RoofRainYield

Burlington, WA rainwater: 27,707 gallons off a roof

Rainwater from a roof in Burlington, WA

27,707gallons a year

That is a 1,500 sq ft asphalt roof under Burlington, WA's normal 34.9 inches of rain, about 795 gallons for every inch that falls.

In Burlington, 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 Mount Vernon 3.4 W station (3.8 mi away). Burlington, WA ranks 68th wettest of the 91 cities covered in Washington.

Month by month in Burlington

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan4.743,767
Feb3.042,416
Mar3.002,384
Apr2.862,273186
May2.441,939238
Jun1.771,407322
Jul0.99787419
Aug1.09866406
Sep2.111,677279
Oct3.722,95779
Nov5.084,038
Dec4.023,195

Nov is the wettest month (5.08 in, 4,038 gal off the roof); Jul the driest (0.99 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 Burlington

Best fit: 2 linked 55-gallon barrels, which delivers about 1,508 gallons to the garden in a normal year (78.2% 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 Burlington's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,17024,887
110 gal1,50824,549
165 gal1,57124,486
275 gal1,57124,486
550 gal1,57124,486
1,000 gal1,57124,486
1,500 gal1,57124,486
2,500 gal1,57124,486
5,000 gal1,57124,486

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