RoofRainYield

Lincoln, CA rainwater: 19,044 gallons off a roof

Rainwater from a roof in Lincoln, CA

19,044gallons a year

That is a 1,500 sq ft asphalt roof under Lincoln, CA's normal 24.0 inches of rain, about 795 gallons for every inch that falls.

Lincoln, CA's rain arrives in a wet season and stops, so storage is what matters. It takes a cistern of 1,500 gallons to carry spring rain into the dry months.

Rainfall: NOAA 1991-2020 climate normals, the Rocklin 2.5 W station (4.6 mi away). Lincoln, CA ranks 57th wettest of the 376 cities covered in California.

Month by month in Lincoln

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan4.443,529
Feb5.054,014
Mar2.822,241
Apr1.951,550299
May1.301,033380
Jun0.37294496
Jul0.000542
Aug0.0648535
Sep0.21167516
Oct1.10874405
Nov2.722,162
Dec3.943,132

Feb is the wettest month (5.05 in, 4,014 gal off the roof); Jul the driest (0.00 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 Lincoln?

Best fit: a 1,500-gallon cistern, which delivers about 2,750 gallons to the garden in a normal year (86.6% of its need).

Before you buy, 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 gal66917,606
110 gal1,06217,214
165 gal1,27017,006
275 gal1,52116,755
550 gal1,80016,476
1,000 gal2,25016,026
1,500 gal2,75015,526
2,500 gal3,02815,248
5,000 gal3,02815,248

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