New Fork Lake Irrigation District moves through Phase 2

Published on Feb. 22, 2020

Sublette County – Two summers with little or no water to irrigate hayfields, fill livestock ponds or keep gardens green?

            The New Fork Lake Irrigation District board and irrigator-members pondered that depressing scenario at their public meeting on Feb. 12, after hearing updates from state water officials. 

            Board members present were Sue Briggs Stanfill, Dave Noble, Tina Nelson, Zack Noble and Madeleine Murdock.

            State Project Manager Andrew Linch, RJH Consultants’ Bob Huzjak and Pinedale District Ranger Rob Hoelscher presented updates as the rehabilitation project moves forward to a year of hard design and environmental analyses. 

            The permitted reservoir is on the Bridger-Teton National Forest. The river’s headwaters start southeast of the Upper Green River, which it joins between Boulder and Marbleton.

             “The goal is to finish the environmental assessment this year or early next and then start the final design,” said Wyoming Water Development Office Project Manager Andrew Linch. “It is likely a two-year construction.”

            The New Fork Lake Dam Modification Level II, Phase II draft report is open for comments through the Wyoming Water Development Office. It will then be finalized, and on March 26, the New Fork Lake public scoping process will open per National Environmental Protection Act processes with a public meeting in Pinedale. 

            Two years of study have cost about $700,000, according to Linch.

Modeled results

            Huzjak presented computer modeling results after evaluating many scenarios to reach the conclusions he presented to the New Fork Irrigation District, which is partnering with the Water Development Office. 

            In 2014, the district approached the office about dam repairs and storage, with RJH Consultants hired to study increasing water storage while repairing or replacing the 1930s-era New Fork Lake Dam, to increase downstream irrigation, recreation and public safety.

            The dam currently holds back 20,340 acre-feet but only 18,500 acre-feet are accessible due to its construction. The old outlet is too high to access the lower water and should be lowered 11 feet, they said. 

            Modeling shows annual water shortages average about 6,100 acre-feet a year for land that is currently irrigated. If all permitted land were irrigated, the average annual shortage would be about 18,300 acre-feet.

            Huzjak said he would review the designs with more operational details and wrap up any issues before the formal NEPA process.

Findings

            Linch and Huzjak said the preferred option is to repair and reinforce certain parts of the dam, level out land around it, construct modern safety features and install a new outlet system for dryer years – the most practical and economical solution.

            The spillway will probably be replaced and concrete pools can slow water coming out of the dam or over the spillway. A higher bar called the Narrows could be lowered and there are actually two lakes, one four feet higher than the other.

            In 2018 dollars, the total project design and construction costs were estimated at $11.44 million, which is $1.3 million less than estimated in Phase 1. This does not include Forest Service fees.

            Huzjak said the district’s best financing option is a 91.2 percent grant and 8.8 percent loan. 

            “That pushes the cost of water to $4.84 for New Fork irrigators, who have paid $1.50 per share for the past 50 years,” Dave Noble said.

            “That $4.84 will seem like a bargain in 50 years,” said Zack Noble.

            Noble scuba-dives down to the outlet to clear trash and voiced safety concerns for himself and people on the lake.

            “The current dam makes a giant whirlpool at the outlet pipe. We’ve seen people fishing over that whirlpool. It’s scary. I’ve gone down there with saws and flashlights,” Noble said. “A few times, I’ve come home and thought, ‘Well, I’m still here.’”

            Huzjak said a larger opening would slow outgoing water’s velocity and the Forest Service wants a larger trash rack and upstream shutoff.

Construction

            Actual construction could start in 2022 at the extreme earliest, Huzjak said, but 2024 is more likely because of the extensive engineering, design and preparation work, along with required federal permitting. 

            Hoelscher said his office has “a lot of complicated laws to wade through.”

            Also, the Forest Service will require a processing fee for National Environmental Protection Agency (NEPA) analyses of fisheries, sensitive species, a tiny wetland, paleontology, aquatic resources, water quality, cultural sites, even wildlife migration.

            “That would be short-term with the construction,” Huzjak said. 

            The cultural survey revealed three new and five isolated finds not eligible for the National Register of Historic Places and the State Historic Preservation Office accepted the consultant’s report.

Slow trickle

            When construction begins, the board and public were told the New Fork’s irrigation water might trickle to nothing for as long as two years.

            “There are going to be major impacts to our district with two-year construction,” Noble said. “We better start figuring out how to survive those two years. It’s going to be extremely hard to survive. Maybe build roads one year and concentrate on the dam the second? So we’re not out of water for two years – that’s something to be prepared for.”

            Huzjak said he could build in some release. 

            “The best time to start construction is spring but we use the water then. The shortest period is the best for everyone,” said Huziak.

            Stanfill said several people have commented that when the district begins releasing irrigation water, the ground and weather are still too cold to grow much.

            “When the water goes on, it goes to everyone,” Stanfill said. “When people stop irrigating in one area, it affects the rest of us downstream.”

On the bright side

            The 2020 outlook for plenty of water is very good in the New Fork Watershed and Upper Green River Basin as a whole, according to Jeff Davis, water commissioner from the State Engineer’s Office.

            Thirty satellite units were installed last summer with two at New Fork Lake and the river, so his wireless reliability is greatly improved to record and display ups and downs online.

            In 2019, 23,216 acre-feet of water ran through the station below the dam, close to the previous year.

            “It was a good management year,” he said. “It stayed at a high level for a long time.”

Snotel reports show the local mountains are sitting pretty good for snow, Davis added.

            “Today it was about 114 percent of normal,” said Davis. “Basin-wide, for the Upper Green, it’s 133 percent. We really are getting into a good snow season; it’s looking really good.”

            Board Member Zack Noble said having satellite information about the lake’s level would save actually driving up to the dam to look at it. Davis said he could adjust his system to help the irrigation district manage its operations.

            Anyone with questions or comments about the New Fork Lake Dam Project’s Phase 2 draft report should contact a board member or Andrew Linch at 307-777-7626.

            Joy Ufford is a corresponding writer for the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.