RoofRainYield

New Hope, MN rainwater: 27,564 gallons off a roof

Rainwater from a roof in New Hope, MN

27,564gallons a year

That is a 1,500 sq ft asphalt roof under New Hope, MN's normal 34.7 inches of rain, about 795 gallons for every inch that falls.

In New Hope, 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 New Hope station (1.8 mi away). New Hope, MN ranks 10th wettest of the 103 cities covered in Minnesota.

Month by month in New Hope

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.95755
Feb1.02811
Mar1.881,494
Apr3.312,631130
May4.493,569
Jun4.643,688
Jul4.513,585
Aug4.183,32221
Sep3.452,742112
Oct2.982,369171
Nov1.871,486
Dec1.401,113

Jun is the wettest month (4.64 in, 3,688 gal off the roof); Jan the driest (0.95 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 New Hope

Best fit: one 55-gallon barrel, which delivers about 344 gallons to the garden in a normal year (79.3% of its need).

If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of New Hope's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal34426,215
110 gal34426,215
165 gal34426,215
275 gal34426,215
550 gal34426,215
1,000 gal34426,215
1,500 gal34426,215
2,500 gal34426,215
5,000 gal34426,215

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