Warm weather is causing the Kennewick Irrigation District to experience large algae blooms throughout the canal system. The District receives water from the Yakima River and many of the irrigation districts throughout the Yakima Project have been experiencing this same problem. The KID’s canal system, with shallow flowing water in an open air canal more than 60 miles long in over 90 degree weather, is, unfortunately, perfect for growing algae and pond weed.

The District’s permit with the Department of Ecology dictates the types and quantities of herbicides/chemicals which can be used to fight algae bloom. There are very specific restrictions on the level of herbicide which can be used if there is run off back to a wasteway or river. These limitations protect the environment but prevent the District from treating canals to a level that completely kills the algae.

The District has been treating all our canals on a weekly rotation with an herbicide called Copper Sulfate. This appears to be helping, but will not eliminate algae completely.

Cleaning your filters and irrigation systems on a regular basis is a necessity to keep the water moving and help mitigate the effects of the algae bloom and die off. The District is doing its part by increasing staffing levels to keep KID’s filters and screens clean. Our staff will continue to look into new and more innovative ways to deal with weed control for the future.
If you have any questions, please contact Beth Smith at 509-586-9111.