RoofRainYield

Boone, IA rainwater: 31,109 gallons off a roof

Rainwater from a roof in Boone, IA

31,109gallons a year

That is a 1,500 sq ft asphalt roof under Boone, IA's normal 39.1 inches of rain, about 795 gallons for every inch that falls.

In Boone, IA 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 Boone station (1.1 mi away). Boone, IA ranks 2nd wettest of the 41 cities covered in Iowa.

Month by month in Boone

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.20954
Feb1.411,121
Mar2.261,796
Apr4.063,22736
May5.174,109
Jun5.384,276
Jul4.803,815
Aug4.923,910
Sep3.322,639128
Oct2.972,361172
Nov2.081,653
Dec1.571,248

Jun is the wettest month (5.38 in, 4,276 gal off the roof); Jan the driest (1.20 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 Boone?

Best fit: one 55-gallon barrel, which delivers about 269 gallons to the garden in a normal year (79.9% 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 Boone's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal26929,789
110 gal26929,789
165 gal26929,789
275 gal26929,789
550 gal26929,789
1,000 gal26929,789
1,500 gal26929,789
2,500 gal26929,789
5,000 gal26929,789

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 Iowa?

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