Elk City, OK rainwater: 23,463 gallons off a roof

Elk City, OK: gallons off the roof each year

23,463gallons a year

That is a 1,500 sq ft asphalt roof under Elk City, OK's normal 29.5 inches of rain, about 795 gallons for every inch that falls.

In Elk City, OK 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 Elk City 4 W station (4.4 mi away). Elk City, OK ranks 42nd wettest of the 45 cities covered in Oklahoma.

Month by month in Elk City

Month	Rain (in)	Off the roof (gal)	Garden shortfall (gal)
Jan	0.88	699
Feb	1.00	795
Mar	2.10	1,669
Apr	2.74	2,178	201
May	4.45	3,537
Jun	3.77	2,996	72
Jul	2.48	1,971	233
Aug	3.70	2,941	81
Sep	2.80	2,225	193
Oct	2.90	2,305	181
Nov	1.42	1,129
Dec	1.28	1,017

May is the wettest month (4.45 in, 3,537 gal off the roof); Jan the driest (0.88 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 Elk City

Best fit: one 55-gallon barrel, which delivers about 822 gallons to the garden in a normal year (85.5% of its need).

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

Tank	Water used (gal/yr)	Spills over (gal/yr)
55 gal	822	21,906
110 gal	822	21,906
165 gal	822	21,906
275 gal	822	21,906
550 gal	822	21,906
1,000 gal	822	21,906
1,500 gal	822	21,906
2,500 gal	822	21,906
5,000 gal	822	21,906

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 Oklahoma?

Encouraged through state legislation: Water for 2060 Act

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