Recovering the Big Wood River

As debate ramps up over the future of the Big Wood River following last spring’s severe flooding, fisheries scientist Russ Thurow wants Blaine County residents to use history as a guide. He wants them to understand the historical potential of its trout fishery.

Thurow, who works at the U.S. Forest Service’s Rocky Mountain Research Station in Boise, said that decades ago, the river was capable of producing larger and more abundant fish. As human development along the river increased dramatically from the 1970s onward, the riverside habitat has declined.

As a result, the fish have shrunk in size and number, Thurow said. Ask a fisherman: A good day on the Big Wood now might net a 3-pound rainbow trout. In the 1950s, the river could reliably produce fish that weighed four times that, Thurow said.

“What we have now is a fraction of what that was,” Thurow said in an interview Dec. 21. “We’ve had a loss in the Big Wood since the ’40s. Historically, the Big Wood was a remarkable fishery.”

In a 2006 study using land-use maps, the Hailey-based Wood River Land Trust calculated the loss of riparian habitat along the river from 1943 to 2004. The river lost 25 percent of habitat over that time period, though it also lost habitat prior to 1943, the study reported. From the Warm Springs confluence to a point south of Bellevue, 40 percent of the riverbanks were hardened by riprap or levees. In 2006, the Big Wood had lost 1.69 miles of river length due to channel straightening, the study reported.

Furthermore, Thurow said fish habitat on the Big Wood lacks the complexity it once had. Historically, the river featured greater diversity of insect life, as well as more spawning habitat, side channels, multiple channels, deep pools, riffles, woody debris and streamside vegetation such as willows, brush and cottonwoods.

It’s an example of what Thurow calls a shifting benchmark. He authored a series of reports on the Big Wood’s fishery in the late 1980s and in 1990. Residents accept the river’s present condition as the normal, unaware of its historic highs, he noted. The Big Wood is still a good fishery; it ranked third in popularity among Idaho rivers in the most recent statewide survey of anglers in 2011, Thurow said. The Big Wood had more than 25,000 fishing trips that year.

The river’s just not as great as it once was, he said.

“The quality and the quantity of the habitat regulates the fish population,” he said. “We’ve gone from complexity to more and more simple. There’s a net loss in the numbers of trout and the size of the trout.”

But with the right actions, the river is capable of returning to something similar to its earlier form, Thurow said. He said restoring natural river function will aid downstream property owners, because the river would be able to disburse its erosive velocity easier. That would help prevent property damage, he said.

“When I was up there in the late ’80s and in the ’90s, I saw a lot of areas with great habitat, and it’s not there anymore,” he said. “That river is still capable to supply those [larger] fish. Draw a line in the sand and say, ‘We’re going to keep what’s left.’”

Streamside setbacks

Thurow delivered his last report to the Idaho Department of Fish and Game in 1990. That year marked the start of an intense, 10-month process to create Blaine County’s 75-foot streamside setback ordinance. It means landowners cannot develop within 75 feet of the high-water mark.

A committee of conservationists, riverfront property owners, county commissioners, biologists, real estate agents, land-use planners and engineers created the draft ordinance. In July 1991, the county commissioners approved it. It remains a significant legal protection of the river today. Ketchum has a 25-foot setback, while Hailey has a 100-foot setback.

Debate was hot from the start. Riverside property owners threatened a lawsuit. Forty-nine percent of wetlands in the Big Wood River drainage were in private ownership in the early 1990s, according to a 1997 study. Wetlands can include riparian areas, which are typically defined as lands near flowing water. Wetlands also include areas with less or no stream flow.

“I don’t believe any of this will stand up in court,” Nick Purdy, a riverfront property owner, told the Blaine County Planning and Zoning Commission in April 1991. “It will split the county and cause many problems for years to come.”

Others praised the proposal as a way to stem habitat loss from property development.

“Right now, the Big Wood River is turning into Sunset Boulevard in L.A.,” real estate agent Dick Dahlgren told the commissioners at that same meeting.

The ordinance represented the county’s first legislative attempt to regulate the Big Wood on a comprehensive basis, said Len Harlig, who served on the Planning and Zoning Commission at that time. He later served on the Board of County Commissioners from 1993 to 2001.

“It was controversial,” Harlig said of the ordinance. “Everybody had their underwear up into knots. That was the first really comprehensive ordinance that was put together. That was the beginning of it.”

Master plan

Thurow said the Big Wood needs more of that kind of comprehensive policy and analysis. He said assembling a master plan could be useful.

The plan would bring together the U.S. Army Corps of Engineers, the Idaho Department of Environmental Quality, the Department of Fish and Game, the county, the cities of Ketchum, Hailey and Bellevue, landowners and conservation groups such as The Nature Conservancy, Trout Unlimited and the Wood River Land Trust.

That would guide restoration efforts, identify policy changes and determine where it would be appropriate to develop near the river and where it would be inappropriate, Thurow said. The public is an essential element to that process.

“The master plan development needs to be a public process,” Thurow said. “It needs to have expertise. The public needs to be a key player. The P&Z and the county commissioners are going to respond to the public input.”

