Rain Barrel and Water Collection Tanks

Rain barrels for gutters are the simplest way to put your roof to work. A rain barrel sits at the bottom of a downspout and fills every time it rains, and a spigot or hose connection lets you use that water on beds, gardens and potted plants instead of paying for it. A larger water collection tank, sometimes called a gutter tank, does the same job at a bigger scale and can be fed by several downspouts at once.

Gutters Made Easy installs rain barrels and water collection tanks and ties them into your gutters and downspouts, so the water actually reaches the barrel, the overflow goes somewhere safe, and the system keeps working through a Hill Country storm. Plants do well on rainwater because it is free of the chlorine and minerals in tap water, and every gallon you catch is a gallon of runoff that is not carrying yard chemicals into the storm drain.

More than most people expect. The Texas Water Development Board’s Texas Manual on Rainwater Harvesting puts it at approximately 0.62 gallons per square foot of roof for every inch of rainfall. A 1,000 square foot section of roof draining to one downspout can collect about 620 gallons from a single inch of rain. That would fill a typical 55-gallon rain barrel eleven times over, which is why a lot of owners start with a barrel and end up adding a tank.

Size your storage to the roof feeding it and to how you plan to use the water. A barrel or two works for a patio garden. Beds, a vegetable garden or a small orchard usually call for a tank.

• Diverters. Sized to the downspout, they fill the barrel and send the rest down the downspout once it is full.
• Screens and first flush. A leaf screen at the inlet and, on tanks, a first flush diverter that dumps the dirtiest first gallons off the roof before water reaches storage.
• Overflow. Every barrel and tank needs a place to send extra water away from the slab. Some owners tie the overflow into buried drain lines so it leaves the yard instead of pooling.
• Clean gutters. Rainwater collection works best with gutters that are sized for the roof and kept clear, so debris does not end up in the barrel.

If your gutters are undersized, leaking or missing on the side of the house where the barrel should go, we can install new seamless gutters at the same time so the whole system is built to feed the barrel or tank.

Collecting rainwater is legal in Texas, and the state encourages it. According to the Texas Water Development Board, Texas Tax Code 151.355 allows a state sales tax exemption on rainwater harvesting equipment, and Texas Property Code 202.007 prevents homeowners associations from banning rainwater harvesting installations. Your HOA can still have rules about how a system looks or where it sits, so check your guidelines before you buy.

If you are an Austin Water customer, the city offers a rainwater harvesting rebate of up to $5,000 based on storage capacity for a rain barrel or cistern system. Rebate terms change, so confirm the current requirements with Austin Water before you install. Our page on gutter work for Austin homes covers how we lay out the downspouts when a tank is part of the plan.

Does a rain barrel need to be under a gutter? It needs a steady source of roof water, which almost always means a downspout. On a porch or entry without a downspout, a chain hung from the gutter outlet can guide water down into a barrel instead.

How long can water sit in a rain barrel? Use it within a couple of weeks when you can, keep the lid sealed and the inlet screened so mosquitoes cannot breed, and treat it as water for plants, not for drinking.

Can I leave my rain barrel out all winter? Drain it or disconnect it from the diverter before a hard freeze. A full barrel can crack when the water freezes, and Central Texas still gets a few of those nights most winters.