Ashland, OR rainwater: 15,523 gallons off a roof

Ashland, OR: gallons off the roof each year

15,523gallons a year

That is a 1,500 sq ft asphalt roof under Ashland, OR's normal 19.5 inches of rain, about 795 gallons for every inch that falls.

Ashland, OR has gaps between storms long enough to drain a single barrel. Around 550 gallons of storage catches most of what is worth catching.

Rainfall: NOAA 1991-2020 climate normals, the Ashland station (1.7 mi away). Ashland, OR ranks 45th wettest of the 57 cities covered in Oregon.

Month by month in Ashland

Month	Rain (in)	Off the roof (gal)	Garden shortfall (gal)
Jan	2.35	1,868
Feb	2.04	1,621
Mar	2.03	1,613
Apr	1.95	1,550	299
May	1.64	1,303	338
Jun	0.85	676	436
Jul	0.44	350	487
Aug	0.37	294	496
Sep	0.50	397	480
Oct	1.41	1,121	367
Nov	2.57	2,043
Dec	3.38	2,686

Dec is the wettest month (3.38 in, 2,686 gal off the roof); Aug the driest (0.37 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 Ashland

Best fit: a 550-gallon tote or tank, which delivers about 2,585 gallons to the garden in a normal year (89.0% of its need).

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

Tank	Water used (gal/yr)	Spills over (gal/yr)
55 gal	1,121	13,532
110 gal	1,639	13,013
165 gal	1,939	12,714
275 gal	2,287	12,365
550 gal	2,585	12,067
1,000 gal	2,625	12,028
1,500 gal	2,625	12,028
2,500 gal	2,625	12,028
5,000 gal	2,625	12,028

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 Oregon?

Collecting and using rain from an artificial impervious surface (e.g. a rooftop) is an exempt use: no water right application, permit or certificate needed. Statute sets no storage cap in this section.

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