A sprinkler system is one way to keep a lawn or special plants watered during the summer months. Some sprinklers are a temporary framework or just a water hose with a sprayer at the end, but a sprinkler system more commonly refers to a built in, permanent system, often with underground pipes or water feeds, sometimes with separate water sources or metering. Most sprinkler systems have timers that regulate when and how long to water the lawn. Some also have moisture sensors so that the systems will not water the yard during or right after there is enough naturally provided water through rain.