Flash Flood in Hays County, Texas

Thunderstorms produced heavy rain that caused flash flooding in Kyle and San Marcos. The majority of the flooding was along the Blanco and San Marcos Rivers. A massive floodwave came down the Blanco River from Wimberley. Huge amounts of debris came with the flood waters. Four people were trapped on a roof awaiting a helicopter rescue in Kyle. I-35 was closed in both directions in San Marcos when the Blanco River flooded and overtopped the interstate. Hwy 80 bridge was also overtopped with flood water just east of I-35. Highway 80 was closed with debris bumping into a bridge structure. Water flooded the Aspen Apartment complex and water was reported to be up to the top of car tires in the parking lot. The Hays County jail in San Marcos was evacuated due to flooding. Many homes along River Road were flooded as well as businesses along the I-35 frontage road as the San Marcos river started to backup into town. All along the Blanco River in Hays County 1515 structures were impacted with 321 houses destroyed and an additional 376 receiving Major damage according to assessments. It is estimated that there were 100 million dollars in insured losses for this flash flood.

An upper level shortwave trough moved around the longwave low over the Four Corners region. This upper distubance interacted with a surface boundary moving northward as a warm front from South Texas into a very moist airmass. This combination led to thunderstorms that produced heavy rain and isolated severe weather. A historic flash flood occurred on the Blanco River late Saturday night into Sunday. Hundreds of homes were destroyed along the river from the City of Blanco down into Wimberley and San Marcos. The flood wave continued downstream for days affecting residents and homes along the San Marcos and Guadalupe Rivers. Early estimates show damages in excess of 100 million dollars. Several people lost their lives due to flash flooding. A large tornado outbreak occurred this Saturday night producing numerous small brief tornadoes.