What qualities does a good waterfall have?
An evaluation team strolled around Riverfront Park on Wednesday morning, listening to the sound of the Spokane River and rating its appearance as it cascaded over basalt bedrock.
At 10 different view points, people on the team rated the falls for the resonance of the flowing water, its depth and whitewater activity, plus how well it covered the rocks.
Opinions varied. Some observers preferred a frothy look with visible rocks. Others wanted higher flows and more of a “raging river” feel.
The work is part of an experiment by Avista Corp., whose employees are trying to figure out if they can produce better-looking falls with less water. The utility hired a consultant to set up temporary weirs to divert flows to different parts of the channel.
As a result, more water moved through the Upper Falls’ north channel on Wednesday, but the south channel’s waterfall was smaller.
“It’s robbing Peter to pay Paul,” said John Osborn, a Sierra Club representative, who liked the north channel’s look but said the improvement shouldn’t come at the cost of flows in the south channel.
That’s particularly important with the vacant YMCA building coming down, Osborn said. Riverfront Park visitors will get great views of the south channel when the building is razed and the land is incorporated into the park, he said.
Last year, Avista and the Sierra Club worked out an agreement for year-round flows over the falls as part of the relicensing of the utility’s Spokane River dams. Avista diverts part of the river through its Upper Falls hydroelectric project. During past summers, the diversions virtually dried up flows through the north channel, exposing bare rocks and green algae slicks.
The agreement calls for a baseline flow of 500 cubic feet of water per second over the Upper Falls during daylight hours – which amounts to 3,740 gallons per second.
During the time that Avista spills water for the falls, the utility forfeits the electricity to power about 975 homes, said Hugh Imhof, an Avista spokesman.
That’s why the company wants to mimic the look of 500 cubic feet of water per second with less flow. The agreement with the Sierra Club allows Avista to run tests to see if that’s possible.
Wednesday’s evaluation was part of those tests. The evaluation team included members from the Washington Department of Ecology, the Spokane Tribe, the city of Spokane, the Spokane Canoe and Kayak Club, Avista and others. The temporary weirs attempted to duplicate the effect of future channel work.
Avista officials think smaller amounts of water could make the falls look fuller if man-made canals and trenches in the riverbed were filled in. The trenches date to Spokane’s early industrial days and were used to direct the river’s flow to factories and laundries.
To alter last year’s agreement, Avista, the Department of Ecology and the Sierra Club would have to mutually agree that a smaller amount of water looked as good as or better than the 500 cubic feet per second.
The talks are occurring “in good faith,” said Rachael Paschal Osborn, a water rights attorney who represents the Sierra Club and the Center for Environmental Law and Policy. But she wasn’t confident Wednesday morning that the result could be achieved. The consultant planned to try other configurations in the afternoon. A decision won’t be made immediately.
“The river has a right to have water in it,” Paschal Osborn said. “It’s really been a long haul because we started with the idea that it’s OK for the river to be completely dry.”
The flows made a lot of difference to the experience of Riverfront Park’s visitors, said Taylor Bressler, a parks manager for the city of Spokane who participated in the evaluation.
“I was glad to hear that they were trying to create a consistent waterfall,” he said. “In the summer, when it (the north channel) isn’t running, it looks pretty desolate.”