RoofRainYield

Dana Point, CA rainwater: 10,078 gallons off a roof

Dana Point, CA: gallons off the roof each year

10,078gallons a year

That is a 1,500 sq ft asphalt roof under Dana Point, CA's normal 12.7 inches of rain, about 795 gallons for every inch that falls.

Dana Point, 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 Laguna Beach station (7.0 mi away). Dana Point, CA ranks 245th wettest of the 376 cities covered in California.

Month by month in Dana Point

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.782,210
Feb3.392,694
Mar1.621,288
Apr0.80636443
May0.20159517
Jun0.1187529
Jul0.1187529
Aug0.0216540
Sep0.16127522
Oct0.49389481
Nov1.13898
Dec1.871,486

Feb is the wettest month (3.39 in, 2,694 gal off the roof); Aug the driest (0.02 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 Dana Point

Best fit: a 2,500-gallon cistern, which delivers about 3,259 gallons to the garden in a normal year (91.5% 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 gal3309,188
110 gal6168,902
165 gal8158,703
275 gal1,0348,484
550 gal1,3098,209
1,000 gal1,7597,759
1,500 gal2,2597,259
2,500 gal3,2596,259
5,000 gal3,4816,036

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