Does rainwater harvesting even work here?
The high desert is dry, but the monsoon dumps water fast when it comes. Catching even part of it means gallons you didn't have to haul.
- A surprising amount runs off a roof in one storm — far more than people expect.
- Every gallon you catch is one you didn't drive to town for.
- In Arizona, harvesting rainwater is legal and actively encouraged.
How much you can actually catch
The formula is simple, and the number usually surprises people the first time they run it.
- Roughly 0.6 gallons come off every square foot of roof per inch of rain.
- A modest roof in a single good monsoon storm can fill a large tank.
- Run your own roof area against local rainfall to size your storage.
Setting up the catch
You're just guiding roof runoff into a tank, cleanly.
- Gutters route roof water to a downspout and into your tank.
- A first-flush diverter dumps the dirty initial runoff before clean water enters storage.
- Screen the inlet to keep leaves, grit, and bugs out.
Holding what you catch
Same rules as any stored water: keep it dark, screened, and overflow-safe.
- Size the tank to your roof and storms, not your hopes.
- Use opaque or shaded tanks to stop algae.
- Plumb an overflow that drains away from structures, and screen every opening against mosquitoes.
Garden first, drinking last
Most people use rainwater for everything except drinking, which keeps treatment simple.
- Garden, animals, and washing are easy, low-treatment uses.
- For potable use you need proper filtration and disinfection — don't skip it.
- Even non-potable catchment dramatically cuts how much water you haul.
Out near Concho or St. Johns? We'll bring it to your land.
Water, propane, groceries, gas cans, lumber, a forgotten part from town — Concho Dash runs errands and deliveries straight out to off-grid parcels in the area. No app, no membership. Text what you need.
See what Concho Dash hauls → Text or call · 480-201-7275Want the full water playbook?
The High Desert Survival Guide covers catchment, hauling, storage, and emergency water reserves together as one system.
Get the High Desert Survival Guide →