Current Topics and Issues
Frequently Asked Questions:
|
|
|
| How do Corps projects affect dissolved gas and state water quality standards? | State standards for dissolved gas in the river are 110% and were exceeded long before the dams were built by virtue of cascading water. In a normal, or average, flow year, if all of the river flow could go through the dams without operating for listed species, gas standards would not be exceeded. In a high flow year, some water would be spilled involuntarily because flows would exceed the capacity of the Corps facilities, causing total dissolved gas levels to rise above 110%. However, in order to meet the NMFS Biological Opinion objectives, the Corps voluntarily spills water up to 120% TDG to improve juvenile fish passage. For water temperature, the dams cause a temporal shift so the river warms up later in the spring and cools down more slowly in the late summer and fall. |
| Do all private and public dams in the Columbia/Snake River system also conform to state water quality standards and CWA requirements? | Not at this time. To be optimally effective, it makes sense that the region's dams all be part of the equation to ensure that the problem and solution are not worked in a piecemeal fashion. The interplay of the rivers and their tributaries is such that what happens at one dam affects the others. That is why fish recovery and clean water actions must be viewed through a system operations approach. |
| How has the project changed from the proposal contained in the January 2003 final supplemental? | In the Final Supplemental Integrated Feasibility Report and Environmental Impact Statement, the Corps selected the environmentally preferred alternative as its recommended plan. However, due to the conditions the states of Oregon and Washington have placed on the construction activities, the Corps modified that plan, therefore we will not proceed with construction of the Lois-Mott and Miller-Pillar ecosystem restoration features, and instead will transport the materials for those two sites to the ocean for disposal. Additionally, the embayment portion of the Martin Island mitigation site will not be constructed. |
| How soon can the Corps begin construction work on the project? | Work on the one or two ecosystem restoration features will begin as soon as the Project Cooperation Agreement is executed; construction probably can begin this spring, and dredging of the navigation channel will begin summer 2005. |
| Does the spill for fish called for in the NMFS Bi-Op violate Clean Water Act requirements? | Spill for fish puts the two objectives of meeting ESA and CWA at odds with each other in some cases. For example, the NMFS Bi-OP requires spring and summer spill to 120%, an amount that exceeds Clean Water Act and state water quality standards of 110%. Variances, or waivers from having to meet the 110% standard is usually requested, though not always granted, from the states of Oregon, Idaho and Washington. |
| What happens when a project's hydroelectric facilities can't handle the amount of water coming down the river during a high water year or during periods of Bi-Op required flow augmentation? | Whatever water comes into run-of-river projects must be passed, either through the turbines or over the spillway since Columbia-Snake dams have little or no storage capacity to hold water. This involuntary spill occurs when the powerhouses at each dam can't handle all the water and the excess must be spilled. In contrast, voluntary spill happens in order to meet ESA requirements for cooling river temperatures and augmenting flows to aid fish migration. |
| What effects do Corps reservoirs have on water temperature and fish in the Snake River? | The water coming into the Snake and Columbia from surrounding states is already warmed because of irrigation, logging, grazing, and pollution and development. Corps reservoirs can affect river temperatures further by shifting the temperature regime, holding more warm water later in the season. While slack water reservoirs are indeed part of the temperature problem, the detrimental effects of other contributing factors must also be addressed in seeking permanent solutions to improving water quality. |
| How is Dworshak Dam in Idaho used to help lower temperatures in the Snake River? | Releases from Dworshak, which average 48 to 50 degrees Fahrenheit cool the temperatures of the Snake River in the summertime. These selective withdrawals of cooler water, from various layers in the 700-foot reservoir, can typically only affect temperatures for a short distance in the North Fork and in the Clearwater River. Lesser impact is seen in the main stem of the Snake River. Last year, water temperature reductions of up to 2 degrees Fahrenheit were attributable to Dworshak and observed in the lower Snake River below Lower Granite dam. The benefits from the release of cool water also depend on the ambient temperature and the relative proportion of cool and warm waters involved. |
| Can you meet the dissolved gas standards of the CWA and state water quality requirements and not those for temperature? | We expect to meet TDG standards most of the time except for operating for ESA reasons or under high river flow conditions. Water temperatures may be exceeded because of the multiple ecozone* influences in the Columbia Basin.
*The high plateau portion of the river bed in eastern Washington is exposed to very warm continental air masses with high air and water temperatures, Tributary streams on the east side of the Cascades also tend to have natural conditions that naturally exceed state water temperatures standards during the summer. Tributary streams west of the Cascades also could naturally exceed state standards, but to a lesser degree and frequency during the summer. |
|
What actions is the Corps of Engineers taking to monitor temperature and gas in the river system? |
Both physical and biological monitoring is underway. The Corps has 29 stations; BOR and PUDs also have stations. Access to the hourly measurements is available to the general public. Monitoring stations above and below the dams measure total dissolved gas levels. Some are maintained year round, others primarily during fish passage season. The Fish Passage Center also samples fish for visible signs of Gas Bubble Trauma at selected locations on the Columbia and Snake rivers. They report their findings to fish agencies that determine level of criticality of fish conditions. |
|
Will the Corps modify the dams to decrease the amount of dissolved gas? |
The Corps has installed flow deflectors, or flip lip structures, to reduce dissolved gas levels on Columbia-Snake river mainstem dams. They work by preventing the spilled water from plunging deep into the water downstream of the dam, thereby reducing the amount of pressure to which the dissolved gas is exposed. |
|
What kind of studies are currently underway on gas or temperature? |
The Corps has just completed the draft final, Phase II, of the Dissolved Gas Abatement report and sent it out for review. Ongoing gas abatement studies attempt to determine the best alternatives, efficiencies and costs to change structures and operations at the dams to reduce gas levels.<br><br> The Corps is also working with BPA and Reclamation on a basin-wide water quality plan. The purpose of the plan is to look at TDG and water temperatures in the mainstem Columbia/Snake and is further described in Appendix B of the NMFS BiOp. Implementation of such a plan should complement actions being taken by EPA, states, and tribes in the development of Total Maximum Daily Load for total dissolved gas and temperature in the Columbia and Snake. |
|
How will this response affect the Corps' Lower Snake River Juvenile Salmon Migration Feasibility Report and Environmental Impact Statement process? |
The Record of Consultation and Statement of Decision released this week sets forth operations for the Federal Columbia River Power System, including Snake River projects. Although the actions spelled out in the Record of Consultation and Statement of Decision will be considered in the final FR/EIS it does not interfere with the LSRJSMFR/EIS. That process is a separate NEPA action. The Corps is now processing the considerable volume of comments received and is analyzing the substantive issues raised. The information and measures called for in the National Marine Fisheries Service and the U.S. Fish and Wildlife Service 2000 Biological Opinions are definitely factors in the Corps' choice of a preferred alternative in the final EIS. It is premature to comment on the potential conclusions of the FR/EIS at this time. It is anticipated that the final LSR FR/EIS, with a preferred alternative, will be completed in 2001. |