Columbia Heights, MN rainwater: 26,213 gallons off a roof
How much rain a roof in Columbia Heights, MN collects
26,213gallons a year
That is a 1,500 sq ft asphalt roof under Columbia Heights, MN's normal 33.0 inches of rain, about 795 gallons for every inch that falls.
In Columbia 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 Roseville 2.1 Nw station (3.1 mi away). Columbia Heights, MN ranks 50th wettest of the 103 cities covered in Minnesota.
Month by month in Columbia Heights
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.85 | 676 | |
| Feb | 0.93 | 739 | |
| Mar | 1.62 | 1,288 | |
| Apr | 2.99 | 2,376 | 170 |
| May | 4.28 | 3,402 | 9 |
| Jun | 4.49 | 3,569 | |
| Jul | 4.37 | 3,473 | |
| Aug | 4.38 | 3,481 | |
| Sep | 3.25 | 2,583 | 137 |
| Oct | 2.79 | 2,218 | 194 |
| Nov | 1.76 | 1,399 | |
| Dec | 1.27 | 1,009 |
Jun is the wettest month (4.49 in, 3,569 gal off the roof); Jan the driest (0.85 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 Columbia Heights
Best fit: one 55-gallon barrel, which delivers about 403 gallons to the garden in a normal year (79.0% 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 Columbia Heights's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 403 | 24,805 |
| 110 gal | 403 | 24,805 |
| 165 gal | 403 | 24,805 |
| 275 gal | 403 | 24,805 |
| 550 gal | 403 | 24,805 |
| 1,000 gal | 403 | 24,805 |
| 1,500 gal | 403 | 24,805 |
| 2,500 gal | 403 | 24,805 |
| 5,000 gal | 403 | 24,805 |
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