Washington Seeks Comment on Avista Dams

Water quality in the Spokane River would be protected, and the public would see more water over Spokane Falls, under a draft "401 Water Quality Certification" released recently for public review.

The Washington Department of Ecology is taking public comment on the water-quality certification that is designed to ensure that four Avista Corp. dams do not harm water quality. The dams include the Upper Falls Dam, the Monroe Street Dam, the Nine Mile Dam, and Long Lake Dam on Lake Spokane.

The 401 certification (similar to a permit) is required before the Federal Energy and Regulatory Commission can approve Avista's license to operate the four dams in Washington. Licenses are renewed after 30 to 50 years. It refers to Section 401 of the Clean Water Act and includes ways for Avista to comply with state water-quality standards and other relevant state regulations protecting the environment.

The re-licensing process began in 2002. The state agency has been involved in the discussions with other stakeholders since that time. In consultation with the Washington Department of Fish and Wildlife, other fish agencies, tribes and the public, Avista and the agency have identified activities designed to avoid, minimize, or compensate for the effects of the dam's operation on water quality and aquatic resources.

Hydropower dams and facilities impound rivers, spill water, and change stream flows. This can alter fish habitat, increase water temperature, and increase "total dissolved gas" generated by water spilling over dams. The gas causes "gas bubble trauma" in fish.

"This draft certification is a key ingredient in a complex set of actions being taken this year to make serious progress cleaning up the river," said Jim Bellatty, who manages the agency's water quality office in Spokane. "We're comfortable that these facilities will meet our water quality standards and that Spokane River is on its way to being a cleaner, more beautiful place to play and enjoy."

Avista will have a maximum of 10 years to fulfill the requirements in the certification. This "compliance schedule" is especially important for implementing total dissolved gas control measures and evaluating the effects of flow fluctuations on the Spokane River. It includes plans to monitor, evaluate, report, and implement conditions designed to demonstrate that the dams are complying with state water-quality standards.

Another goal in the 401 Certification is to achieve the flows that residents and visitors want to see. The document contains aesthetic and minimum-flow requirements. Under the plan as written, downtown visitors and local residents will see more water flowing through the North Channel, which is currently dry for most of the summer. The increase would take place between 10 a.m. through 30 minutes after sunset.

In general, minimum flows during dry times, would increase by 200 to 300 cubic feet per second. This amounts to up to 2,244 gallons per second of increased flow.

The 401 requires Avista to do its share to increase the amount of dissolved oxygen in Lake Spokane to support a healthy fish population. Fish depend on oxygen to breathe. Avista's actions and the schedule itself will be consistent with the community's phosphorus reduction plan called Foundational Concepts. This document is included within the draft 401 Certification.

Significant water quality improvements are required before a major review is conducted in 10 years. Avista will continue to conduct computer modeling to determine the company's contribution to the dissolved oxygen deficiencies. Avista also plans to modify the structures inside Long Lake Dam to increase the dissolved oxygen that is released on the downstream side.

To view a copy of the draft 401 Water-Quality Certification, send e-mail to dman461@ecy.wa.gov.

Featured Webinar