Mendota Heights, MN rainwater: 25,132 gallons off a roof
How much rain a roof in Mendota Heights, MN collects
25,132gallons a year
That is a 1,500 sq ft asphalt roof under Mendota Heights, MN's normal 31.6 inches of rain, about 795 gallons for every inch that falls.
In Mendota Heights, 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 Minneapolis/St Paul Ap station (4.7 mi away). Mendota Heights, MN ranks 70th wettest of the 103 cities covered in Minnesota.
Month by month in Mendota Heights
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.89 | 707 | |
| Feb | 0.87 | 691 | |
| Mar | 1.68 | 1,335 | |
| Apr | 2.91 | 2,313 | 180 |
| May | 3.91 | 3,108 | 55 |
| Jun | 4.58 | 3,640 | |
| Jul | 4.06 | 3,227 | 36 |
| Aug | 4.34 | 3,449 | 1 |
| Sep | 3.02 | 2,400 | 166 |
| Oct | 2.58 | 2,051 | 221 |
| Nov | 1.61 | 1,280 | |
| Dec | 1.17 | 930 |
Jun is the wettest month (4.58 in, 3,640 gal off the roof); Feb the driest (0.87 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 Mendota Heights
Best fit: one 55-gallon barrel, which delivers about 537 gallons to the garden in a normal year (81.6% 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 Mendota Heights's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 537 | 23,650 |
| 110 gal | 537 | 23,650 |
| 165 gal | 537 | 23,650 |
| 275 gal | 537 | 23,650 |
| 550 gal | 537 | 23,650 |
| 1,000 gal | 537 | 23,650 |
| 1,500 gal | 537 | 23,650 |
| 2,500 gal | 537 | 23,650 |
| 5,000 gal | 537 | 23,650 |
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