disaster in years to come. The over allocation of the river, unresolved water rights claims combined with lower water volumes due to climate change will lead to extensive conflicts and a dried-up river with regularity. There will be no recovered fish, or water for many of the users that presently have rights. Surprisingly, however, BuRec is doing nothing to resolve this.

In addition to the comments pertaining to water quantity in item 3 above, BuRec must comprehensively address how water from the San Juan River basin will be allocated in such a way that the needs of native fish will not be compromised. BuRec must identify what mandated water conservation and water utilization policies will be enforced on all users to sufficiently reduce their take from the river to eliminate the likelihood of shortages, both for native fish and water users. Such policies will not only resolve many existing and future problems, but save money by eliminating the need for some of the basin's existing and proposed projects.


Living Rivers has no confidence in the conclusions of the DEIS or any of its alternatives to successfully recover the native fish of the San Juan River. The preferred alternative represents the continuation of present operations, which has yet to demonstrate any results. Additionally, before any alternative can be adequately considered, the DEIS must be significantly expanded to address the likelihood that the current habitat is too short in length to allow for recovery, and alternatives explored to remedy this. The DEIS must also address specific mechanisms to maintain in-stream flows in light of present and anticipated demands on the system, climate change, and the prospect of Navajo Dam failure and eventual decommissioning. The removal of non-native fish and plant species must become a higher priority, as should improvements in water quality.

Alternatives, which may be more beneficial to recovery, such as the 500/5000 Alternative must not be excluded merely because of water constraints. BuRec should identify what's best for the native fish, then determine how to attain it, such as mandated water conservation and acquisition of water rights for the fish. Lastly, BuRec must face the reality that the San Juan is going to regularly run out of water if new water conservation, allocation and management policies are not swiftly implemented.

Sincerely yours,

John Weisheit
Conservation Director

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