Moses Lake Irrigation District expresses 'alarm' over feed route

MOSES LAKE — The Moses Lake Irrigation District is expressing concern over the possible impacts of increased water flows through an area creek to Potholes Reservoir.

The district submitted a letter of protest for public comment to the U.S. Bureau of Reclamation regarding its draft environmental assessment of a suggested alternative water route into the reservoir.

The bureau's selected alternative would release water from Billy Clapp Reservoir into Brook Lake and convey it down Crab Creek to Potholes Reservoir, taking about 25 percent from an existing route to the reservoir.

Public comment deadline was Sunday. The bureau held a public meeting May 16.

As the district followed the process of the bureau's study, and the study entered its draft assessment stage, the irrigation district became even more concerned and alarmed, consultant Don Beckley said.

An environmental impact statement lists concerns about sedimentation, aquatic weed infiltration and the impact to Moses Lake, Beckley said. The bureau-issued studies show "minor" amounts of sediment transported through the system and no modifications of the creek are anticipated for erosion protection, he said.

With the preferred alternative, a continuous release of about 100 cubic feet per second would deliver an additional 4,171 tons of sediment annually into Moses Lake, bureau Special Projects Manager Jim Blanchard said. A second scenario, putting in 650 cubic feet per second for approximately three months would put about 5,432 tons of sediment through.

Beckley said those amounts are estimated to be nearly 500 truckloads of sediment dumped annually into the lake, at 10 tons per load on a dump truck. The new sediment would join the sediment already in the lake, and be continually added for as long as the system remains in place.

Agencies disagree about the impact of sediment, Beckley added.

Some fish and recreation agencies see it as an undesirable, which would create additional weed seabeds.

Other entities see the sediment as a good thing, designating portions of Moses Lake as special aquatic sites and emerging wetlands.

"The issue here is they said sedimentation was not a problem and 5,000 tons will be forthcoming," Beckley said. "From our vantage point as to maintenance and rehabilitation of the lake as sediment fills it up, and we continue to try to keep it relatively clean, clear, enjoyable as opposed to an algae-based stagnant pond, we're caught in the conflict of what is good and what is bad."

Blanchard said sedimentation survey work was done specifically because of the questions about the alternative route. A range of roughly 4,600 to 5,200 tons of sediment would go into Moses Lake, he said.

"What we don't know because we didn't study is how much of that would go on through Moses Lake because we also put a fairly large amount of extremely clean water through the lake through the other route, so we can't really say what the total accumulative effect would be," Blanchard said.

Blanchard said the current load into Moses Lake and by what percentage it would increase is unknown.

Blanchard said the bureau did not look at the impact to Moses Lake or the areas below the lake.

"We certainly attempted to contact the people we knew the water would have the potential of affecting their land ownership," he said. "We were looking at the impacts to the creek where the new water would be running. Below Rocky Coulee Wasteway, it would be precisely the same amount of water already going down there; we'll just move some of it at a different route. We don't see additional or different impacts to Moses Lake itself."

Beckley said the bureau's plan of study did not list cities, the irrigation district or the Grant County Mosquito Control District, from the outset, entities which would be impacted by the new route.

"This is more of a rural farm problem of getting the water from the north end to the south end for the south farmers, but none of the urban people were particularly represented in that context," Beckley said.

District Manager Curt Carpenter and concerned property owner Dan Bator addressed members of the Moses Lake City Council May 22. Council members issued a letter of protest due to lack of information and lack of notification for the study.

Blanchard said the mosquito control district contacted the bureau with concerns about eggs in the dry creek beds during bureau testing last fall.

Mosquito control district Clerk-Manager Jim Thompson said the alternative route would create more wetlands, which creates more mosquitoes, which requires more spraying.

Thompson said he got the bulk of his information about the route via the Internet and other people, although he did call the bureau last summer to ask what their plans were and was told about the routes.

Thompson said he would like an alternative through the Frenchman Wasteway reviewed further, because it would possibly help the mosquito control district.

"The Crab Creek one will generate much more wetlands, and the Frenchman would just make the lakes larger there, which negates mosquito production," he said.

Thompson said last week he would probably make a comment on behalf of the district to the bureau.

With the deadline for public comment past, Blanchard said the bureau is formulating answers to comments made, potentially modifying preferred alternatives and discussions within the environmental assessment.

"Then we will produce a final environmental assessment and a finding of no significant impact, and we hope to do that by mid-July," Blanchard said.

Carpenter said the district is not against the concept of the route, but would like to see concerns addressed. Flows coming into the lake benefit temperatures and water quality.

"It's the fact of what's coming with it and the means of mitigation," he said. "We're well aware we are a reservoir and one of our main purposes is to maintain capacity as a reservoir, and we're in full support of the farmers."