GREEN RIVER - Most residents refer to it as "alkali flats" - the sandy white, dusty flats located at the west entrance to the city that meanders along both sides of the Green River.

But old-timers remember when the area turned into a lush, green wetlands each spring.

The high runoff used to channel some of the river's flows through a series of oxbows and channels - known as the Killdeer wetlands - that sit beneath the Palisades and Tollgate Rock formation made famous by the paintings of Thomas Moran.

The wetlands drew migratory birds, big-game animals and native fish species among other wildlife to this small city in central Sweetwater County in southwest Wyoming.

But progress - in the form of the construction of the Fontenelle Dam and Reservoir about 40 miles upstream in 1966 - ended the annual flooding cycle, as the dam regulated flows on the river.

Those old days are about to return, thanks to the work of a city group formed nearly two decades ago to promote the development of a greenbelt along the banks of the Green River as it winds its way through the downtown area.

The city's Greenbelt Task Force has been working since 1991 on the Killdeer Wetlands Intake and Restoration Project.

The project aims to restore the approximately 45-acre wetland area to its historic state, officials involved in the effort said during a tour of the wetlands Friday morning.

City officials said when the approximately $650,000 project is completed next year, about 85 percent of the historic oxbows, pools and islands that comprise the Killdeer wetlands should return each season.

"What we've been seeing this spring (with the unusually heavy runoff) … is what we want the wetlands to look like on a regular basis," said Gary Wolfe, chairman of the seven-member Greenbelt Task Force.

"This is an ambitious … showcase project," he said.

Officials said the proposed project will provide a significant benefit to residents, including the enhancement of the greenbelt west of the Union Pacific Railroad bridge.

It will also spur the restoration of plant diversity in the Green River corridor, provide additional habitat for birds and aquatic species, and perhaps become a destination for hikers and whitewater enthusiasts.

Officials noted the restored wetlands should make for some great viewing for residents and tourists from the city's new chamber of commerce visitors center, which will perch on a bluff to the east overlooking the wetlands.

"This is going to be quite a remarkable endeavor for us … and we're excited to get this completed next year," Green River Mayor Hank Castillon said during a meeting with the various state, county and federal agencies involved in the project.

The wetlands project will also complement ongoing river recreation-related efforts by the greenbelt group, including the greenbelt walkway and the city's whitewater kayaking park.

Master plan

The Killdeer wetlands area was identified in a 1991 greenbelt master plan as an area where plant diversity that was lost with the construction of the Fontenelle Dam could be restored.

A greenbelt project was completed in 1996 that was intended to continuously feed water to the wetlands, Wolfe said. The original project garnered public support and grant funding was obtained through the Central Utah Project Completion Act.

The city received U.S. Army Corps of Engineers and other permits for the diversion of about 5 cubic feet per second of water - during the river's high flow period - to the wetlands through the construction of an intake structure, ditch grading and a dam and outlet structure.

The project was intended to provide a shallow lake ranging from 4 to 6 feet deep across the 45 acres. But a decade of drought conditions in the region kept down the normally high flows and the wetlands never filled.

When high flows resumed two years ago, the project ran into problems, as it failed to function as originally intended, Wolfe said.

Sediment accumulation, river bed scour and a leaking outlet structure could not maintain the pool needed for the wetland, he said.

Last year, an engineering firm designed a reconstruction plan for the wetlands system that officials hope will function much better over a variety of weather and flow conditions.

"We think the earthwork repair of the dikes … will function much better than the old staked log structure did," Wolfe said.

Construction will be done in two phases, according to plans. A rock sill will be constructed part way in the river for the intake structure as part of this year's phase.

Contact southwest Wyoming bureau reporter Jeff Gearino at 307-875-5359 or gearino@tribcsp.com