Harlig said a master plan has been discussed since 1991, but it has not been created.

In 2014, Trout Unlimited and the Land Trust created the Home Rivers Initiative. In concert with the U.S. Bureau of Land Management and the U.S. Forest Service, the groups undertook a watershed-scale assessment of the Big Wood River. The study was released in 2016.

In 2002, the Idaho Department of Environmental Quality assembled a management plan for the Big Wood River’s water quality under the federal Clean Water Act.

The plan established limits for pollutants such as phosphorus, bacteria, excessive sediment and wastewater. It also measured the appropriate temperature for sections of the Big Wood, which is classified as a cold-water stream.

DEQ conducted a five-year review of that plan and released the results in December. It found that water quality had improved in some stretches, stayed the same in others and degraded in small portions. The report recommended further monitoring.

Harlig said he sees potential for a master plan following the flooding last spring.

“We have talked about that, but it’s not an inexpensive proposition to do that,” he said. “Where we are today is different from where we were in 1991. There are so many entities that are interested and involved in the river. It’s been difficult to try and reconcile all of those interests and come to some sort of compromise.”

A success story

The extremely high value of riverfront property remains a challenge for restoring the Big Wood River. More than 300 homes sit on or near the riverbanks between North Fork and the Bullion Street bridge in Hailey, according to an Idaho Mountain Express analysis.

In other watersheds, riverfront property can be acquired and restored relatively cheaply, Thurow said. Parts of the floodplain or wetlands can be acquired and kept free of development.

“These high property values make it more challenging,” he said. “One of the things that sets the Big Wood apart is the tremendously high property values. It doesn’t mean it couldn’t happen. There could be some big donors that come in.”

Restoration of the Napa River in the San Francisco Bay Area may offer an example to follow.

The river flows 55 miles through the heart of the Napa Valley, famous for its fertile soils and climate that make it perfect for growing wine grapes.

As the wine industry in California and the U.S. boomed in the 1960s and ’70s, vineyards encroached on the river channel. Vineyard owners built higher and higher berms to protect their vines, but it led to devastating floods downstream, said Gretchen Hayes, who worked on the restoration project with a consulting firm called Tessera Sciences.

A 1986 flood in the city of Napa, which is downstream from vineyards, was so severe that it killed three people and caused more than $100 million in damage, according to the Napa Valley Register.

Hayes said the floods spurred a community process to restore natural river function and reduce flooding risks. In 1998, Napa County voters passed a half-cent sales tax increase to fund watershed improvements, which supplied $40 million over 20 years.

In the Rutherford section in the heart of the valley, where vines ran too close to the banks, vineyard owners agreed to sacrifice vineyard acreage to increase riparian habitat and restore river function. It took more than 10 years to finish the restoration work. A consultant was hired to create a conceptual design for the project.

Hayes said that land is worth $400,000 an acre. While that was an expensive proposition, landowners and vineyard managers were confronting high costs of replacing their berms, which would erode and wash out during high water and floods.

Rather than perpetuate the “berm wars,” as Hayes called it, they sought a systemic solution by restoring the riverbanks to their pre-existing state as much as possible.

“It ping-ponged the problem from one property to another,” Hayes said of the berms. “The more they confined the river, the more erosive it became.”

Vineyard owners next to the river agreed to assess themselves to pay for ongoing maintenance for the improvements for 20 years. That helped attract state and federal grant funding, Hayes said.

Most importantly, the process was guided by landowners working collaboratively with the local, state and federal government, said Michael Honig, a riverside vineyard owner and board member for the Napa Valley Vintners.

“We gave up some of our most valuable land,” Honig said. “Over time, it will be a pretty big economic impact. You give something up individually but you gain something collectively. Instead of government coming in and saying, ‘You have to do this,’ it was your neighbor. It really wasn’t our land anyway. That land used to be floodplain.”

Overall, it cost $30 million to restore five miles in the Rutherford Reach section, Hayes said. It has also inspired riverfront landowners in other portions of the valley to try and emulate that success, she said.

The restoration work has been critical because endangered salmon and steelhead run and spawn in the Napa River, which is a rarity for rivers in Northern California. For the first time in 40 years, beaver dams have been spotted along the river, Hayes said.

A survey counted six structures in 2014. Beavers are extremely effective, natural stream engineers, Hayes said. Their dams will wash out in high flows, but pool cold water in the summer to aid fish.

“What had been your traditional trout stream with pools, riffles and glides had become a trench,” Hayes said of the Napa River prior to restoration. “The beavers came back. Beavers hadn’t been seen on the river in decades.”

Looking at the Big Wood River, it’s obvious that vineyards are easier to move than homes, and the costs are high for restoration work. But Harlig said he’s optimistic the issue can be addressed.

“I think there’s a real financial burden here and probably beyond the county’s ability to handle on its own,” he said. “It’s important that we allow the floodplain to do what it’s supposed to do. We have allowed too many homes to get too close. That floodplain has suffered. It’s a big issue and it’s going to have to be dealt with. Kicking it down to the next year’s flood has not been an effective technique.”