Flash flood cleanup after Las Vegas monsoon storms

Flash flood cleanup in Las Vegas is a monsoon job, because the National Weather Service says July and August storms send flash floods down normally dry washes and into low lying areas.

Muddy floodwater rushing past an orange railing and under a raised hotel building — FIG. 01Flamingo Wash in flood at the Imperial Palace, Las Vegas, September 1984. US Army Corps of Engineers slide.

How a flash flood reaches a house here

The National Weather Service describes Las Vegas monsoon storms that form in the mountains around the valley and then move into it. The flash floods they cause often sweep down normally dry washes or pour into low lying areas. The NWS also notes that caliche is almost impervious, so when rain falls in the valley almost all of it runs off.

On July 8, 1999, most of the rain fell in 90 minutes, between 10:30 am and noon, and the NWS records widespread street flooding and record flows in normally dry washes. Two people died, one of them caught in Flamingo Wash.

Cleanup is not the same as drying

Flood water carries silt and whatever it crossed on the way. Ready.gov says floodwater can be contaminated. So the order is extraction, mud out, sorting, cleaning and treating hard surfaces, then drying. Carpet, pad, insulation and the bottom of drywall that sat in flood water are usually removed rather than dried.

The insurance line to know first

The Nevada Division of Insurance says flood damage is not covered under standard homeowners, commercial and renters policies. A flood policy through the NFIP or a private company covers it, and there is typically a 30 day wait before a new policy takes effect. We document the damage either way. Our insurance guide lays out the difference.

The first hour

Clock	Action	Why
0 min	Get people out of the water	Do not walk or drive through moving water. Ready.gov says six inches of moving water can knock you down and one foot can sweep a car away.
2 min	Stop the source if you safely can	For a pipe, close the main shutoff. LVVWD says it is usually in the front yard near the sewer riser cap, in the garage or at the home's manifold.
5 min	Keep away from wet power	Ready.gov says not to touch electrical equipment that is wet or while you stand in water. Leave the breaker panel alone if the floor around it is wet.
10 min	Call or text (702) 602-9420	Tell us where the water came from, which rooms are wet and whether it came in from outside. That decides the crew and the gear.
15 min	Photograph everything before it moves	Wide shots of each room, close shots of the water line on walls, and the source. Your insurer will ask for these.
30 min	Lift and separate	Move rugs, boxes and furniture off wet floors. Put foil or wood blocks under furniture legs that must stay.
45 min	Treat flood water as dirty	Floodwater can be contaminated, per Ready.gov. Wear gloves and boots. Keep children and pets out.
60 min	Start the 48 hour clock	EPA says to dry water damaged areas and items within 24 to 48 hours to prevent mold growth. Extraction and drying should start inside that window.

Table. The first hour, from Ready.gov, EPA and LVVWD guidance.

Local numbers behind this page

Measure	Value	Source
July 8, 1999 storm, main rain window	90 min	National Weather Service
Days with 0.50 in of rain or more	2.3	NOAA NCEI 1991 to 2020 annual normals
August rain normal	0.22 in	NOAA NCEI 1991 to 2020 monthly normals
NFIP building limit, homeowners	$250,000	FloodSmart by FEMA
New flood policy wait	30 days	FloodSmart by FEMA
Regional Flood Control District created	1986	FEMA case study

Table. Each value links to its source.

Flood Cleanup questions

When do flash floods happen in Las Vegas?

The National Weather Service says monsoon thunderstorms typically come in July and August and the monsoon wanes by September.

Why does so little rain cause floods here?

The NWS notes caliche is almost impervious, so almost all rain that falls in the valley runs off instead of soaking in.

Is flood water dangerous to clean up?

Ready.gov says floodwater can be contaminated and may hide debris. It advises heavy gloves, protective clothing and boots during cleanup.

Does homeowners insurance pay for flash flood damage?

The Nevada Division of Insurance says standard homeowners policies do not cover flood damage. Flood coverage comes from an NFIP or private flood policy.

Can carpet be saved after a flash flood?

Carpet and pad that sat in flood water from outside are usually removed. Hard surfaces get cleaned, treated and dried.

When can I go back into the house?

Ready.gov says to return home only when authorities say it is safe.

How fast should cleanup start?

EPA says to dry water damaged areas within 24 to 48 hours to prevent mold growth, so mud out and extraction should start right away.

Do you remove mud from garages and yards?

We clear mud and silt from inside the home and attached garage as part of cleanup. Tell us what you see when you call so the crew brings the right tools.

What was the July 1999 flood?

The NWS describes a flash flood on July 8, 1999 when most of the rain fell in 90 minutes. It caused record flows in normally dry washes and two deaths.

How do I start a flood cleanup?

Call or text (702) 602-9420 with your street and a photo of the water line on the wall.