How 1983′s floods damaged the Great Salt Lake

The flooding gave an invasive plant a blank slate to expand, choking out other plant life and spreading across thousands of acres.

(Francisco Kjolseth | The Salt Lake Tribune) Thickets of invasive phragmites choke an area of wetlands near Farmington Bay, pictured in November 2022. Phragmites can dam up water discharge and block the movement of most wildlife.

The floods of 1983 left lasting memories throughout Utah — thousands of sandbags lining State Street, rushing flood waters and a handful of people kayaking in the raging waters.

But the ‘83 floods continue to create lasting damage on the state’s most recognizable landmarks. The flood waters enabled phragmites, a hearty, invasive species, to take over shorelines of the Great Salt Lake, and the plant continues to wreak havoc on the remaining lake to this day.

Phragmites australis — a tall, grass-like plant that’s also known as the common reed — filled a void in the shorelines to expand across the eastern shores of the Great Salt Lake. The thick, tall phragmites tend to shade out native plant species, killing off other plant life.

[Related: In 1983, downtown Salt Lake turned into a river. With Utah’s deep snowpack, could flooding be next?]

Phragmites covered around 23,000 acres by 2012, and, despite mitigation programs, are still sucking water out of the lake’s wetlands.

“When the floods happened, and the lake filled up, and that shoreline came up,” Keith Hambrecht, an invasive species coordinator with the Utah Division of Forestry, Fire and State Lands told The Salt Lake Tribune. “It stayed up long enough to kill off most of the vegetation.”

(Francisco Kjolseth | The Salt Lake Tribune) Hydrologists place groundwater monitoring devices near an amphibious vehicle used to navigate the Wetlands of Farmington bay that has also been used to widen and maintain a channel for treated discharge from the central Davis sewer treatment plant, pictured Thursday, Nov. 2, 2022. Thickets of invasive phragmites choke the area, that can damn up the discharge and block the movement of most wildlife.

Karin Kettenring, a professor of wetland ecology at Utah State University’s Department of Watershed Sciences and Ecology Center, explained the blank slate of wetland left by the flood allowed the hearty plant to spread unchecked.

“That was the perfect opportunity for phragmites to take hold,” Kettenring said.

Phragmites are destructive because of how much bigger they are than other plants around them. It can grow to be 10 to 15 feet tall. Because it’s bigger, it also soaks up more water than native plant life, an especially big problem for the drying lake.

Kettenring said phragmites also change the habitat of migratory birds, as the invasive plant doesn’t provide the seed and other animal life that migratory birds thrive on.

“You basically end up losing that valuable habitat,” Kettenring said.

After the floods, the plant took hold in thousands of acres around the Great Salt Lake through the 1980s and 1990s before conservationists began fighting back. Kettenring said the only reason phragmites haven’t taken over all of the lake’s wetlands is because of aggressive land management.

It takes around three to five years to remove phragmites, but the plant’s prevalence has been greatly reduced in focused areas. For example, a plot of over 10,000 acres in Farmington Bay has seen a 65% reduction in phragmites in recent years, Hambrecht said.

In the past seven years, which is how long Hambrecht has been focusing on phragmites, he’s seen wetland habitats restored to their native state, which includes migratory birds coming back to revitalized areas.

It’s tough work, but the growing community of people focused on controlling phragmites shows it can be done.

“There’s a pretty deep understanding of how to do it well,” Hambrecht said. “We just have to keep at it.”

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