RoofRainYield

Cookeville, TN rainwater: 47,394 gallons off a roof

How much rain a roof in Cookeville, TN collects

47,394gallons a year

That is a 1,500 sq ft asphalt roof under Cookeville, TN's normal 59.6 inches of rain, about 795 gallons for every inch that falls.

In Cookeville, TN 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 Cookeville 3.3 Ssw station (2.5 mi away). Cookeville, TN ranks 7th wettest of the 65 cities covered in Tennessee.

Month by month in Cookeville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan5.234,157
Feb5.594,443
Mar5.564,419
Apr5.294,205
May5.094,046
Jun5.224,149
Jul5.214,141
Aug4.223,35416
Sep4.273,39410
Oct3.442,734113
Nov4.523,593
Dec5.994,761

Dec is the wettest month (5.99 in, 4,761 gal off the roof); Oct the driest (3.44 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 Cookeville?

Best fit: one 55-gallon barrel, which delivers about 113 gallons to the garden in a normal year (80.9% 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 Cookeville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal11345,902
110 gal11345,902
165 gal11345,902
275 gal11345,902
550 gal11345,902
1,000 gal11345,902
1,500 gal11345,902
2,500 gal11345,902
5,000 gal11345,902

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 Tennessee?

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