Eagan, MN rainwater: 27,079 gallons off a roof
How much rain a roof in Eagan, MN collects
27,079gallons a year
That is a 1,500 sq ft asphalt roof under Eagan, MN's normal 34.1 inches of rain, about 795 gallons for every inch that falls.
In Eagan, 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 Rosemount 3.3 Wnw station (4.1 mi away). Eagan, MN ranks 15th wettest of the 103 cities covered in Minnesota.
Month by month in Eagan
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 0.88 | 699 | |
| Feb | 0.95 | 755 | |
| Mar | 1.77 | 1,407 | |
| Apr | 3.21 | 2,551 | 142 |
| May | 4.24 | 3,370 | 14 |
| Jun | 4.99 | 3,966 | |
| Jul | 4.60 | 3,656 | |
| Aug | 4.41 | 3,505 | |
| Sep | 3.45 | 2,742 | 112 |
| Oct | 2.73 | 2,170 | 202 |
| Nov | 1.65 | 1,311 | |
| Dec | 1.19 | 946 |
Jun is the wettest month (4.99 in, 3,966 gal off the roof); Jan the driest (0.88 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
Barrel or cistern in Eagan?
Best fit: one 55-gallon barrel, which delivers about 387 gallons to the garden in a normal year (82.3% 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 Eagan's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 387 | 25,747 |
| 110 gal | 387 | 25,747 |
| 165 gal | 387 | 25,747 |
| 275 gal | 387 | 25,747 |
| 550 gal | 387 | 25,747 |
| 1,000 gal | 387 | 25,747 |
| 1,500 gal | 387 | 25,747 |
| 2,500 gal | 387 | 25,747 |
| 5,000 gal | 387 | 25,747 |
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