RoofRainYield

Salem, UT rainwater: 16,047 gallons off a roof

How much rain a roof in Salem, UT collects

16,047gallons a year

That is a 1,500 sq ft asphalt roof under Salem, UT's normal 20.2 inches of rain, about 795 gallons for every inch that falls.

Salem, 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 Spanish Fk Pwr House station (3.7 mi away). Salem, UT ranks 28th wettest of the 67 cities covered in Utah.

Month by month in Salem

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.111,677
Feb2.081,653
Mar2.161,717
Apr2.471,963234
May2.111,677279
Jun0.97771421
Jul0.57453471
Aug0.74588450
Sep1.401,113368
Oct1.811,439317
Nov1.801,431
Dec1.971,566

Apr is the wettest month (2.47 in, 1,963 gal off the roof); Jul the driest (0.57 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 Salem?

Best fit: 3 linked 55-gallon barrels, which delivers about 2,093 gallons to the garden in a normal year (82.4% of its need).

If you set one up, 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 gal1,22714,010
110 gal1,78913,448
165 gal2,09313,144
275 gal2,25212,985
550 gal2,25212,985
1,000 gal2,25212,985
1,500 gal2,25212,985
2,500 gal2,25212,985
5,000 gal (over cap)2,25212,985

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