Shakopee, MN rainwater: 26,864 gallons off a roof
Rainwater from a roof in Shakopee, MN
26,864gallons a year
That is a 1,500 sq ft asphalt roof under Shakopee, MN's normal 33.8 inches of rain, about 795 gallons for every inch that falls.
In Shakopee, 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 Prior Lake 2.0 W station (4.1 mi away). Shakopee, MN ranks 22nd wettest of the 103 cities covered in Minnesota.
Month by month in Shakopee
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.95 | 755 | |
| Feb | 1.02 | 811 | |
| Mar | 1.88 | 1,494 | |
| Apr | 3.13 | 2,488 | 152 |
| May | 4.33 | 3,442 | 2 |
| Jun | 4.78 | 3,799 | |
| Jul | 4.25 | 3,378 | 12 |
| Aug | 4.56 | 3,624 | |
| Sep | 3.22 | 2,559 | 141 |
| Oct | 2.72 | 2,162 | 203 |
| Nov | 1.71 | 1,359 | |
| Dec | 1.25 | 994 |
Jun is the wettest month (4.78 in, 3,799 gal off the roof); Jan the driest (0.95 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 Shakopee
Best fit: one 55-gallon barrel, which delivers about 421 gallons to the garden in a normal year (82.4% 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 Shakopee's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 421 | 25,618 |
| 110 gal | 421 | 25,618 |
| 165 gal | 421 | 25,618 |
| 275 gal | 421 | 25,618 |
| 550 gal | 421 | 25,618 |
| 1,000 gal | 421 | 25,618 |
| 1,500 gal | 421 | 25,618 |
| 2,500 gal | 421 | 25,618 |
| 5,000 gal | 421 | 25,618 |
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