RoofRainYield

Vernal, UT rainwater: 7,217 gallons off a roof

Rainwater from a roof in Vernal, UT

7,217gallons a year

That is a 1,500 sq ft asphalt roof under Vernal, UT's normal 9.1 inches of rain, about 795 gallons for every inch that falls.

Vernal, UT has gaps between storms long enough to drain a single barrel. Around 165 gallons of storage catches most of what is worth catching.

Rainfall: NOAA 1991-2020 climate normals, the Vernal station (0.8 mi away). Vernal, UT ranks 67th wettest of the 67 cities covered in Utah.

Month by month in Vernal

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.62493
Feb0.56445
Mar0.68540
Apr0.75596449
May1.04827413
Jun0.59469469
Jul0.54429475
Aug0.81644441
Sep1.22970390
Oct1.15914399
Nov0.51405
Dec0.61485

Sep is the wettest month (1.22 in, 970 gal off the roof); Nov the driest (0.51 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

What size rain barrel for Vernal

Best fit: 3 linked 55-gallon barrels, which delivers about 2,511 gallons to the garden in a normal year (82.7% of its need).

Before you buy, link barrels with a short hose at the base so they fill and drain together, and check the overflow points away from the house.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,0455,752
110 gal2,0094,788
165 gal2,5114,285
275 gal2,7834,014
550 gal2,7834,014
1,000 gal2,7834,014
1,500 gal2,7834,014
2,500 gal2,7834,014
5,000 gal (over cap)2,7833,028

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 Utah?

Up to 2 covered containers of max 100 gal each with no registration; with free registration at the Utah Division of Water Rights, total storage up to 2,500 gal. Use limited to the same parcel where captured.

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