Water Barrels collect storm water from your roof. The water can be reused for your plants in your yard as well as in your home. This saves money on your water bill, as well as resources storm water in a sustainable way. Use the water barrel instead of a hose. A hose has a typical water flow rate of 9 to 17 gallons of water per minute. Using a typical sprinkler for your plants results in water usage of 12-30 gallons per minute.