Underground Precast Rainwater Collection Systems

Durable, Hidden Water Storage Built to Last Decades

Utility water costs keep rising, but rainwater is completely free. Instead of cluttering your yard with small, unsightly above-ground plastic barrels, a Barger Precast underground rainwater system gives you massive, hidden water storage for your lawn, garden, or irrigation needs.

Why Choose an Underground Precast System?

  • Out of Sight & Out of Mind: Installed completely below ground, preserving your lawn’s curb appeal.
  • Heavy-Duty Concrete: Built with the same high-strength precast concrete as our utility vaults—engineered to handle soil load and deliver decades of watertight performance.
  • Large Capacity: Easily store thousands of gallons so your landscape stays green through extended dry spells.
  • Seamless Setup: Plumbs directly into your existing gutter downspouts (ideal during new home construction or retrofitted to existing homes).

 

How Much Storage Capacity Do You Need?

To give you an accurate quote, all we need to know is your target storage capacity in gallons.

If you aren’t sure of your exact number, here is a quick rule of thumb to help you estimate:

Quick Estimation Rule

Every 1,000 sq. ft. of roof collects roughly 600 gallons of water from just 1 inch of rain.

House Footprint (Sq. Ft.)

1″ Rain Harvest

Recommended Starting Storage

1,000 sq. ft.

~600 gallons

1,200 – 1,500 gallons

2,000 sq. ft.

~1,250 gallons

2,500 – 3,000 gallons

3,000 sq. ft.

~1,870 gallons

3,500 – 4,000 gallons

4,000 sq. ft.

~2,500 gallons

5,000+ gallons

Tip: For lawn irrigation, we generally recommend sizing your system to hold at least 2 weeks of watering capacity (roughly 1″ of rain coverage for your lawn).

Ready to Get Started?

Once you have a target gallon size in mind (or if you’d like our team to help you calculate it), contact us to request a custom precast tank quote!