North Mankato, MN rainwater: 26,928 gallons off a roof
North Mankato, MN: gallons off the roof each year
26,928gallons a year
That is a 1,500 sq ft asphalt roof under North Mankato, MN's normal 33.9 inches of rain, about 795 gallons for every inch that falls.
In North Mankato, 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 Mankato station (2.2 mi away). North Mankato, MN ranks 21st wettest of the 103 cities covered in Minnesota.
Month by month in North Mankato
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.99 | 787 | |
| Feb | 0.84 | 668 | |
| Mar | 1.88 | 1,494 | |
| Apr | 3.31 | 2,631 | 130 |
| May | 4.20 | 3,338 | 19 |
| Jun | 5.64 | 4,483 | |
| Jul | 4.26 | 3,386 | 11 |
| Aug | 4.31 | 3,426 | 5 |
| Sep | 3.30 | 2,623 | 131 |
| Oct | 2.37 | 1,884 | 247 |
| Nov | 1.65 | 1,311 | |
| Dec | 1.13 | 898 |
Jun is the wettest month (5.64 in, 4,483 gal off the roof); Feb the driest (0.84 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 North Mankato
Best fit: one 55-gallon barrel, which delivers about 442 gallons to the garden in a normal year (81.5% of its need).
Before you buy, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of North Mankato's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 442 | 25,526 |
| 110 gal | 442 | 25,526 |
| 165 gal | 442 | 25,526 |
| 275 gal | 442 | 25,526 |
| 550 gal | 442 | 25,526 |
| 1,000 gal | 442 | 25,526 |
| 1,500 gal | 442 | 25,526 |
| 2,500 gal | 442 | 25,526 |
| 5,000 gal | 442 | 25,526 |
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