RoofRainYield

Central, LA rainwater: 52,473 gallons off a roof

How much rain a roof in Central, LA collects

52,473gallons a year

That is a 1,500 sq ft asphalt roof under Central, LA's normal 66.0 inches of rain, about 795 gallons for every inch that falls.

Central, LA gets enough rain in the growing season that a 200 sq ft garden rarely needs topping up, so a tank here is about saving the occasional dry spell, not a summer of watering.

Rainfall: NOAA 1991-2020 climate normals, the Baton Rouge Cntrl station (0.1 mi away). Central, LA ranks 6th wettest of the 35 cities covered in Louisiana.

Month by month in Central

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan6.865,452
Feb4.993,966
Mar4.873,871
Apr5.124,069
May4.923,910
Jun7.215,731
Jul5.404,292
Aug6.825,421
Sep4.893,887
Oct5.044,006
Nov4.193,330
Dec5.714,538

Jun is the wettest month (7.21 in, 5,731 gal off the roof); Nov the driest (4.19 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 Central?

Best fit: a 5,000-gallon cistern, which delivers about 0 gallons to the garden in a normal year.

Before you buy, a single 55-gallon barrel is plenty here; spend the money on a first-flush diverter and a screen rather than more storage.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal051,288
110 gal051,288
165 gal051,288
275 gal051,288
550 gal051,288
1,000 gal051,288
1,500 gal051,288
2,500 gal051,288
5,000 gal051,288

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 Louisiana?

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