Spokane River test seeks to restore beauty to downtown falls   

Tags: Avista Utilities, Environment, Hydro power, Spokane River, Washington

Group reviewing Spokane River work.
The evaluation team takes a look at the river from one of 10 public viewpoints Wednesday morning,
August 25. The group will suggest changes to the temporary dams and come back for a second and
possibly third look at spills through the two channels. Evaluators include representatives of Spokane Parks
and Recreation, Spokane Canoe and Kayak Club, Sierra Club, Washington Department of Ecology, Center
for Environmental Law and Policy, Avista, Friends of the Falls, and others.
Normally at this time of the year, the north and middle channels of the Spokane River in downtown Spokane, what many of us know as Spokane Falls, look pretty dry. That’s because in the past during the dry summer months, natural conditions and Avista’s hydropower operations have resulted in little or no flow through that part of the river. That all changed last year with the issuance of Avista’s new 50-year Federal Energy Regulatory license to operate our Spokane River Project, which includes Upper Falls and Monroe Street Dams in downtown Spokane. As a result of the relicensing process, we must now release minimum aesthetic spills around the clock at both Upper Falls and Monroe Street. That began this summer, and you may have noticed more water flowing through the falls in July and early August.

Spokane River during test
But there’s more to it than that. If you’ve been to Riverfront Park in the past couple of weeks, you’ve probably noticed something else in the river. Cranes, sandbags, and workers have been busy preparing for an aesthetic spills pilot test at Upper Falls Dam. This test will help us determine whether permanent channel modifications can be made to bring the riverbed closer to its natural state, the way it was before early developers in Spokane cut into the bedrock to divert the water during dry times.  We’re hoping to enhance aesthetic appeal even more during periods of low river flow. Our license requires us to do this study to learn whether the same, or a better, aesthetic effect can achieved with daytime releases of 300cfs and channel modifications, as the current daytime release of 500 cfs does, without modifications.

Avista’s Upper Falls Dam is located where the river splits into two channels around Havermale Island in Riverfront Park. The southernmost channel forms the forebay that provides water to the powerhouse, and the northern channel passes through the control works dam and splits again into two smaller channels that run north and south of Canada Island. These are referred to as the north and south (or middle) channels. These two channels are where the pilot test is occurring, and we hope that as a result of this work, viewers of the river downtown will have a pleasant experience no matter what time of year it is.

Last week we temporarily interrupted normal aesthetic spills and placed several small, temporary dams made with sandbags, called weirs, throughout the channels. These weirs divert the flow of water throughout the channels, and this week, an evaluation team made up of representatives of stakeholders, agencies and the public is viewing test spills and giving their feedback as we release 300 cfs through the two channels. Team members will make judgments based on their sense of sound, coverage, depth and power of the water as it moves through the channels. The feedback we receive will help us determine whether to move forward with permanent channel modifications next year.

Next week, we’ll remove all of the equipment and materials from the river, and we’ll return to normal aesthetic spills the following week. Then, if the outcome of the pilot test shows us that permanent modifications are the way to go, the real work begins.

So far, we’re excited about the potential of this project. We’re hoping the result is a cascading waterfall effect throughout both channels of the river that visitors and the community can enjoy all summer long. And this collaborative effort could indeed accomplish that, possibly restoring at least some of the river’s natural beauty that was lost through the development of Spokane over the past 100 or more years.
Posted by  System Account  on  8/25/2010
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