Owasso, OK rainwater: 34,256 gallons off a roof
Rainwater from a roof in Owasso, OK
34,256gallons a year
That is a 1,500 sq ft asphalt roof under Owasso, OK's normal 43.1 inches of rain, about 795 gallons for every inch that falls.
In Owasso, 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 Owasso 1.8 Se station (2.1 mi away). Owasso, OK ranks 12th wettest of the 45 cities covered in Oklahoma.
Month by month in Owasso
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 1.56 | 1,240 | |
| Feb | 1.74 | 1,383 | |
| Mar | 3.25 | 2,583 | |
| Apr | 4.44 | 3,529 | |
| May | 6.13 | 4,872 | |
| Jun | 5.26 | 4,181 | |
| Jul | 4.20 | 3,338 | 19 |
| Aug | 3.50 | 2,782 | 106 |
| Sep | 3.82 | 3,036 | 66 |
| Oct | 3.83 | 3,044 | 65 |
| Nov | 2.87 | 2,281 | |
| Dec | 2.50 | 1,987 |
May is the wettest month (6.13 in, 4,872 gal off the roof); Jan the driest (1.56 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 Owasso
Best fit: one 55-gallon barrel, which delivers about 212 gallons to the garden in a normal year (82.9% 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 Owasso's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 212 | 33,129 |
| 110 gal | 212 | 33,129 |
| 165 gal | 212 | 33,129 |
| 275 gal | 212 | 33,129 |
| 550 gal | 212 | 33,129 |
| 1,000 gal | 212 | 33,129 |
| 1,500 gal | 212 | 33,129 |
| 2,500 gal | 212 | 33,129 |
| 5,000 gal | 212 | 33,129 |
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