I was called to a job the other day where water was leaking down off the roof of the house. The lady was loosing many gallons of water a day and she wasn't sure where the leak was coming from.
Come to find out that the water was leaking out of the swamp cooler on the roof. I removed the swamp cooler side panels and found that the problem was the float valve. It was not working properly so the swamp cooler was overfilling the water tray and leaking out of the side.
I replaced the float valve with a new one and adjusted the water level so the swamp cooler would not overfill. This is an easy project that can easily save on water usage if the swamp cooler is leaking.