RoofRainYield

Murrieta, CA rainwater: 11,016 gallons off a roof

How much rain a roof in Murrieta, CA collects

11,016gallons a year

That is a 1,500 sq ft asphalt roof under Murrieta, CA's normal 13.9 inches of rain, about 795 gallons for every inch that falls.

Murrieta, CA's rain arrives in a wet season and stops, so storage is what matters. It takes a cistern of 2,500 gallons to carry spring rain into the dry months.

Rainfall: NOAA 1991-2020 climate normals, the Murrieta 3.6 Nne station (2.4 mi away). Murrieta, CA ranks 212th wettest of the 376 cities covered in California.

Month by month in Murrieta

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.662,114
Feb3.072,440
Mar2.351,868
Apr1.22970390
May0.30238505
Jun0.1187529
Jul0.13103526
Aug0.1295527
Sep0.27215509
Oct0.63501464
Nov1.08858
Dec1.921,526

Feb is the wettest month (3.07 in, 2,440 gal off the roof); Jun the driest (0.11 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 Murrieta?

Best fit: a 2,500-gallon cistern, which delivers about 3,221 gallons to the garden in a normal year (93.4% of its need).

If you set one up, 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 gal2759,895
110 gal5319,639
165 gal7519,419
275 gal9969,174
550 gal1,2718,899
1,000 gal1,7218,449
1,500 gal2,2217,949
2,500 gal3,2216,949
5,000 gal3,3936,778

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