Mont Belvieu, TX rainwater: 51,448 gallons off a roof
Mont Belvieu, TX: gallons off the roof each year
51,448gallons a year
That is a 1,500 sq ft asphalt roof under Mont Belvieu, TX's normal 64.7 inches of rain, about 795 gallons for every inch that falls.
Mont Belvieu, TX gets enough rain in the growing season that a 200 sq ft garden rarely needs topping up, so a tank here is about saving the occasional dry spell, not a summer of watering.
Rainfall: NOAA 1991-2020 climate normals, the Baytown station (8.3 mi away). Mont Belvieu, TX ranks 2nd wettest of the 252 cities covered in Texas.
Month by month in Mont Belvieu
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 4.85 | 3,855 | |
| Feb | 3.78 | 3,004 | |
| Mar | 3.94 | 3,132 | |
| Apr | 4.51 | 3,585 | |
| May | 6.01 | 4,777 | |
| Jun | 7.08 | 5,627 | |
| Jul | 5.49 | 4,363 | |
| Aug | 6.82 | 5,421 | |
| Sep | 6.41 | 5,095 | |
| Oct | 6.13 | 4,872 | |
| Nov | 4.94 | 3,926 | |
| Dec | 4.77 | 3,791 |
Jun is the wettest month (7.08 in, 5,627 gal off the roof); Feb the driest (3.78 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
Which tank size is worth it in Mont Belvieu
Best fit: a 5,000-gallon cistern, which delivers about 0 gallons to the garden in a normal year.
If you set one up, a single 55-gallon barrel is plenty here; spend the money on a first-flush diverter and a screen rather than more storage.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 0 | 50,353 |
| 110 gal | 0 | 50,353 |
| 165 gal | 0 | 50,353 |
| 275 gal | 0 | 50,353 |
| 550 gal | 0 | 50,353 |
| 1,000 gal | 0 | 50,353 |
| 1,500 gal | 0 | 50,353 |
| 2,500 gal | 0 | 50,353 |
| 5,000 gal | 0 | 50,353 |
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