RoofRainYield

Conway, AR rainwater: 42,125 gallons off a roof

How much rain a roof in Conway, AR collects

42,125gallons a year

That is a 1,500 sq ft asphalt roof under Conway, AR's normal 53.0 inches of rain, about 795 gallons for every inch that falls.

In Conway, AR 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 Conway 2.8 Sse station (2.3 mi away). Conway, AR ranks 13th wettest of the 39 cities covered in Arkansas.

Month by month in Conway

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.682,925
Feb4.173,314
Mar5.104,054
Apr5.584,435
May5.324,228
Jun3.542,814101
Jul3.612,86992
Aug4.273,39410
Sep3.252,583137
Oct4.463,545
Nov4.893,887
Dec5.134,077

Apr is the wettest month (5.58 in, 4,435 gal off the roof); Sep the driest (3.25 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 Conway?

Best fit: one 55-gallon barrel, which delivers about 281 gallons to the garden in a normal year (82.6% 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 Conway's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal28140,778
110 gal28140,778
165 gal28140,778
275 gal28140,778
550 gal28140,778
1,000 gal28140,778
1,500 gal28140,778
2,500 gal28140,778
5,000 gal28140,778

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 Arkansas?

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