Riot founts were used to soak and disperse a mob in the third century of the Human Era in the Tortallan Universe. They have been known to be used in different countries, including Galla and Tusaine, in combination with freezing spells. At least six riot founts were installed under the Nightmarket in Corus and were activated during the Bread Riot. Beka also wanted to know why they were not put in use at a large riot a few months before. They didn't really work in the Bread Riot, however.
The riot founts have only been mentioned during the Bread Riot in Bloodhound.