RoofRainYield

Adelanto, CA rainwater: 4,427 gallons off a roof

How much rain a roof in Adelanto, CA collects

4,427gallons a year

That is a 1,500 sq ft asphalt roof under Adelanto, CA's normal 5.6 inches of rain, about 795 gallons for every inch that falls.

Adelanto, CA's rain arrives in a wet season and stops, so storage is what matters. It takes a cistern of 5,000 gallons to carry spring rain into the dry months.

Rainfall: NOAA 1991-2020 climate normals, the Victorville station (9.1 mi away). Adelanto, CA ranks 361st wettest of the 376 cities covered in California.

Month by month in Adelanto

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.97771
Feb1.271,009
Mar0.78620
Apr0.33262501
May0.0972531
Jun0.0432537
Jul0.22175515
Aug0.1187529
Sep0.16127522
Oct0.31246504
Nov0.35278
Dec0.94747

Feb is the wettest month (1.27 in, 1,009 gal off the roof); Jun the driest (0.04 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 Adelanto?

Best fit: a 5,000-gallon cistern, which delivers about 3,590 gallons to the garden in a normal year (98.6% of its need).

If you buy one, ask about a rebate first: cistern-sized storage costs real money, and a buried or tall tank may need a permit. Place it where a full tank (about 8.3 lb a gallon) sits on firm, level ground.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal2203,694
110 gal4403,474
165 gal6553,259
275 gal9143,001
550 gal1,1892,726
1,000 gal1,6392,276
1,500 gal2,1391,776
2,500 gal3,139776
5,000 gal3,5900

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 California?

Legal. Use of rainwater collected from rooftops does not require a water right permit (Rainwater Capture Act of 2012, Water Code 10570 et seq.). The Act does not change existing water rights; local building/plumbing codes still apply to installed systems.

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