Raising the Lost Valley Reservoir

A plan that has been in the works for decades to increase the water storage capacity at the Lost Valley Reservoir in Adams county, Idaho could be close to finally becoming realized.

The dam was built in 1910, and the hope is not only update it, but increase its height by 30 feet and triple the amount of water that can be stored there from 10,000 acre feet to 30,000 acre feet.

Verbatim

THE LOST VALLEY RESERVOIR IS NESTLED BETWEEN THE SEVEN DEVILS MOUNTAINS AND THE WEST-CENTRAL MOUNTAINS OF IDAHO JUST 5 MILES OFF HIGHWAY 95. IT’S A PRIVATE RESERVOIR THAT FEEDS THE WEISER RIVER IN BOTHS ADAMS AND WASHINGTON COUNTIES.

(Irv Leen) We're standing at the Lost Valley Dam up here at the reservoir. This is the dam that we want to get raised.

IRV LEAN IS THE VICE PRESIDENT OF THE LOST VALLEY RESERVOIR BOARD AND IS ALSO ON THE BOARD OF THE WASHINGTON COUNTY FARM BUREAU.

The dam here is way past due to be raised. It doesn't have a very good rating from the state of Idaho. I think we have a D rating or a poor rating. It's well over 100 years old.

THE SMALL EARTHEN DAM WAS BUILT BACK IN 1910 BY THE MESA ORCHARD COMPANY FOR IRRIGATION. PLANS TO RAISE THE DAM HAVE BEEN IN THE WORKS FOR DECADES.

So it started in the early 19s and then it was raised in the 30s and then raised a little bit more in the 50s.

We want to raise the dam high enough up that it will store an additional 20,000 feet behind the 10, the roughly 10,000 feet that are already stored. And that will give us a total storage of 30,000 acre feet.

THAT WOULD TRIPLE THE WATER STORAGE CAPACITY OF THE DAM.

THIS DRONE IS 30 FEET OVER THE TOP OF THE EXISTING DAM, WHICH IS HOW MUCH HIGHER THE DAM WILL HAVE TO BE TO MAKE THAT HAPPEN.

BECAUSE OF THE WATER LEVEL RISE, SOME OF THE ROADS WOULD HAVE TO MOVED TO HIGHER GROUND, AS WELL AS SOME OF THE VERY POPULAR CAMPGROUNDS SURROUNDING THE RESERVOIR. OTHER CAMPGROUNDS ARE ALREADY SET BACK FAR ENOUGH THAT THE NEW WATER LEVELS WOULD NOT AFFECT THEM.

THERE HAVE BEEN OTHER CHANGES OVER THE YEARS LIKE UPDATING THE OLD MANUAL HAND CRANK SYSTEM THAT USED TO CONTROL THE OUTLET VALVE.

PLUS SENSORS ALONG THE OUTFLOW ON LOST CREEK TO MONITOR THE LEVELS. THE WATER IS VITAL FOR AGRICULTUAL IRRIGATION DOWNSTREAM.

(Dale Barton) It's really necessary in the later part of the year. Normally on average years, we turn it in 1st of July and put about, oh, 80, 90 CFS into the river for supplemental water above the stream flow rights. And makes a big difference. It's cooler water for the river. The Weiser River gets really warm. It cools that down. It's really essential economically to the three valleys, the Council Valley, right here, just where the West Fork of the Weiser comes out with this water. And then it goes on down. There's a few rights above us, but then the next one would be the Salubria Valley around Cambridge. And then Middle Valley at Midvale.

DALE BARTON IS THE PRESIDENT OF THE LOST VALLEY RESERVOIR BOARD, HAVING FIRST JOINED BACK IN 1977.

DALE SAYS THE EXISTING OUTFLOW PIPE IS 36 INCHES WIDE, WHICH ISN’T LARGE ENOUGH FOR THEM TO MEET PEAK DEMAND DURING IRRIGATION SEASON. HE’D LIKE TO SEE THAT DOUBLED TO 6 FEET.

THE AGE OF THE DAM ITSELF IS ALSO A PROBLEM, WITH DETERIORATING CONCRETE AND WOODEN FLASH BOARDS THAT THE DAM TENDER HAS TO CHANGE MANUALLY TO ADJUST THE SPILLWAY LEVEL.

IN HIGH WATER YEARS THEY CAN END UP RELEASING A LOT OF WATER VERY EARLY THAT COULD HAVE BEEN STORED FOR IRRIGATION USE IF THEY HAD MORE CAPACITY.

(Dale Barton) The reason for raising is kind of a no-brainer. We're storing 10,000 acre feet on this watershed is all we're storing and it's an average of 27,000 acre foot that we have to release through this old archaic board, flash boards, three-foot outlet pipe. We have to handle all that runoff water in the spring and release 17 to 20,000 acre feet and more. Some years we would overfill a 30,000 acre foot reservoir on good years of snowpack. So that's the reason for raising it is so that we don't have to fight with all that runoff water with our archaic system. We've got to get updated to a new spillway, a bigger outlet works so we can deliver this water.

