Flash Flood — Garza, Texas

2010-07-04 · near Southland, Garza, Texas

Event narrative

The Garza County Sheriff's Office initially reported impacts from flash flooding shortly after 05:00 CST. At 05:03 CST, high water reportedly began to threaten a home in Southland and water was beginning to rapidly flow through many Post city streets. By 05:53 CST, reports indicated that a playa lake at the Post city pool had flooded and was overflowing with rapidly flowing water spilling over U.S. Highway 84 at a depth that was over the guard rails. By 06:02 CST, emergency officials reported widespread flooding of structures in Post, and that sewer was backing up into many homes and businesses. A door-to-door search was conducted to remove residents from flooded structures. The Lubbock Avalanche-Journal interviewed a woman who's car stalled in flood waters on her way to work. The woman then managed to walk to her place of business, a Post nursing home, where ankle-deep water filled the facility.

The failure of the Lake Stuart dam in eastern Lynn County resulted in a flood wave that travelled down the Double Mountain Fork of the Brazos River. Flash flooding along the river washed out a number of county roads in southwestern Garza County.

Farther downstream, flash flooding along the Double Mountain Fork upstream of Lake Alan Henry washed away support beams for two small oil lines. As a result, 165 barrels of crude oil spilled into the river and threatened Lake Alan Henry.

Despite these significant public impacts, no serious injuries were reported. State and county officials estimated the total economic loss in the county at $1.7 million. For the purposes of this report, these damages are differientiated here by flash flood and flood at $1.5 million and $200,000 respectively.

Wider weather episode

A plume of middle and upper tropospheric subtropical moisture streamed northward over west Texas during the first few days of July. Scattered showers and thunderstorms produced locally heavy rainfall each afternoon and evening starting on the 1st and persisting through the 3rd. Although little to no adverse public impacts were observed from the rains through the first three days of the month, the remnants of former Atlantic Hurricane Alex spread northward within the persistent tropical moisture plume and began to impact the west Texas South Plains during the late evening hours of the 3rd.

The remnants of Hurricane Alex brought the onset of widespread tropical rains to the South Plains region, with rainfall rates measured to exceed 4.00 inches per hour in some locations. The heaviest rainfall occurred along several convective bands that spanned southwest to northeast over the southern and central South Plains. Thus the most adverse impacts were experienced over portions of Terry, Lubbock, Lynn, and Garza Counties, where isolated locations received more than one foot of rain through the early morning hours of Independence Day.

The Fourth of July flash floods and floods brought extensive damages and economic loss to the area. Local and state officials estimated these losses to approach $16.5 million. The State of Texas declared several South Plains counties a Disaster Area, and federal assistence was requested. In spite of the dramatic agricultural and property damages, no serious injuries were reported.

Remnant flooding, generally near swollen playa lakes, persisted and resulted in prolonged closures of several roadways and highways until the 10th.

View location on OpenStreetMap → (33.3500, -101.5500)

Source: NOAA Storm Events Database, event_id 253710. Narrative written by the NWS forecast office that issued the report.