RoofRainYield

Marina, CA rainwater: 13,440 gallons off a roof

Marina, CA: gallons off the roof each year

13,440gallons a year

That is a 1,500 sq ft asphalt roof under Marina, CA's normal 16.9 inches of rain, about 795 gallons for every inch that falls.

Marina, 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 Marina 0.8 Sse station (0.6 mi away). Marina, CA ranks 139th wettest of the 376 cities covered in California.

Month by month in Marina

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.362,671
Feb3.392,694
Mar2.782,210
Apr1.16922398
May0.62493465
Jun0.18143520
Jul0.0540536
Aug0.0972531
Sep0.0756534
Oct0.91723429
Nov1.821,447
Dec2.481,971

Feb is the wettest month (3.39 in, 2,694 gal off the roof); Jul the driest (0.05 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Which tank size is worth it in Marina

Best fit: a 2,500-gallon cistern, which delivers about 3,330 gallons to the garden in a normal year (97.6% 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 gal38512,235
110 gal71311,907
165 gal89711,723
275 gal1,15911,461
550 gal1,43711,183
1,000 gal1,88710,733
1,500 gal2,38710,233
2,500 gal3,3309,290
5,000 gal3,3309,290

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