RoofRainYield

Midland, MI rainwater: 26,554 gallons off a roof

How much rain a roof in Midland, MI collects

26,554gallons a year

That is a 1,500 sq ft asphalt roof under Midland, MI's normal 33.4 inches of rain, about 795 gallons for every inch that falls.

In Midland, MI 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 Midland station (1.9 mi away). Midland, MI ranks 70th wettest of the 90 cities covered in Michigan.

Month by month in Midland

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.011,598
Feb1.921,526
Mar2.001,590
Apr3.482,766108
May3.742,97376
Jun3.712,94980
Jul2.822,241191
Aug3.172,520147
Sep2.822,241191
Oct3.142,496151
Nov2.652,106
Dec1.951,550

May is the wettest month (3.74 in, 2,973 gal off the roof); Feb the driest (1.92 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 Midland?

Best fit: one 55-gallon barrel, which delivers about 759 gallons to the garden in a normal year (80.4% 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 Midland's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal75924,775
110 gal75924,775
165 gal75924,775
275 gal75924,775
550 gal75924,775
1,000 gal75924,775
1,500 gal75924,775
2,500 gal75924,775
5,000 gal75924,775

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 Michigan?

No rainwater harvesting regulations

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