ELLENSBURG — An herbicide treatment for Eurasian water milfoil in Kittitas County’s South Fio Rito Lake will close the lake to swimming July 6 and 7.
The 25-acre lake in Ellensburg will be treated July 6 with 2-4-D herbicide, under a permit approved by the Washington Department of Ecology, said Washington Department of Fish and Wildlife (WDFW) noxious weed coordinator David Heimer.
Signs will be posted at the lake advising swimmers to stay out of the water July 6 and 7. The lake will reopen for swimming July 8. Fishing in the lake will not be affected, Heimer said.
WDFW will also treat the shoreline of Lavender Lake, Mattoon Lake and the shorelines of North and South Fio Rito lakes July 6-9 with imazapyr herbicide to control yellow flag iris. No lake-use restrictions are necessary for that work, Heimer said.
North Fio Rito Lake and Mattoon Lake were treated in 2008 and 2009, respectively. A subsequent survey showed excellent control of milfoil in these lakes, Heimer said. He will snorkel with an underwater camera to check for any missed milfoil later this summer. If any re-treatment is needed, public notice will be given in advance.
Yellow flag iris and Eurasian water milfoil are both invasive, non-native plants that choke out native habitat for fish and wildlife if allowed to spread, Heimer said.
The weed-control work is a cooperative project of WDFW, the Kittitas Noxious Weed Control Board, state departments of Agriculture and Ecology, and the Kittitas Field and Stream Club.