RoofRainYield

Del Rio, TX rainwater: 15,729 gallons off a roof

Rainwater from a roof in Del Rio, TX

15,729gallons a year

That is a 1,500 sq ft asphalt roof under Del Rio, TX's normal 19.8 inches of rain, about 795 gallons for every inch that falls.

In Del Rio, TX a single barrel does most of the work. Storms come often enough that a small tank refills before it runs dry, and a bigger one would mostly sit full.

Rainfall: NOAA 1991-2020 climate normals, the Del Rio Intl Ap station (2.7 mi away). Del Rio, TX ranks 236th wettest of the 252 cities covered in Texas.

Month by month in Del Rio

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.61485
Feb0.63501
Mar1.18938
Apr1.501,192355
May3.062,432161
Jun2.321,844253
Jul1.481,176358
Aug2.692,138207
Sep2.632,090214
Oct2.081,653283
Nov0.91723
Dec0.70556

May is the wettest month (3.06 in, 2,432 gal off the roof); Jan the driest (0.61 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Barrel or cistern in Del Rio?

Best fit: 2 linked 55-gallon barrels, which delivers about 1,535 gallons to the garden in a normal year (83.8% of its need).

If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Del Rio's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,12214,157
110 gal1,53513,744
165 gal1,65413,626
275 gal1,66313,617
550 gal1,66313,617
1,000 gal1,66313,617
1,500 gal1,66313,617
2,500 gal1,66313,617
5,000 gal1,66313,617

Simulated storm by storm through a normal year using the station's count of days with 0.1 in or more of rain each month.

Is rainwater collection legal in Texas?

Rainwater harvesting is legal and encouraged; no state storage cap. HOAs may not adopt new covenants banning rainwater harvesting installations but may require screening. Local taxing units may exempt property with water conservation initiatives from property tax (Tax Code 11.32).

Checked against the current source on 2026-11-06. Source