Dayton, MN rainwater: 26,237 gallons off a roof
Dayton, MN: gallons off the roof each year
26,237gallons a year
That is a 1,500 sq ft asphalt roof under Dayton, MN's normal 33.0 inches of rain, about 795 gallons for every inch that falls.
In Dayton, 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 Maple Grove 2.9 Ne station (4.2 mi away). Dayton, MN ranks 47th wettest of the 103 cities covered in Minnesota.
Month by month in Dayton
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.78 | 620 | |
| Feb | 0.96 | 763 | |
| Mar | 1.68 | 1,335 | |
| Apr | 3.12 | 2,480 | 153 |
| May | 4.25 | 3,378 | 12 |
| Jun | 4.63 | 3,680 | |
| Jul | 4.36 | 3,465 | |
| Aug | 4.41 | 3,505 | |
| Sep | 3.21 | 2,551 | 142 |
| Oct | 2.84 | 2,257 | 188 |
| Nov | 1.65 | 1,311 | |
| Dec | 1.12 | 890 |
Jun is the wettest month (4.63 in, 3,680 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 Dayton
Best fit: one 55-gallon barrel, which delivers about 414 gallons to the garden in a normal year (83.4% 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 Dayton's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 414 | 25,013 |
| 110 gal | 414 | 25,013 |
| 165 gal | 414 | 25,013 |
| 275 gal | 414 | 25,013 |
| 550 gal | 414 | 25,013 |
| 1,000 gal | 414 | 25,013 |
| 1,500 gal | 414 | 25,013 |
| 2,500 gal | 414 | 25,013 |
| 5,000 gal | 414 | 25,013 |
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