Taking your Tri-Cities dog to the Columbia River? Beware of summer herbicide applications

The U.S. Army Corp of Engineers will be treating some parts of the Columbia River at the Tri-Cities with a herbicide from July 15-19 and again as needed at times through Sept. 1.

Fishing and swimming will not be restricted by the Corps.

But it says that pets and other animals should not drink the treated water for 24 hours after the herbicide is applied.

There also will be a three-day restriction for using the water in treated areas for drinking and watering lawns, plus a five-day restriction for watering crops.

Diquat dibromide will be used to control flowering rush, an invasive aquatic plant species that can have dense growth along shoreland, at an application rate of two gallons per acre of surface water.

It will be used on 1.65 acres near Osprey Point in Pasco, on about 2.25 acres between the blue and cable bridges, and on 4.25 acres just above the mouth of the Yakima River.

The Corps will post notices on the shorelines of areas being treated 48 hours in advance.

The Washington State Department of Agriculture says Benton County is one of three counties in Washington with the most flowering rush, sometimes called “water gladiolus.”

It is perennial that has a flower stalk up to five feet tall with light pink flowers and thin, upright leaves.

It roots in mud and shallow water along the shorelines of lakes and slow-moving rivers, according to the Washington state Noxious Weed Control Board.

This story was originally published June 26, 2024 at 1:39 PM.