Driver Safety During Roadway Flooding

Safe to Proceed: Roadway Flooding Solution

Author: Frank Gutierrez, Regional Sales Manager at High Sierra Electronics, Inc. for South Central/Southeast U.S.A. 


Flooding causes more deaths and property damage in the U.S. than any other severe weather related event¹. The reason that so many people drown during flooding is because few of them realize the incredible power of water. A mere six inches of fast-moving water can knock over an adult. It takes only two feet of rushing water to carry away most vehicles, which includes pick-up trucks and SUVs.


Texas is prone to extremely heavy rains and flooding with half of the world record rainfall rates (accumulations in 48 hour less). It also has the distinction of being the state with the most flood-related deaths in the past thirty-six years. Bexar County in Central Texas, about 190 miles west of Houston, is particularly vulnerable because storms stall along the Balcones escarpment. This region has earned the nickname “flash flood alley”. Due to this geography, floods are a natural hazard and a regular occurrence.

In order to better prepare residents, Bexar County officials implemented a High Water Detection System (HWDS) in 2007. The High Sierra Electronics, Inc. (HSE) system has evolved over the years and now includes more than 100 sites. It uses a combination of rainfall and water level gauges to monitor conditions at low points on the roadways. When water rises to a pre-determined unsafe level, the sensor(s) automatically trigger flashing beacons and/or barrier gates. The system is solar powered and works during power outages (i.e., extreme weather events). The system provides control even in remote locations and County officials can receive text or email alerts when the system is activated.

Bexar County Texas Macaway High Water Detection System (HWDS) by High Sierra Electronics, Inc.


Information from the HWDS feeds a Bexar County public web site known as HALT, High Water Alert Lifesaving Technology. The HALT system is a tool used to warn drivers when there is too much water over the roadway to help prevent a potential drowning disaster. The public is encouraged to visit!/main/map where a map displays current flood information and emergency road closures. More specific information can be obtained by clicking (highlighting an area) on the map or entering a location. Alerts via a Twitter feed are also available.

Likewise, the City of San Antonio (within Bexar County) has implemented their own program known as SAFE, San Antonio Flood Emergency. The City emphasizes being prepared, being informed, being safe. They utilize HSE’s HWDS in the same manner with flashing beacons and automatic barrier gates. In neighboring Comal County, HSE was awarded a contract in 2010 for a similar project involving the installation of more than thirty stations. Plans are currently underway in coordination with the City of New Orleans’ Office of Homeland Security and Emergency Preparedness (NOHSEP) to deploy 24 stations with flashing beacons in August 2018.


(1) NOAA National Centers for Environmental Information (NCEI) U.S. Billion-Dollar Weather and Climate Disasters (2018).



About High Sierra Electronics
High Sierra Electronics was founded in 1992 and is headquartered in Grass Valley, California, with additional offices in San Antonio and Fort Worth, TX, and Louisville, KY. High Sierra specializes in flood warning sensors, equipment, and transmitters for public and improved traffic safety. For more information visit