RoofRainYield

Cleveland, TN rainwater: 46,019 gallons off a roof

Rainwater from a roof in Cleveland, TN

46,019gallons a year

That is a 1,500 sq ft asphalt roof under Cleveland, TN's normal 57.9 inches of rain, about 795 gallons for every inch that falls.

In Cleveland, 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 Cleveland 3.0 Ese station (3.3 mi away). Cleveland, TN ranks 12th wettest of the 65 cities covered in Tennessee.

Month by month in Cleveland

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan5.094,046
Feb5.154,093
Mar5.324,228
Apr5.184,117
May4.503,577
Jun5.064,022
Jul5.194,125
Aug4.113,26730
Sep4.613,664
Oct3.402,702118
Nov4.713,744
Dec5.584,435

Dec is the wettest month (5.58 in, 4,435 gal off the roof); Oct the driest (3.40 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 Cleveland

Best fit: one 55-gallon barrel, which delivers about 123 gallons to the garden in a normal year (82.9% 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 Cleveland's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal12344,531
110 gal12344,531
165 gal12344,531
275 gal12344,531
550 gal12344,531
1,000 gal12344,531
1,500 gal12344,531
2,500 gal12344,531
5,000 gal12344,531

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