Tulsa, OK rainwater: 35,162 gallons off a roof
Tulsa, OK: gallons off the roof each year
35,162gallons a year
That is a 1,500 sq ft asphalt roof under Tulsa, OK's normal 44.2 inches of rain, about 795 gallons for every inch that falls.
In Tulsa, 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 Tulsa 1.4 S station (1.6 mi away). Tulsa, OK ranks 8th wettest of the 45 cities covered in Oklahoma.
Month by month in Tulsa
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.08 | 1,653 | |
| Feb | 1.81 | 1,439 | |
| Mar | 3.58 | 2,845 | |
| Apr | 4.41 | 3,505 | |
| May | 5.68 | 4,514 | |
| Jun | 4.79 | 3,807 | |
| Jul | 4.23 | 3,362 | 15 |
| Aug | 4.28 | 3,402 | 9 |
| Sep | 3.97 | 3,155 | 47 |
| Oct | 3.78 | 3,004 | 71 |
| Nov | 2.96 | 2,353 | |
| Dec | 2.67 | 2,122 |
May is the wettest month (5.68 in, 4,514 gal off the roof); Feb 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.
What size rain barrel for Tulsa
Best fit: one 55-gallon barrel, which delivers about 117 gallons to the garden in a normal year (82.3% of its need).
If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Tulsa's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 117 | 34,130 |
| 110 gal | 117 | 34,130 |
| 165 gal | 117 | 34,130 |
| 275 gal | 117 | 34,130 |
| 550 gal | 117 | 34,130 |
| 1,000 gal | 117 | 34,130 |
| 1,500 gal | 117 | 34,130 |
| 2,500 gal | 117 | 34,130 |
| 5,000 gal | 117 | 34,130 |
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