You've seen this spillway is probably 20 feet wide. and the new spillway is going to be, at the high level, it's going to be like 100 feet wide. So all that safety factors are built in, and that's why we're under pressure to get this done, because we'll either lose this dam as far as being able to use it, they'll take it away from us if we don't fix it, and it's kind of a no-brainer to go back in and fix the outlet works and make a bigger spillway.

THE SAFETY IMPROVEMENTS PLUS THE CAPACITY INCREASE TO 30,000 ACRE FEET WOULD ALLOW FOR BETTER FLOOD CONTROL IF THEY HAD A YEAR WHERE THE SNOWPACK MELTED VERY QUICKLY.

(Irv Leen) If we did have it all at once, we could store the 30, we could hold that water and the safety factor would be huge and we wouldn't be flooding out Council and Cambridge and Midvale and Weiser and all the rest of the towns down there.

THE ESTIMATED COST FOR THE PROJECT RIGHT NOW IS A LITTLE OVER 13 MILLION DOLLARS.

(Irv Leen) The 13 million is actually a middle of the road figure. We've been as low as 11 and as high as 17. 13 and change million is the middle of the road.

LEEN SAYS THE COST PER ACRE FOOT OF THE ADDED WATER STORAGE IS LIKELY THE LEAST EXPENSVE OF ANY PROPOSED PROJECT IN THE STATE.

 This is probably the cheapest water that there is in the state of Idaho.

AN ENVIRONMENTAL IMPACT STATEMENT IS ALSO REQUIRED, IN PART BECAUSE OF THE NORTHERN IDAHO GROUND SQUIRREL, WHICH IS LISTED AS A THREATENED SPECIES. IT ONLY LIVES IN ADAMS AND VALLEY COUNTIES.

THE FUNDING PROCESS IS COMPLICATED AND STILL IN PROCESS, WITH LOANS AND GRANTS FROM THE STATE OF IDAHO, THE IDAHO WATER RESOURCE BOARD, AND THE U.S. BUREAU OF RECLAMATION’S SMALL STORAGE GRANT PROGRAM.

THEY’VE ALSO SOLD WHAT ARES REFFERED TO AS D-SHARES, WHICH ARE RIGHTS TO THE ADDITIONAL WATER THAT THE RESERVOIR WOULD HOLD.

(Irv Leen) 13 million includes the EIS, the engineering, the construction of a whole new dam.

IF EVERYTHING GOES SMOOTHLY, CONSTRUCTION COULD START AS EARLY AS FALL 2027.

2027 fall is optimistic. It might be 2028, but A lot of it depends on the red tape that we got to go through and when we get when we get approval.

BECAUSE IRRIGATORS DEPEND ON THE WATER, THEY’RE HOPING THE MAIN CONSTRUCTION PHASE CAN BE COMPLETED WITHIN ONE YEAR, SO THERE IS NO INTERUPPTION OF THE WATER SUPPLY.

(Irv Leen) The economies of the Council Valley and the Salubria Valley and the Middle Valley, it relies so much on this water that if we were to lose this dam, this water, those areas ag-wise would dry up as far as the crops. A lot of the farmers in both 3 valleys have invested in pivots. They've gone to water saving measures. And when we sold the D shares, almost all of the water was sold right in the local 3 valleys.

Now, the benefits, cooler water for the Weiser River.  we would have cooler water for the fish. It would also keep the cooler water, would keep the moss out of the Weiser River, which would help all the people that run ditches and stuff out of that.

THE RESERVOIR IS ALSO AVAILIBLE FOR THE US FOREST SERVICE TO USE FOR FIGHTING WILDFIRES.

THERE’S ALSO BEEN CONCERNS ABOUT THE RESERVOIR STAYING PRIVATE. LEEN SAYS THE DAM ITSELF SITS ON FEDERAL GROUND, BUT THEY HAVE AN EASEMENT FOR THAT.

THEY OWN PART OF THE LAND THE RESERVOIR SITS ON, UNDERNEATH AND ON THE SIDES, PLUS WATER RIGHTS TO STORE THE WATER. HE SAYS THEY’LL BE CHECKING EVERY DOCUMENT WITH A FINE-TOOTH COMB TO MAKE SURE IT STAYS PRIVATE. 

Well, it just would alleviate a lot of the strain on dry years like we're experiencing this year.

WASHINGTON COUNTY FARM BUREAU PRESIDENT CHRIS LEVERENZ SAYS THE PROJECT ANSWERS THE NEEDS OF THE AREA WHEN IT COMES TO WATER.

(Chris Leverenze) Farm Bureau's perspective, our policy is very strong for water storage.

 This project for the farmers in the Weiser River drainage area is very beneficial. It puts a lot of less of a strain on the water that comes out of the Weiser River and Crane Creek Reservoir. improves that availability.

There always seems to be a more need for that water also not just from the farmers but from the general population as well.