A healthy Great Salt Lake could be bad news for mosquitoes, expert says

Editor’s note: This article is published through the Great Salt Lake Collaborative, a solutions journalism initiative that partners news, education and media organizations to help inform people about the plight of the Great Salt Lake — and what can be done to make a difference before it is too late.

DAVIS COUNTY, Utah — More water is normally good news for mosquitoes, but if it’s in the Great Salt Lake, it’s the exact opposite. That’s according to Gary Hatch, the Manager of the Davis Mosquito Abatement District.

“The Great Salt Lake is so salty… as it comes up into the marsh it kills the vegetation and reduces the mosquito habitat,” Hatch said.

Hatch said the marshlands along the lake in Davis County have only expanded as the lake’s levels have declined over the years. And not only is the marshland a prime breeding ground for mosquitoes, Hatch said it affects how much water reaches the Great Salt Lake.

“Much of the water flowing from out from our foothills…doesn’t even make it to the lake because it gets absorbed by the marsh,” Hatch said.

Most of the runoff in Davis County flows towards the struggling Farmington Bay, which has been pinpointed as a hotspot for exposed lakebeds, and subsequently, a source of toxic dust flying around when the wind blows. A chunk of the water flowing through Farmington Bay comes from the Jordan River, which runs north from Utah Lake.

Davis County saw a slew of mosquitoes this spring. Hatch told KSL TV in May, they had to treat more than three times the ground they normally do because of the record runoff.

Officials also recently detected West Nile Virus in a Syracuse mosquito pool, though it’s fairly typical to detect the virus in Davis County.

The state of the Great Salt Lake

The Great Salt Lake rose 5.5 feet since it hit an all-time record low in November 2022.

A spokesperson for the Utah Department of Natural Resources told KSL NewsRadio the lake has since dropped about 6 inches after peaking in mid-June.

Great Salt Lake Commissioner Brian Steed previously said it’s normal for the lake to gain about two feet in the winter, then drop about 2 feet in the summer.

As it stands now, the Great Salt Lake is still net positive 5 feet since hitting that record low last fall, but we’ll have to see what happens during the heat that typically comes in August and early September.

Before the 6-inch drop, Steed said the lake still needed another 5 feet to reach what scientists consider healthy levels. Hatch is hoping for that increase as well, and for the salty waters to knock back some of that mosquito breeding ground.

“It would be nice,” Hatch said with a smile.