Colored dyes used in canals for water flow monitoring

Periodically throughout the irrigation season, Modesto Irrigation District (MID) applies Rhodamine WT and Uranine Liquid, harmless dyes, to our canals to aid with water flow monitoring. As a result of the dye application, the water in the canals could be red, green, yellow, or blue in color. Some foam may appear in the water too following dye applications.

The dyes are harmless to humans, animals, and vegetation and are soluble in water.

Rhodamine WT and Uranine Liquid are often used as water tracers to determine the rate and direction of water flow. Other irrigation districts also use these dyes to aid in their water flow monitoring activities.

During irrigation season (typically March through October), MID also reminds our community of four canal safety rules – stay away from canals, learn to swim, swim and play in safe places, and always swim with an adult.

Media Contact

Melissa Williams | Email Melissa Williams | (209) 526-7390

About the Modesto Irrigation District (MID)

The Modesto Irrigation District, established in 1887, is a vertically integrated public utility located in California’s Central Valley. MID provides irrigation water to more than 2,300 agricultural accounts irrigating close to 60,000 acres and electricity to more than 131,000 residential, commercial, and agricultural accounts in Modesto, Empire, Salida, Waterford, and Mountain House as well as parts of Escalon, Oakdale, Ripon, and Riverbank. MID also treats, delivers, and wholesales up to approximately 67,000 acre-feet of drinking water per year to the City of Modesto. For more information about MID visit MID's website or follow MID's Facebook Page and MID's X (Twitter).