RoofRainYield

Marysville, WA rainwater: 31,991 gallons off a roof

How much rain a roof in Marysville, WA collects

31,991gallons a year

That is a 1,500 sq ft asphalt roof under Marysville, WA's normal 40.3 inches of rain, about 795 gallons for every inch that falls.

In Marysville, WA a single barrel does most of the work. Storms come often enough that a small tank refills before it runs dry, and a bigger one would mostly sit full.

Rainfall: NOAA 1991-2020 climate normals, the Everett station (7.5 mi away). Marysville, WA ranks 53rd wettest of the 91 cities covered in Washington.

Month by month in Marysville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan5.044,006
Feb3.702,941
Mar4.113,267
Apr3.402,702118
May2.702,146206
Jun2.301,828256
Jul1.04827413
Aug1.15914399
Sep2.341,860251
Oct3.702,94181
Nov5.824,626
Dec4.953,934

Nov is the wettest month (5.82 in, 4,626 gal off the roof); Jul the driest (1.04 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 Marysville

Best fit: 2 linked 55-gallon barrels, which delivers about 1,357 gallons to the garden in a normal year (78.8% of its need).

Before you buy, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Marysville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,02829,208
110 gal1,35728,879
165 gal1,40928,826
275 gal1,40928,826
550 gal1,40928,826
1,000 gal1,40928,826
1,500 gal1,40928,826
2,500 gal1,40928,826
5,000 gal1,40928,826

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