Overview of Raintanks

What is a Raintank?

Rainwater tanks capture runoff from rooftops, storing water for use during dry periods, like summer. They come in various materials, including polyethylene. Our examples focus on polyethylene tanks due to their affordability, lightweight nature, and ease of installation. 

In Santa Cruz County, rainwater is non-potable and must be labeled as such. While it can be treated for drinking, this guide focuses on its use for irrigation. When watering food crops, avoid direct contact with the produce. For general landscape irrigation, basic filtration, like leaf catchers and a first flush leg is usually sufficient. Visit our Growing Food page for more details. 

What to consider when deciding to install a Raintank?

• Size: For home installations, tanks between 200 and 600 gallons are typically ideal.

• Location: Place the tank near a downspout and close to where the water will be used.

• Elevation: Choose a higher location to allow gravity to aid in draining the water.

• Overflow: Decide where the overflow will go—either back into the drain pipe or into a bio-swale to store additional water underground.

• Local Codes: Regulations for rainwater harvesting vary by city/county. In Santa Cruz no permit is required if the Rainwater Harvesting Tank System is less than 5000 gallons, the height to width ratio does not exceed 2, and no electricity is used.

• Seismic bracing: Tanks with height less than a 2:1 ratio do not present seismic risks and do not require seismic bracing.

Navigate to our Resources page for further reading and to our Installation page for more details on installing your tank.