Why the Great Salt Lake wetlands are key to preventing spring flooding

Utah’s wetlands are vital during times of drought and flooding, but they haven’t always received the appreciation and attention they deserve.

At the Ogden Bay Waterfowl Management Area on the shores of the Great Salt Lake, manager Rich Hansen is busy preparing for snowmelt. He clears logs and debris from the intakes. It floods the parking lots that duck hunters usually use in the fall. Its water control structures are wide open, allowing all of the Weber River’s runoff to disperse across the bay’s 19,000 acres of wetlands instead of ending up in people’s basements.

“These wetlands are so, so crucial in dampening flood waters and distributing the water once it comes out here,” Hansen said, while a chorus of songbirds and shorebirds chirped nearby.

He is happy about the rise. This time last year, after a nearly bone-dry winter, the Weber River was trickling at just 60 cubic feet per second, Hansen said. However, after this season’s record-breaking snow cover, it’s currently gushing at 3,870 cubic feet per second. This is almost four times the average flow.

After slowing and seeping through the wetlands of Ogden Bay, it ripples to the Great Salt Lake. A huge area that was dry just a few months ago now has water again. It’s only a few inches deep, but it keeps out a source of noxious dust for those on the Wasatch front.

And it attracts millions of shorebirds, ducks and other waterfowl on their spring migration.

“We know that just saving the Great Salt Flats isn’t enough,” said Coryna Hebert, a biologist for Utah-based Ducks Unlimited. “It simply averted an ecological catastrophe that we were facing [at] at the same time last year.”

The Great Salt Lake has dropped to record lows for the past two straight years, reaching an all-time low of 4,188.5 feet above sea level in November. Its salt flies have been all but eradicated. Salt concentrations were so high that even the lake’s brine shrimp were on the verge of collapse. Both creatures are cornerstones of the food web on which millions of migratory birds depend each year.

However, after a record-breaking winter, the lake’s elevation is more than 3.5 feet from its record low.

“It buys us a little more time,” Hebert said, “to implement some of these actions, we need to start conserving water and reversing the slow trend of the lake’s annual decline.”

An important part of restoring the lake’s health and resilience is restoring its wetlands. Wetlands provide diverse habitats for wildlife and improve the lake’s water quality while helping to replenish groundwater and mitigate flood damage to nearby communities.

But Ogden Bay was perilously close to losing its wetlands to this spring’s runoff.

A 3-mile levee built in 1937 to create the administrative area has long been neglected and left to decay. The earth structure was originally 21 feet wide, but sections are currently as narrow as 7 feet.

“With the currents we are experiencing, the levee would be washed out and managers would lose all control of the water to Ogden Bay,” Hansen said. “We would let thousands of acres dry up later in the summer.”

Ducks Unlimited is using part of a $1 million federal grant from the North American Wetlands Conservation Act to help restore Ogden Bay’s dam by bringing in boulders to support the structure and putting it back in its place restore original condition.

The wetlands of the Great Salt Lake are controlled by dikes and levees

The Great Salt Lake is home to about a third of Utah’s vegetated wetlands, according to the Utah Geological Survey. Many of these ecological spaces are heavily engineered and carefully managed. In the 1930s, the Civilian Conservation Corps built levees and levees at Ogden Bay, Bear River Bay, and Farmington Bay to prevent mass bird deaths caused by avian botulism.

The toxin comes from bacteria that thrive in the stagnant water that remains after the lake rises in spring and recedes in summer, leaving warm, stagnant pools. Bugs consume and concentrate the bacteria. Birds eat the bugs and become infected. The disease slowly paralyzes her and causes her to drown.

“These levees allow managers to manage and manipulate the water,” Hansen said, “and keep it… constantly moving.”

Artificial wetlands have also helped biologists gain control of phragmites, an invasive, water-sucking reed that first appeared in the Great Salt Lake wetlands after the 1980s floods. Since then it has ravaged the landscape, wiping out native species and wildlife habitats.

“Successful management of phragmites,” Hebert said, “like removing a large stand, often takes three to five years with many different treatments of herbicides that graze, cut, mow, and sometimes burn.” I mean it’s really hard to get rid of it.”

In controlled wetlands like Ogden Bay, managers can drain specific areas to spray the weeds or cage cows to eat. Or they can open the floodgates and try to smother the plants.

“We probably developed 12,000 acres that were phragmites 10 years ago,” Hansen said. “That’s why we don’t want to lose the progress we’ve made.”

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And with climate change, drought, and a growing population in the West, wetlands are rapidly being lost to drought and development. That makes the Great Salt Lake wetlands crucial for supporting birds and preventing endangered species from being listed.

“The best wetlands that we have in the West are these managed wetlands,” said Ryan Sabalow, a spokesman for Ducks Unlimited. “Because we have so few of them, you have to make sure they run perfectly.”

Are Wetlands Disappearing Across Utah?

Utah’s resource managers don’t have good data on how much of the state’s wetlands have been lost in recent decades. Although they provide an extremely productive habitat, prevent flooding, and keep the environment healthy, humans have long viewed them as swampy, troublesome nuisances.

“In general, as a society, we’ve viewed wetlands throughout North America as badlands,” said Karin Kettenring, a professor of wetland ecology at Utah State University. “So there was always this urge to fill in and drain wetlands.”

In just 14 years since Kettenring relocated to Utah, she said she’s watched development encroach along the periphery of the Great Salt Lake into zones that would have helped absorb the rapid drain that might be coming this spring. She has also seen development emerge along the historic floodplain of the Logan River, a tributary of the Great Salt Lake basin.

“It’s both at the end of the line at the Great Salt Lake,” Kettenring said, “but also in the recognition that wetlands are important upstream in slowing flow throughout the watershed.”

Utahns and other western communities have manipulated rivers and waterways for flood control with dams, dikes, and reservoirs for more than a century. But as the Great Salt Lake floods of the 1980s, the Weber County floods of 2011, or the Logan and Box Elder County floods of 2017 show, these solutions don’t always work.

“Some would like to have complete control,” Kettenring said, “and develop the system completely hard, which tends to be a much more expensive and not necessarily a better approach.”

All the damage to homes and infrastructure left by the recent floods doesn’t come cheap, either.

Still, Kettenring said, she sees value in the engineering being done in the wetlands of the Great Salt Lake, particularly with all of the dams, diversions, farms and developments in the lake’s watershed.

“Without fundamentally changing the way we use our water upstream,” Kettenering said, “it’s a logical answer. I see no way we could have wetlands without them at this point.”

And the professor is confident that the lake will see a similar enthusiasm for wetland conservation because of the attention, concern and investment it has received from policymakers and lawmakers.

“I have a certain optimism,” said Kettenring. “Awareness of the role of the Great Salt Lake has grown a lot. For me, that includes the wetlands. You can’t really separate the lake from the wetlands.”