Youths in Glasgow's east end have been caught on CCTV
Evidence from CCTV footage is to be used to identify people who vandalise fire hydrants across Glasgow.
The "zero tolerance" campaign, from the fire service and police, coincides with the start of the summer school holidays - the peak time for hydrant vandalism.
Both have warned that young people risk serious injury while opening and damaging hydrants.
Fire crews were called to 344 open hydrants in May, compared with 1,404 for the whole of 2007.
Strathclyde Fire and Rescue Service assistant chief officer Neil Turnbull said: "Firefighters need water to fight fires but our task becomes very difficult if water pressure is reduced or if hydrants are impossible to open because they have been damaged.
"Parents should warn their children about the dangers of hydrant vandalism and I would ask responsible adults to prevent children misusing hydrants and report anyone involved to Strathclyde Police.
"Hydrant vandalism is an unacceptable form of anti-social behaviour that will result in prosecution."
The new initiative follows a successful pilot scheme in Glasgow's east end.
Video footage showed one incident where young men were almost hit by a door and window they had placed over the water jet.
Another clip showed a young girl almost being hit by a car whose driver had not seen her playing in the spray from an open hydrant.
Ch Insp Brian Connel, of Strathclyde Police, said: "During a hot summer's day playing under a fountain of cold water may seem like fun but it can have serious, even fatal, consequences.
"Water hydrant vandalism increases in the warmer months and those who interfere with these vital water supplies often don't stop to think of the waste, the cost and even the possible risk to life."