Its way too common!!  But there is a very cost effective product that will prevent that from ever happening again. The Melnor Automatic Water Timer goes between your water faucet and your garden hose. Or it can be installed anywhere in your incoming hard plumbed water supply. It will meter any amount of incoming water between 100 to 1600 gallons. Simply set the desired amount of water needed and this unit will automatically shut off the water supply when the amount set is reached. It even has a "continuous flo" setting for times when you want to water the yard.

No pond should be without this "life-saving" product.