RoofRainYield

Crossville, TN rainwater: 45,725 gallons off a roof

Crossville, TN: gallons off the roof each year

45,725gallons a year

That is a 1,500 sq ft asphalt roof under Crossville, TN's normal 57.5 inches of rain, about 795 gallons for every inch that falls.

In Crossville, 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 Crossville Mem Ap station (2.8 mi away). Crossville, TN ranks 13th wettest of the 65 cities covered in Tennessee.

Month by month in Crossville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan4.953,934
Feb5.134,077
Mar5.444,324
Apr5.474,348
May5.184,117
Jun4.933,918
Jul5.464,340
Aug3.612,86992
Sep4.143,29026
Oct3.142,496151
Nov4.743,767
Dec5.344,244

Apr is the wettest month (5.47 in, 4,348 gal off the roof); Oct the driest (3.14 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Which tank size is worth it in Crossville

Best fit: one 55-gallon barrel, which delivers about 214 gallons to the garden in a normal year (79.5% of its need).

If you buy one, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Crossville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal21444,086
110 gal21444,086
165 gal21444,086
275 gal21444,086
550 gal21444,086
1,000 gal21444,086
1,500 gal21444,086
2,500 gal21444,086
5,000 gal21444,086

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