Storm & Flood Damage Recovery in Gallup, NM

The total is misleading because of how it arrives and what the ground does with it. Monsoon cells drop most of that in a few short violent bursts onto mesas and thin soil that absorb almost nothing, so runoff happens at close to the full rainfall rate. The water concentrates in arroyos and arrives at buildings within minutes. Annual totals describe how little rain falls; they say nothing about what happens to it.

It is a channel, and treating it as one is the correct posture. Rain over its catchment fills it within minutes with flow that moves debris and undercuts banks, and because it looks like a dry gully for most of the year people build, fence, and store near it. Anything downstream of recently burned or newly graded ground is at greater risk still, since those surfaces shed more and carry more with them.

Keep the sheet moving past it. On ground that absorbs nothing, water travels across the surface until something interrupts it, and a slab edge a few inches above grade is exactly that. A berm, a shallow diversion, or a raised entry that lets a moving sheet pass by does more than anything applied at the wall. Sealing the slab and wall joint from inside treats the symptom and rarely holds against moving water.