Anoka, MN rainwater: 26,237 gallons off a roof

Rainwater from a roof in Anoka, MN

In Anoka, 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 Maple Grove 2.9 Ne station (5.4 mi away). Anoka, MN ranks 46th wettest of the 103 cities covered in Minnesota.

Month by month in Anoka

Jun is the wettest month (4.63 in, 3,680 gal off the roof); Jan the driest (0.78 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 Anoka

Best fit: one 55-gallon barrel, which delivers about 409 gallons to the garden in a normal year (82.4% 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 Anoka's roof water will pass straight through it.

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