Rosemount, MN rainwater: 27,119 gallons off a roof
Rosemount, MN: gallons off the roof each year
27,119gallons a year
That is a 1,500 sq ft asphalt roof under Rosemount, MN's normal 34.1 inches of rain, about 795 gallons for every inch that falls.
In Rosemount, 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 Rosemount Rsch & Outreach Ctr station (2.5 mi away). Rosemount, MN ranks 14th wettest of the 103 cities covered in Minnesota.
Month by month in Rosemount
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.96 | 763 | |
| Feb | 0.90 | 715 | |
| Mar | 1.80 | 1,431 | |
| Apr | 3.10 | 2,464 | 156 |
| May | 4.32 | 3,434 | 4 |
| Jun | 4.88 | 3,879 | |
| Jul | 4.51 | 3,585 | |
| Aug | 4.43 | 3,521 | |
| Sep | 3.44 | 2,734 | 113 |
| Oct | 2.86 | 2,273 | 186 |
| Nov | 1.71 | 1,359 | |
| Dec | 1.21 | 962 |
Jun is the wettest month (4.88 in, 3,879 gal off the roof); Feb the driest (0.90 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 Rosemount
Best fit: one 55-gallon barrel, which delivers about 383 gallons to the garden in a normal year (83.5% 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 Rosemount's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 383 | 25,836 |
| 110 gal | 383 | 25,836 |
| 165 gal | 383 | 25,836 |
| 275 gal | 383 | 25,836 |
| 550 gal | 383 | 25,836 |
| 1,000 gal | 383 | 25,836 |
| 1,500 gal | 383 | 25,836 |
| 2,500 gal | 383 | 25,836 |
| 5,000 gal | 383 | 25,836 |
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