Choctaw, OK rainwater: 29,106 gallons off a roof
Choctaw, OK: gallons off the roof each year
29,106gallons a year
That is a 1,500 sq ft asphalt roof under Choctaw, OK's normal 36.6 inches of rain, about 795 gallons for every inch that falls.
In Choctaw, 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 Edmond 5ese station (11.0 mi away). Choctaw, OK ranks 27th wettest of the 45 cities covered in Oklahoma.
Month by month in Choctaw
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 1.22 | 970 | |
| Feb | 1.52 | 1,208 | |
| Mar | 2.55 | 2,027 | |
| Apr | 3.80 | 3,020 | 69 |
| May | 4.92 | 3,910 | |
| Jun | 4.31 | 3,426 | 5 |
| Jul | 3.49 | 2,774 | 107 |
| Aug | 3.81 | 3,028 | 67 |
| Sep | 3.33 | 2,647 | 127 |
| Oct | 3.92 | 3,116 | 54 |
| Nov | 1.75 | 1,391 | |
| Dec | 2.00 | 1,590 |
May is the wettest month (4.92 in, 3,910 gal off the roof); Jan the driest (1.22 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 Choctaw
Best fit: one 55-gallon barrel, which delivers about 366 gallons to the garden in a normal year (85.3% of its need).
Before you buy, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Choctaw's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 366 | 27,975 |
| 110 gal | 366 | 27,975 |
| 165 gal | 366 | 27,975 |
| 275 gal | 366 | 27,975 |
| 550 gal | 366 | 27,975 |
| 1,000 gal | 366 | 27,975 |
| 1,500 gal | 366 | 27,975 |
| 2,500 gal | 366 | 27,975 |
| 5,000 gal | 366 | 27,975 |
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