June flooding reiterates importance of riparian protections

Valley Creek in Stanley, Idaho, overflows its banks following heavy rains late last weeek. This spring's flooding reiterates a recent withdraw of an Army Corps of Engineers permit application to fill wetland areas along Valley Creek to make way for further development of home sites in sensitive riparian areas. (Photo by Gary Gadwa)

When heavy rainfall combined with warming temperatures across central Idaho late last week, the Gem State’s rivers offered a reminder that flooding is a matter of when, not if, and put an exclamation point on a recent U.S. Army Corps of Engineers permit withdraw in Stanley.

Flooding in Stanley on May 24, 1956, is considered to have been indicative of the 50-year flood. (Photo courtesy of the Sawtooth Interpretive and Historical Association)

On Friday afternoon, June 4, the National Weather Service issued flash flood warnings for Thompson Creek, the Yankee Fork of the Salmon River and Valley Creek, all upper Salmon River tributaries near Stanley. By early Saturday morning, the upper Salmon crested at close to 8,000 cubic feet per second, more than double the day’s 80-year average of 3,200 cfs, according to the U.S. Geological Survey.

Flooding last weekend near the confluence of Valley Creek with the Salmon River was alleviated by a dike built along Valley Creek. Though not as high as the 1956 flood, it was nevertheless close. (Photo by Gary Gadwa)

In Stanley, where Valley Creek meanders eastward and slithers through the northern outskirts of town, stream bank willows were submerged as the water filled the valley and crept to the doorsteps of several new homes, part of a controversial half-developed subdivision called Stanley Sawtooth Estates.

A project by Boise-based The Hosac Co., Stanley Sawtooth Estates applied to the Army Corps of Engineers February 2008 for a permit to fill portions of the wetlands along Valley Creek in order to develop more home sites. In January 2009, however, the Corps withdrew The Hosac Co.’s application, citing the need for further study and examination of alternatives.

The decision effectively squashed the developer’s plans to build homes in the floodplain on the willow-covered valley floor surrounding the creek — for now.

“Floodplain development of this nature is problematic,” said Kevin Lewis, Idaho Rivers United conservation program director. “The Corps withdraw of the fill permit creates clear winners. They are the fish and wildlife species that depend on Valley Creek and its lush riparian habitat for their survival. Last week’s flooding clearly shows the Corps’ action was appropriate.”

In August 2008, Idaho Rivers United Board President Andy Munter testified at a Corps hearing in Stanley. Munter disagreed with some of the Corps’ assessments on the possible project impacts on federally listed endangered salmon, steelhead and bull trout.

“If you adversely affect critical habitat you’re likely to adversely affect fish,” Munter said.

In withdrawing The Hosac Co.’s permit in January 2009, the Corps specified that the company may reapply in the future if it provides requested additional information. That unfortunately leaves the window cracked to an ill-advised development that would prove detrimental to important fish and wildlife habitat.

Longtime Stanley resident and retired Idaho Department of Fish and Game Conservation Officer Gary Gadwa said he is opposed to further development along Valley Creek. Last week’s flooding was less than Stanley experienced in 1956, an event considered to be the 50-year flood, he said.

“I’ve been here since 1979, and I’ve seen it flood so many times,” Gadwa said. “This wasn’t the 50-year flood, but it could have been the 10- or 20-year event.”

Gadwa congratulated the city of Stanley for passing a floodplain ordinance this past spring and added that he hopes the city will further consider an ordinance that protects the city’s sensitive riparian areas.