Rock Springs, WY rainwater: 8,147 gallons off a roof
Rock Springs, WY: gallons off the roof each year
8,147gallons a year
That is a 1,500 sq ft asphalt roof under Rock Springs, WY's normal 10.3 inches of rain, about 795 gallons for every inch that falls.
Rock Springs, WY has gaps between storms long enough to drain a single barrel. Around 165 gallons of storage catches most of what is worth catching.
Rainfall: NOAA 1991-2020 climate normals, the Rock Springs 0.9 S station (0.7 mi away). Rock Springs, WY ranks 10th wettest of the 11 cities covered in Wyoming.
Month by month in Rock Springs
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.41 | 326 | |
| Feb | 0.63 | 501 | |
| Mar | 0.60 | 477 | |
| Apr | 1.14 | 906 | 400 |
| May | 1.74 | 1,383 | 325 |
| Jun | 0.83 | 660 | 439 |
| Jul | 0.94 | 747 | 425 |
| Aug | 0.73 | 580 | 451 |
| Sep | 1.03 | 819 | 414 |
| Oct | 0.93 | 739 | 426 |
| Nov | 0.63 | 501 | |
| Dec | 0.64 | 509 |
May is the wettest month (1.74 in, 1,383 gal off the roof); Jan the driest (0.41 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 Rock Springs
Best fit: 3 linked 55-gallon barrels, which delivers about 2,483 gallons to the garden in a normal year (86.2% of its need).
If you set one up, link barrels with a short hose at the base so they fill and drain together, and check the overflow points away from the house.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 1,155 | 6,542 |
| 110 gal | 2,085 | 5,611 |
| 165 gal | 2,483 | 5,214 |
| 275 gal | 2,616 | 5,081 |
| 550 gal | 2,616 | 5,081 |
| 1,000 gal | 2,616 | 5,081 |
| 1,500 gal | 2,616 | 5,081 |
| 2,500 gal | 2,616 | 5,081 |
| 5,000 gal | 2,616 | 5,081 |
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 Wyoming?
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