Catch it, Keep it, Use it!

Cistern Installation and Care

From watering gardens, washing your car or flushing toilets, cisterns are a great way to harvest rain water for domestic and agricultural use. Limiting stormwater runoff can positively impact local ecosystems as well as your bank account; saving money and saving the environment.

Mike Dupree (USS Founder) walks through all the parts and pieces that make a cistern work, and shows the methods for maintaining your cistern. —>

Does Size Matter?

Cisterns come in a variety of shapes and sizes. Typically, one 500-gallon cistern is best for a single downspout connection. It all depends on how much water you want to capture from roof runoff. The general rule of thumb is 1 square foot of roof area = 1 gallon of water. So, a 500-gallon cistern is capturing 500 square feet of roof runoff. 

So size is important because an undersized cistern will overflow easier and cause water to pool around the foundation or increase erosion.

Top: 500 gallon;
Bottom left: 1500 gallon;
Bottom right: 305 gallon

Parts of a Cistern

  1. Leaf Filter: Used to capture leaves/debris that may otherwise clog the tank or piping. Some tanks can have a manhole filter that fits in the top of the tank or a filter connected to the downspout.

  2. Overflow Pipe: This piece helps in the rare case where a cistern is in danger of overflowing during a heavy storm event. Before the cistern has a chance to overtop, the overflow device, located just under the top of the cistern, releases excess water from a pipe that is directed away from the foundation of the home.

  3. Passive Drawdown: This device allows water to flow from the bottom of the tank using only the internal water pressure. Connecting drip irrigation will allow water to gradually drain across a raised flower bed or garden.

  4. Internal Pump: This device works in tandem with a control switch and timer to pump out water to a hose bib or other connection for irrigation your garden.

  5. Hose Bib to Pump: A simple connection to your garden watering system.

  6. Wifi Controller/Pump Start Relay: In order to use an internal pump, a control switch and irrigation timer/control box is installed near an exterior electrical outlet. Using the Rain Bird WiFi Module and phone app allows the irrigation control box to send a signal to the pump switch to turn on the pump.

  7. Wifi Tank Gauge: Allows you to remotely monitor the amount of water in the tank for irrigation use.

Maintenance & Winterization Checklist

  • In the Winter when harvesting water is no longer needed, unplug the pump start switch and irrigation control box from the exterior outlet or other power source. Then gently wrap any cordage around the box to keep it away from the ground.

  • Make sure to periodically clean the leaf filter between rain events to avoid buildups of debris. The same goes for cleaning your gutters if there is no leaf filter installed.

  • On occasion, water that has sat unused in a cistern (especially in the summer) can get an odor. Fixing this is easy. Using a little bleach can clear up the smell in no time, and it won’t hurt your garden. Wellcare has a useful guide to cleaning and sanitizing a cistern here!

  • When winterizing your cistern, the main concern is not leaving water in the tank to freeze. The easiest solution is to turn on the passive drawdown device to allow any water that is captured to drain gradually over the garden or away from the foundation of your home.

If you are interested in installing a cistern on your property or know of a site that would benefit from a cistern installation please fill out the this form!