RoofRainYield

Hartford, WI rainwater: 27,095 gallons off a roof

How much rain a roof in Hartford, WI collects

27,095gallons a year

That is a 1,500 sq ft asphalt roof under Hartford, WI's normal 34.1 inches of rain, about 795 gallons for every inch that falls.

In Hartford, WI 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 Hartford Wwtp station (1.8 mi away). Hartford, WI ranks 65th wettest of the 98 cities covered in Wisconsin.

Month by month in Hartford

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.521,208
Feb1.261,001
Mar1.781,415
Apr3.432,726115
May3.823,03666
Jun4.773,791
Jul3.893,09257
Aug3.742,97376
Sep3.232,567140
Oct2.912,313180
Nov2.061,637
Dec1.681,335

Jun is the wettest month (4.77 in, 3,791 gal off the roof); Feb the driest (1.26 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Which tank size is worth it in Hartford

Best fit: one 55-gallon barrel, which delivers about 501 gallons to the garden in a normal year (79.1% 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 Hartford's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal50125,529
110 gal50125,529
165 gal50125,529
275 gal50125,529
550 gal50125,529
1,000 gal50125,529
1,500 gal50125,529
2,500 gal50125,529
5,000 gal50125,529

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 Wisconsin?

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