In preparation for the colder weather, we recently winterized the cistern at Discovery Point. The cistern collects runoff from about 1/3 of the roof and fills up in a 1″ rain event. It can hold 1,050 gallons of water. In order to prevent ice buildup and damage to the cistern in the winter months, we disconnect the cistern from receiving water from the gutter system. There is also a pipe designed to collect leaves and other debris from the roof (keeping them out of the cistern) that has to be opened.
If you have a cistern, or even a rain barrel, you should winterize it before freezing temperatures hit. Drain it completely, then prevent any new water from getting inside it.
Want to learn more about rain barrels? Check out these links!