Is a rainwater collection
system right for me?

Many factors go into finding the right rainwater harvesting system for you. Here are some of the factors we look for:

Roof Size

Although any roof size will work, optimal roof size for a whole-home supply begins around 2000 square feet. One square foot of roof captures approximately .6 gallons of rainwater per inch of rainfall, so a 2000 square foot roof would generate 1,200 gallons of rainwater per inch of rainfall. With an average rainfall in the Texas Hill Country of 34 inches, a 2000 square foot roof would generate 40,800 gallons of water, ample rain to keep your tank stocked between rainfall, even with use. Bigger roofs generate water and restock your tank more quickly. A smaller roof doesn’t necessarily mean you can’t choose rainwater, but you may be less likely to keep a full tank.

How much rainwater will my roof generate?

Roof Material

Metal roofs are the ideal roofing material for rainwater capture. A smooth metal surface lets water flow quicker, and is less likely to gather dust, pollen, or contaminants. When working with other roof materials such as concrete or asphalt shingles, we typically recommend a first flush diversion system to capture the rain only after there’s been a 1/8” or so of rainfall to wash the surface down first.


While rainwater harvesting is legal and encouraged in Texas, many Home Owner’s Associations and housing developments have rules on tank color, visibility, and distance from neighboring properties. It’s important to know your HOA’s rules before building your rainwater system.

Tank Location

Your Pioneer rainwater tank requires a pad upwards of 30 feet in diameter, and eight feet of clearance height. We also look for a stable surface with little erosion potential. While there is potential to build on a level concrete pad or ring beam, building on sand provides a more environmentally and economically beneficial surface.

Tank Size

We work with you to find the perfect sized Pioneer rainwater tank to fit your needs. Generally, multiplying your roof size by ten will estimate the minimum water storage you should have. For example, a 3000 square foot roof might use a Pioneer XL23 (30,000 gallons). In addition to your roof size, we also take into account how many people the water will be serving, and how you plan to use your rainwater. For many, a rainwater system may only be used for potable drinking water, while others may use their rainwater for watering gardens, filling pools, and hydrating livestock. Making sure you have the right size tank means less water wasted.

Read More about how Texas House Bill No. 3391 protects and encourages Texas property owners’ rights to rainwater harvesting

Texas Water Development Board’s The Texas Manual on Rainwater Harvesting

Would you like an evaluation of your property or project for a rainwater harvesting system? Get in touch today!