Durant, OK rainwater: 35,250 gallons off a roof
Rainwater from a roof in Durant, OK
35,250gallons a year
That is a 1,500 sq ft asphalt roof under Durant, OK's normal 44.3 inches of rain, about 795 gallons for every inch that falls.
In Durant, 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 Durant station (1.4 mi away). Durant, OK ranks 6th wettest of the 45 cities covered in Oklahoma.
Month by month in Durant
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.50 | 1,987 | |
| Feb | 2.58 | 2,051 | |
| Mar | 4.04 | 3,211 | |
| Apr | 3.92 | 3,116 | 54 |
| May | 5.42 | 4,308 | |
| Jun | 5.06 | 4,022 | |
| Jul | 3.28 | 2,607 | 133 |
| Aug | 2.41 | 1,915 | 242 |
| Sep | 3.83 | 3,044 | 65 |
| Oct | 4.44 | 3,529 | |
| Nov | 3.53 | 2,806 | |
| Dec | 3.34 | 2,655 |
May is the wettest month (5.42 in, 4,308 gal off the roof); Aug the driest (2.41 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 Durant
Best fit: one 55-gallon barrel, which delivers about 403 gallons to the garden in a normal year (81.6% 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 Durant's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 403 | 33,976 |
| 110 gal | 434 | 33,946 |
| 165 gal | 434 | 33,946 |
| 275 gal | 434 | 33,946 |
| 550 gal | 434 | 33,946 |
| 1,000 gal | 434 | 33,946 |
| 1,500 gal | 434 | 33,946 |
| 2,500 gal | 434 | 33,946 |
| 5,000 gal | 434 | 33,946 |
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