RoofRainYield

Forrest City, AR rainwater: 41,155 gallons off a roof

Rainwater from a roof in Forrest City, AR

41,155gallons a year

That is a 1,500 sq ft asphalt roof under Forrest City, AR's normal 51.8 inches of rain, about 795 gallons for every inch that falls.

In Forrest City, 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 Madison 1 Nw station (3.4 mi away). Forrest City, AR ranks 20th wettest of the 39 cities covered in Arkansas.

Month by month in Forrest City

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.893,092
Feb4.203,338
Mar5.554,411
Apr5.634,475
May5.354,252
Jun4.193,33020
Jul3.552,822100
Aug2.932,329177
Sep2.932,329177
Oct4.083,24334
Nov4.383,481
Dec5.104,054

Apr is the wettest month (5.63 in, 4,475 gal off the roof); Aug the driest (2.93 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 Forrest City

Best fit: one 55-gallon barrel, which delivers about 432 gallons to the garden in a normal year (85.1% 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 Forrest City's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal43239,628
110 gal43239,628
165 gal43239,628
275 gal43239,628
550 gal43239,628
1,000 gal43239,628
1,500 gal43239,628
2,500 gal43239,628
5,000 gal43239,628

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