Bixby, OK rainwater: 35,130 gallons off a roof
Bixby, OK: gallons off the roof each year
35,130gallons a year
That is a 1,500 sq ft asphalt roof under Bixby, OK's normal 44.2 inches of rain, about 795 gallons for every inch that falls.
In Bixby, 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 Broken Arrow 2.7 Ssw station (5.5 mi away). Bixby, OK ranks 9th wettest of the 45 cities covered in Oklahoma.
Month by month in Bixby
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 1.81 | 1,439 | |
| Feb | 1.99 | 1,582 | |
| Mar | 3.42 | 2,718 | |
| Apr | 4.50 | 3,577 | |
| May | 6.73 | 5,349 | |
| Jun | 4.99 | 3,966 | |
| Jul | 4.10 | 3,259 | 31 |
| Aug | 3.28 | 2,607 | 133 |
| Sep | 4.04 | 3,211 | 39 |
| Oct | 3.97 | 3,155 | 47 |
| Nov | 2.77 | 2,202 | |
| Dec | 2.60 | 2,066 |
May is the wettest month (6.73 in, 5,349 gal off the roof); Jan the driest (1.81 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 Bixby
Best fit: one 55-gallon barrel, which delivers about 210 gallons to the garden in a normal year (83.8% 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 Bixby's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 210 | 34,020 |
| 110 gal | 210 | 34,020 |
| 165 gal | 210 | 34,020 |
| 275 gal | 210 | 34,020 |
| 550 gal | 210 | 34,020 |
| 1,000 gal | 210 | 34,020 |
| 1,500 gal | 210 | 34,020 |
| 2,500 gal | 210 | 34,020 |
| 5,000 gal | 210 | 34,020 |
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