PROJECT ALERT NOTICE (NV) Monsoon-related high water in Las Vegas

Date: Mon, 26 Jul 2021 11:29:39 EDT

Summary: A short but intense thunderstorm caused localized flash flooding in Las Vegas.

An intense thunderstorm and associated microbursts in Las Vegas with rain totals from a trace to over 1 inch of precip in a 30 minute period impacted the Las Vegas Wash on July 25. Wind speeds ranging from 50-70 mph damaged power lines and downed trees. The Henderson NV field office is deploying two flood teams to make recession measurements, collect high-water marks, and update ratings. One gage had minor damage and will be repaired shortly. After the recession measurements are evaluated, indirect measurements will be planned at sites lacking rating definition. Peaks on the Las Vegas Wash were not unusually large, but this storm is notable because of the ongoing extreme to exceptional drought in Nevada.