RoofRainYield

Lebanon, OR rainwater: 35,726 gallons off a roof

Lebanon, OR: gallons off the roof each year

35,726gallons a year

That is a 1,500 sq ft asphalt roof under Lebanon, OR's normal 45.0 inches of rain, about 795 gallons for every inch that falls.

Lebanon, OR has gaps between storms long enough to drain a single barrel. Around 275 gallons of storage catches most of what is worth catching.

Rainfall: NOAA 1991-2020 climate normals, the Lebanon 1.4 Ssw station (1.1 mi away). Lebanon, OR ranks 23rd wettest of the 57 cities covered in Oregon.

Month by month in Lebanon

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan6.335,031
Feb5.064,022
Mar5.234,157
Apr3.923,11654
May2.822,241191
Jun1.961,558298
Jul0.42334490
Aug0.56445473
Sep1.531,216352
Oct3.482,766108
Nov6.755,365
Dec6.895,476

Dec is the wettest month (6.89 in, 5,476 gal off the roof); Jul the driest (0.42 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 Lebanon

Best fit: a 275-gallon tote or tank, which delivers about 1,635 gallons to the garden in a normal year (83.2% of its need).

If you set one up, 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 gal90533,337
110 gal1,19433,048
165 gal1,39132,851
275 gal1,63532,606
550 gal1,72532,516
1,000 gal1,72532,516
1,500 gal1,72532,516
2,500 gal1,72532,516
5,000 gal1,72532,516

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