RoofRainYield

Los Lunas, NM rainwater: 7,336 gallons off a roof

Los Lunas, NM: gallons off the roof each year

7,336gallons a year

That is a 1,500 sq ft asphalt roof under Los Lunas, NM's normal 9.2 inches of rain, about 795 gallons for every inch that falls.

Los Lunas, 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 Los Lunas 3 Ssw station (2.8 mi away). Los Lunas, NM ranks 18th wettest of the 19 cities covered in New Mexico.

Month by month in Los Lunas

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.45358
Feb0.42334
Mar0.54429
Apr0.55437474
May0.49389481
Jun0.52413478
Jul1.551,232349
Aug1.531,216352
Sep1.15914399
Oct0.92731428
Nov0.57453
Dec0.54429

Jul is the wettest month (1.55 in, 1,232 gal off the roof); Feb the driest (0.42 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 Los Lunas

Best fit: a 275-gallon tote or tank, which delivers about 2,621 gallons to the garden in a normal year (88.6% of its need).

If you set one up, 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 gal1,1005,816
110 gal1,9504,967
165 gal2,3744,542
275 gal2,6214,295
550 gal2,7074,209
1,000 gal2,7074,209
1,500 gal2,7074,209
2,500 gal2,7074,209
5,000 gal2,7073,417

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