RoofRainYield

Fife, WA rainwater: 32,436 gallons off a roof

Rainwater from a roof in Fife, WA

32,436gallons a year

That is a 1,500 sq ft asphalt roof under Fife, WA's normal 40.8 inches of rain, about 795 gallons for every inch that falls.

Fife, WA has gaps between storms long enough to drain a single barrel. Around 165 gallons of storage catches most of what is worth catching.

Rainfall: NOAA 1991-2020 climate normals, the Tacoma #1 station (3.1 mi away). Fife, WA ranks 50th wettest of the 91 cities covered in Washington.

Month by month in Fife

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan6.034,793
Feb4.033,203
Mar4.383,481
Apr3.392,694120
May2.001,590293
Jun1.421,129365
Jul0.55437474
Aug0.83660439
Sep1.571,248347
Oct4.093,25132
Nov6.505,166
Dec6.024,785

Nov is the wettest month (6.50 in, 5,166 gal off the roof); Jul the driest (0.55 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 Fife?

Best fit: 3 linked 55-gallon barrels, which delivers about 1,661 gallons to the garden in a normal year (80.3% of its need).

If you buy one, link barrels with a short hose at the base so they fill and drain together, and check the overflow points away from the house.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,01929,947
110 gal1,43929,527
165 gal1,66129,305
275 gal1,81429,152
550 gal1,81429,152
1,000 gal1,81429,152
1,500 gal1,81429,152
2,500 gal1,81429,152
5,000 gal1,81429,152

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 Washington?

Collecting and storing rooftop rainwater for use on site needs no water right permit, provided the roof is part of a fixed above-ground structure whose primary purpose is not rain collection. Ecology may set local restrictions on new systems if they harm instream values or existing water rights. No state storage cap in the policy.

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