RoofRainYield

Youngsville, LA rainwater: 53,085 gallons off a roof

Rainwater from a roof in Youngsville, LA

53,085gallons a year

That is a 1,500 sq ft asphalt roof under Youngsville, LA's normal 66.8 inches of rain, about 795 gallons for every inch that falls.

Youngsville, 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 Lafayette 13 Se station (7.4 mi away). Youngsville, LA ranks 3rd wettest of the 35 cities covered in Louisiana.

Month by month in Youngsville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan5.634,475
Feb4.383,481
Mar3.933,124
Apr5.284,197
May5.454,332
Jun8.066,406
Jul6.565,214
Aug6.925,500
Sep5.854,650
Oct5.104,054
Nov4.463,545
Dec5.174,109

Jun is the wettest month (8.06 in, 6,406 gal off the roof); Mar the driest (3.93 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 Youngsville?

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

If you set one up, 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 gal051,930
110 gal051,930
165 gal051,930
275 gal051,930
550 gal051,930
1,000 gal051,930
1,500 gal051,930
2,500 gal051,930
5,000 gal051,930

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