SUBLETTE COUNTY – The Wyoming Water Development Commission’s two days of meetings last week pushed several important Upper Green River projects another step toward contracts and construction.
They include the a new system for a Pinedale-Boulder subdivision, the Middle Piney dam reconstruction, Fontenelle Reservoir’s riprap, a Big Sandy watershed study, cloud seeding – and rebuilding the defunct Silver Lake Dam in the Bridger Wilderness.
The meeting room was packed both days with local ranchers, legislators and scientists gathering to hear the WWDC’s updates to the Interim Joint Ag and the Select Water interim committees.
On Thursday, June 14, WWDC director Harry LaBonde described Level I, II and III projects that will focus on the Upper Green River and its tributaries. Level I describes a study phase, Level II feasibility and Level III, construction.
High Meadow Ranch
On the smaller scale, the High Meadow Ranch Water District is in the final Level III design stage to install a new well, storage tank and new and replaced pipeline for the Barger subdivision. The project appropriation is $1.99 million and the project is projected for completion in 2022.
New Fork Lake
New Fork Lake’s dam enlargement to benefit downstream irrigators is now at the Level II feasibility study with Bridger-Teton National Forest, U.S. Army Corps of Engineers, Wyoming Game and Fish, State Engineers Office and State Historic Preservation. The proposal is to rebuild the dam and lower the outlet to increase storage capacity by about 9,400 acre-feet.
LaBonde reported, “There is a chance this project could finish ahead of schedule and have a Phase III recommendation in November.”
Middle Piney Reservoir
The actual rebuilding of the Middle Piney Reservoir on Forest Service land starts this summer with a groundbreaking ceremony at 2 p.m. on Monday, July 18, according to LaBonde.
“Middle Piney Lake is a natural lake formed by a landslide,” he explained. “A permit was issued on 1919 and dam construction was finished in 1939. It’s an earthen dam built on the landslide.”
The dam has lot of seepage and if it gave way, there would be a “catastrophic failure.”
The WWDC decided to proceed with repairs due to public safety without acquiring the site from the Forest Service, he said.
The state did get a 30-year special-use permit to “put this reservoir back in place and put this water back to beneficial use,” LaBonde said.
The first stage will be to strip away part of the existing dam down into the landslide to strengthen the structure. The $12-million project is slated for completion by 2022.
The WWDC’s Big Sandy Reservoir Enlargement project is also now at Level III, to raise the spillway by 5 feet and add about 13,000 acre-feet for the Eden Valley Irrigation and Drainage District. That portion is budgeted at $8.4 million with completion in 2023.
“This is No. 2 on the governor’s list of projects,” LaBonde said.
The Big Sandy Watershed Level I Study was approved to begin next month with a $271,000 contract to Rio Verde Engineering of Pinedale in Sublette, Fremont and Sweetwater counties.
Possibly the most controversial outside the state, the WWDC’s long-sought riprap project for Fontenelle Reservoir Dam might be the winner. The Bureau of Reclamation facility holds back about 345,000 acre-feet of water; the state has two contracts for about 120,000 acre-feet of that water, leaving about 140,000 “active” acre-feet that are “unobligated,” according to LaBonde.
The state is doing its Level II feasibility study to determine how to make more of the reservoir usable. The lowest portion with the current level of riprap holds about 80,000 acre-feet that are considered “inactive.”
“The plan is to riprap it (higher up) and make it a usable part of the reservoir,” LaBonde said.
One way is to completely drain the reservoir and completely replace the riprap for an estimated $8 million. However, he said the feasibility study shows it would be detrimental to downstream users. Another option is to draw water down partly and place riprap underwater for an estimated $16.5 million.
“Armoring the lower interior face of the dam could make accessible an additional 80,000 acre-feet of storage” for water storage in case of drought. The entire process is very elaborate and expensive, with Congress needing to approve that $16.5 million and a $750,000 appropriation “just to move through the NEPA process,” he said.
Downstream Colorado River Basin compact states are upset that Wyoming is considering holding back or “banking” unobligated water and lawsuits are expected even while Fontenelle’s feasibility study continues.
The Select Water Committee, though, approved moving ahead with its own feasibility study on water banking and legislation for Wyoming.