Garden City, KS rainwater: 15,538 gallons off a roof
Rainwater from a roof in Garden City, KS
15,538gallons a year
That is a 1,500 sq ft asphalt roof under Garden City, KS's normal 19.6 inches of rain, about 795 gallons for every inch that falls.
In Garden City, KS 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 Garden City Exp Stn station (2.4 mi away). Garden City, KS ranks 38th wettest of the 38 cities covered in Kansas.
Month by month in Garden City
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.47 | 374 | |
| Feb | 0.59 | 469 | |
| Mar | 1.13 | 898 | |
| Apr | 1.65 | 1,311 | 337 |
| May | 2.79 | 2,218 | 194 |
| Jun | 3.07 | 2,440 | 160 |
| Jul | 3.16 | 2,512 | 148 |
| Aug | 2.80 | 2,225 | 193 |
| Sep | 1.33 | 1,057 | 377 |
| Oct | 1.34 | 1,065 | 375 |
| Nov | 0.49 | 389 | |
| Dec | 0.73 | 580 |
Jul is the wettest month (3.16 in, 2,512 gal off the roof); Jan the driest (0.47 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 Garden City
Best fit: 2 linked 55-gallon barrels, which delivers about 1,546 gallons to the garden in a normal year (86.7% 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 Garden City's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 1,181 | 13,772 |
| 110 gal | 1,546 | 13,408 |
| 165 gal | 1,552 | 13,401 |
| 275 gal | 1,552 | 13,401 |
| 550 gal | 1,552 | 13,401 |
| 1,000 gal | 1,552 | 13,401 |
| 1,500 gal | 1,552 | 13,401 |
| 2,500 gal | 1,552 | 13,401 |
| 5,000 gal | 1,552 | 13,401 |
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 Kansas?
No rainwater harvesting regulations
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