The final phase of upgrades at the Chester Dam on the Henry's Fork of the Snake River in Fremont County will get under way this winter.
Fall River Electric Cooperative has won Federal Energy Regulatory Commission approval to install a rubber dam atop the existing concrete diversion structure.
The joint venture with the Fremont-Madison Irrigation District was licensed by FERC in 2008. Fall River Electric said the rubber dam will increase the upstream level of the river and improve flow through the dam's three turbines.
"When fully completed next spring, this hydro facility will produce approximately 4 percent of the total electric needs of our co-op customers," said Fall River General Manager Bryan Case. "The improvements will bring the coop's overall hydro production to nearly 15 percent of its system requirements."
In addition to power generation, the new Chester Dam is designed to improve the Henry's Fork fishery. It includes the installation of a fish ladder to allow safe fish movement over the dam and downstream past the dam.
Work was scheduled to begin this week and should be complete by Feb. 24, 2014.