A project to improve Kennewick's water supply had the unintended consequence of damaging the area behind Zintel Canyon Dam.
A gully 50 feet wide and 24 feet deep in places opened up in the canyon and adjacent irrigation ditch while the city was testing for a $4 million project to store water in an existing aquifer in the Southridge area, said Evelyn Lusignan, the city's customer service manager.