Choosing a Rain Catchment System

Kurt Miller, Katrina Edenfeld

Anything you can do to make your environmental footprint a little smaller on this earth is always exciting. Many countries lack a consistent source of water or have a reliable source of water that is too expensive to utilize. So far in Minnesota, many of us have been fortunate enough to have a consistently clean, dependable, and safe source of potable water coming right from the tap. This type of system is by no means the standard in many countries, developed or undeveloped.

One of the many things you can do to decrease your water consumption is to install a rain catchment system to capture rain water from your roof and store it for later use.

NOTE: Do not use this water for drinking, cooking, or washing dishes. However, you can use it for almost anything else. The goal is to use the captured water for anything that does not require potable water or that clean, dependable, and safe water that comes from your tap.

Uses for catchment water include :

  • Watering your flower garden, landscape trees (not recommended for vegetable gardens), or houseplants
  • Washing your car, driveway, sidewalk, or deck
  • Flushing your toilet

Considerations in planning your rain catchment system

  • Permits or permission as needed (from your landlord, local government, or neighbors)
  • Infrastructure like gutters and downspouts are necessary
  • Size of water-containment vessel
  • Space available for the vessel
  • Quantity of ‘roof-real estate’
  • Quantity of captured water that can be used

Mandatory features for any water catchment system

  • Screen to prevent mosquitoes from entering and laying eggs
  • Secure placement to keep children, pets, and wildlife out of it
  • Overflow relief: a long, flexible tube directed away from the house

It is important to direct the overflow in a controlled manner rather than allow it to go where you do not want excess water (for instance, next to the foundation of your house). An excellent place for this overflow is a rain garden. A rain garden not only prevents rainwater from entering the storm sewer system, but it lets the ground absorb the water to recharge the aquifer. If you do not have a rain garden, direct the overflow down a slope, away from your house (and your neighbor’s). If desired, the overflow from one barrel can feed a second barrel and so on.

Maintenance Requirements

All rain barrels must be drained and disconnected from downspouts before winter. Recall that water expands on freezing. A rain barrel left in place will turn into a solid block of ice and that expanding water can damage it permanently. It may be easiest to store it inside a shed or garage if possible, especially if your system is made of wood, as snow sitting on top of the barrel will cause it to rot quite quickly. Rain barrels can also be turned upside down and left outside for the winter.

During the “rain catchment season” you should periodically check the gutters, downspouts, spigot, and overflow assembly to ensure there is nothing blocking the flow of water into or out of the vessel. When you check those things, verify that the vessel is still sturdy and not susceptible to tipping. At the same time, check for mosquitoes and small animals that may have found their way into the vessel.

Visit the Do It Green! Resource Center for a brochure on a wide selection of available catchment systems.

Read Up
  • Design for Water: Rainwater Harvesting, Stormwater Catchment, and Alternate Water Reuse, Heather Kinkade-Levario, New Society Publishers, 2007.
  • Water Storage: Tanks, Cisterns, Aquifers, and Ponds for Domestic Supply, Fire and Emergency, Art Ludwig, Oasis Design, 2005.
Act Locally
  • Recycling Association of Minnesota
    Wayzata, MN
  • Barrel Depot — Rain barrels and other supplies
    Minneapolis, MN
Rain Catchment Systems

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