RoofRainYield

Great Bend, KS rainwater: 21,698 gallons off a roof

Rainwater from a roof in Great Bend, KS

21,698gallons a year

That is a 1,500 sq ft asphalt roof under Great Bend, KS's normal 27.3 inches of rain, about 795 gallons for every inch that falls.

In Great Bend, KS 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 Great Bend 3w station (1.6 mi away). Great Bend, KS ranks 34th wettest of the 38 cities covered in Kansas.

Month by month in Great Bend

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.71564
Feb0.89707
Mar1.561,240
Apr2.151,709274
May4.833,839
Jun3.662,90986
Jul3.863,06861
Aug3.692,93382
Sep1.981,574295
Oct1.961,558298
Nov1.00795
Dec1.01803

May is the wettest month (4.83 in, 3,839 gal off the roof); Jan the driest (0.71 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 Great Bend?

Best fit: 2 linked 55-gallon barrels, which delivers about 950 gallons to the garden in a normal year (86.6% 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 Great Bend's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal81520,194
110 gal95020,058
165 gal95020,058
275 gal95020,058
550 gal95020,058
1,000 gal95020,058
1,500 gal95020,058
2,500 gal95020,058
5,000 gal95020,058

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 Kansas?

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