Chubbuck, ID rainwater: 9,641 gallons off a roof

How much rain a roof in Chubbuck, ID collects

9,641gallons a year

That is a 1,500 sq ft asphalt roof under Chubbuck, ID's normal 12.1 inches of rain, about 795 gallons for every inch that falls.

Chubbuck, ID 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 Pocatello 2.5 Ne station (2.3 mi away). Chubbuck, ID ranks 19th wettest of the 26 cities covered in Idaho.

Month by month in Chubbuck

Month	Rain (in)	Off the roof (gal)	Garden shortfall (gal)
Jan	0.97	771
Feb	1.02	811
Mar	1.15	914
Apr	1.47	1,168	359
May	1.56	1,240	348
Jun	1.16	922	398
Jul	0.55	437	474
Aug	0.59	469	469
Sep	1.04	827	413
Oct	1.14	906	400
Nov	0.73	580
Dec	0.75	596

May is the wettest month (1.56 in, 1,240 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.

Which tank size is worth it in Chubbuck

Best fit: 3 linked 55-gallon barrels, which delivers about 2,466 gallons to the garden in a normal year (86.2% 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.

Tank	Water used (gal/yr)	Spills over (gal/yr)
55 gal	1,340	7,656
110 gal	2,173	6,823
165 gal	2,466	6,530
275 gal	2,547	6,449
550 gal	2,547	6,449
1,000 gal	2,547	6,449
1,500 gal	2,547	6,449
2,500 gal	2,547	6,449
5,000 gal	2,547	6,449

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 Idaho?

Allowed through a legal clarification made by the Office of the Attorney General

From the 2015 (Pacific Northwest National Laboratory report 24347); not yet re-checked against current law, so check with your state water agency before building anything large. Source