How to Install a Rain Catch Cistern

Draw plans of the perimeter of the home or building. The plan must include measurements and detail the footprint of the home and should include shady locations for each cistern alongside the house. If the water is intended for an outdoor use such as a garden, plan the location on the side of the house with the garden to make accessing the water easier. Include the elevations of each side of the home that will have the cistern and any additional sides where drain pipes will be located that connect one or more gutters to the cistern.

Purchase a complete cistern package or create your own cistern. Do-it-yourself cisterns should be made from new or used food grade storage tanks. Used tanks should have only been used for food or water and never have held chemical agents. Make modifications by adding an inlet, an outlet valve, an overflow hose, a screened air vent and painting non-opaque tanks to shade stored water from algae growth. Purchase or make a stand or pour a concrete pad for very large tanks, the first-flush diverter and roof washer. If desired, purchase a pump system to pull water from the tank and filtering system to ensure it is safe for human consumption.

Install gutters along the roof of the home in a normal method recommended by the manufacturer with leaf screens and downspout end caps. If the home already has gutters, clean thoroughly to remove debris and install leaf screens.

Set the cistern in place. Make sure the stand is level and on hard ground. Once filled, the weight of the water may cause the stand to shift. Ideally the stand should be set on a concrete pad or footings.

Connect the roof washer to the inlet of the cistern according to manufacturer directions or using standard PVC pipe connection methods for the homemade units.

Connect the first-flush diverter to the roof washer according to manufacturer directions or using standard PVC pipe connection methods.

Attach PVC pipe from the first-flush diverter to one or more gutter downspouts. Most often this cannot be accomplished with a single length of pipe even if working with only one downspout, but will require a combination of pipe length and joints.

Ensure the overflow hose is set to drain away from the house. Ensure the vent screen is secure to prevent insects from entering the cistern.

Install optional items such as the pump and filter system.