High runoff is both good and bad news for algal blooms on Utah Lake
Jun 1, 2023, 6:50 PM | Updated: 8:45 pm
PROVO, Utah – Utah’s record-breaking snowpack and resulting runoff bring both good news and bad news for the development of harmful algal blooms on Utah Lake this year.
“What we worry about with these blooms is there could be toxin exposure and health consequences for people who get some of that algae into their body,” Hannah Bonner, an environmental scientist with the Utah Division of Water Quality said.
Bonner said algal blooms form when there are warm, sunny days, warm water temperatures and nutrient pollution—like fertilizer.
Fortunately, the high runoff flowing into Utah Lake should help keep the lake’s water temperatures lower for longer.
“High runoff has multiple benefits,” Bonner said. “Of course, bringing down water temperature, keeping the water cooler inhibits algal growth and then also just movement, turbidity.”
Utah Lake is susceptible to algal blooms because it’s shallow, warms up quickly and gets extra nutrient pollution from nearby urban areas, Bonner explained. And this year the lake is getting an extra dose of nutrients that could fuel algae growth later this summer.
“We also have had a lot of flooding, a lot of runoff, some big rain events, eroding river and streams, which is actually going to introduce more nutrient pollution into our waterbodies so more food for algal growth,” Bonner said. “So once our water temperatures get warm, and if we have a really hot, sunny summer that could result in larger bloom events happening later this year.”
In recent years, algal blooms started to develop on Utah Lake around mid-June. This year, Bonner said the blooms could be delayed if the water level stays high and cold. The same scenario could play out in other waterbodies across Utah.
“We’re hopeful that these deeper, colder, reservoir temperatures will at least delay the onset of harmful algal blooms around the state,” she said.
Utahns can help prevent algal blooms by not over fertilizing their yards and keeping yard waste and pet waste out of gutters and storm drains.