Red Wing, MN rainwater: 25,760 gallons off a roof
How much rain a roof in Red Wing, MN collects
25,760gallons a year
That is a 1,500 sq ft asphalt roof under Red Wing, MN's normal 32.4 inches of rain, about 795 gallons for every inch that falls.
In Red Wing, MN 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 Red Wing Dam 3 station (2.0 mi away). Red Wing, MN ranks 64th wettest of the 103 cities covered in Minnesota.
Month by month in Red Wing
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.78 | 620 | |
| Feb | 0.88 | 699 | |
| Mar | 1.67 | 1,327 | |
| Apr | 2.88 | 2,289 | 183 |
| May | 4.06 | 3,227 | 36 |
| Jun | 5.09 | 4,046 | |
| Jul | 3.82 | 3,036 | 66 |
| Aug | 4.45 | 3,537 | |
| Sep | 3.66 | 2,909 | 86 |
| Oct | 2.48 | 1,971 | 233 |
| Nov | 1.63 | 1,296 | |
| Dec | 1.01 | 803 |
Jun is the wettest month (5.09 in, 4,046 gal off the roof); Jan the driest (0.78 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 Red Wing
Best fit: one 55-gallon barrel, which delivers about 483 gallons to the garden in a normal year (79.9% 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 Red Wing's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 483 | 24,332 |
| 110 gal | 483 | 24,332 |
| 165 gal | 483 | 24,332 |
| 275 gal | 483 | 24,332 |
| 550 gal | 483 | 24,332 |
| 1,000 gal | 483 | 24,332 |
| 1,500 gal | 483 | 24,332 |
| 2,500 gal | 483 | 24,332 |
| 5,000 gal | 483 | 24,332 |
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 Minnesota?
No statewide rainwater harvesting regulations; check county for local incentives
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