Wary, concerned Riverbank residents flooded city hall telephones reporting and seeking information recently about the strange red color of the water in the canals flowing past the south side of town.

Alarm spread through the area, with reports even airing on Sacramento television stations about the incident.

City Public Works officials took to social media pages to calm residents and explain “the ‘red ooze’ in the irrigation canals,” pointing out that it was red dye used to track the application of herbicide through the canal system.

“The herbicide is used to combat the aquatic weeds (aka water lilies) you sometimes see floating in the canals. These weeds do a great job of jamming up the pumps and ladders that move the water through the canals,” officials posted.

And they reassured residents, “There is nothing to worry about – for one, this water is not the water coming into your home, this is for irrigation purposes only; and two, the herbicide and dye are not harmful to humans, fish, or animals.”

They said that the Modesto Irrigation District (MID) typically runs herbicide through the canals at least twice a season; the difference this year is that MID has decided to track the herbicide by adding the red dye.

“Expect to see the canals turn red again toward the end of May or early June,” the spokesperson said.

By Wednesday last week, the dye had dispersed and the only red to be seen on the canal water was the fiery sunset reflected that evening.

Officials referred residents with continued concerns, either about the red dye or the irrigation process, to the irrigation district, because the canals and the water system are not operated by the city, but are owned by MID. They suggest citizens might call them at 209-526-7337, or 1-800-335-1643.