RoofRainYield

Alamogordo, NM rainwater: 8,449 gallons off a roof

Alamogordo, NM: gallons off the roof each year

8,449gallons a year

That is a 1,500 sq ft asphalt roof under Alamogordo, NM's normal 10.6 inches of rain, about 795 gallons for every inch that falls.

Alamogordo, NM has gaps between storms long enough to drain a single barrel. Around 275 gallons of storage catches most of what is worth catching.

Rainfall: NOAA 1991-2020 climate normals, the Alamogordo station (2.4 mi away). Alamogordo, NM ranks 14th wettest of the 19 cities covered in New Mexico.

Month by month in Alamogordo

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.68540
Feb0.59469
Mar0.33262
Apr0.27215509
May0.46366485
Jun0.56445473
Jul1.621,288340
Aug1.961,558298
Sep1.491,184357
Oct1.01803416
Nov0.56445
Dec1.10874

Aug is the wettest month (1.96 in, 1,558 gal off the roof); Apr the driest (0.27 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 Alamogordo

Best fit: a 275-gallon tote or tank, which delivers about 2,371 gallons to the garden in a normal year (82.4% of its need).

If you buy one, link barrels with a short hose at the base so they fill and drain together, and check the overflow points away from the house.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,1276,887
110 gal1,8446,170
165 gal2,1795,835
275 gal2,3715,642
550 gal2,6305,384
1,000 gal2,6305,384
1,500 gal2,6305,384
2,500 gal2,6305,384
5,000 gal2,6305,384

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 New Mexico?

Regulated through the State Engineer Office; no specific requirements exist for outdoor uses; indoor uses must meet quality standards; check county for local incentives

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