Woodbury, MN rainwater: 23,208 gallons off a roof
How much rain a roof in Woodbury, MN collects
23,208gallons a year
That is a 1,500 sq ft asphalt roof under Woodbury, MN's normal 29.2 inches of rain, about 795 gallons for every inch that falls.
In Woodbury, 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 St Paul Downtown Ap station (6.7 mi away). Woodbury, MN ranks 90th wettest of the 103 cities covered in Minnesota.
Month by month in Woodbury
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.48 | 382 | |
| Feb | 0.52 | 413 | |
| Mar | 1.43 | 1,137 | |
| Apr | 2.58 | 2,051 | 221 |
| May | 3.97 | 3,155 | 47 |
| Jun | 4.63 | 3,680 | |
| Jul | 3.97 | 3,155 | 47 |
| Aug | 4.10 | 3,259 | 31 |
| Sep | 3.08 | 2,448 | 158 |
| Oct | 2.47 | 1,963 | 234 |
| Nov | 1.32 | 1,049 | |
| Dec | 0.65 | 517 |
Jun is the wettest month (4.63 in, 3,680 gal off the roof); Jan the driest (0.48 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 Woodbury
Best fit: one 55-gallon barrel, which delivers about 604 gallons to the garden in a normal year (81.7% 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 Woodbury's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 604 | 21,780 |
| 110 gal | 604 | 21,780 |
| 165 gal | 604 | 21,780 |
| 275 gal | 604 | 21,780 |
| 550 gal | 604 | 21,780 |
| 1,000 gal | 604 | 21,780 |
| 1,500 gal | 604 | 21,780 |
| 2,500 gal | 604 | 21,780 |
| 5,000 gal | 604 | 21,780 |
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