Houston Flood Recap

[jeff]

The following is a short recap of the flooding on June 19th in Houston (Harris County):

As of June 23rd at 200pm: 3254 homes have been reported with water damage ranging from 1" to 18"

561 apartment units were flooded mainly in the Pasadena, S Houston area.

Multiple jurisdicitions continue to asses the damage and the house counts will surely change over the next several days.

Hardest hit area was along the S 610 Loop eastward across S Houston into Pasadena where 8-12 inches of rain fell in a 4-6 hour period. This equates to a 50-100 yr rainfall event and some localized spots may have exceeded a 500 yr rainfall for such a short time period.

The following local bayous experienced house flooding and overbank conditions: lower Hunting, lower Greens, entire Halls, Vogel Creek, Berry Bayou, HCFCD lateral unit A120 (Beamer Ditch, Kirkmont area), Vince Bayou, Little Vince Bayou, Armand Bayou, Carpenters Bayou, HCFCD lateral P138 and P122.

Rainfall rates between 300am and 700am Monday morning averaged 6-9 inches over the lower end of Sims Bayou near I-45 and Broadway. Such intense rainfall rates resulted in extensive sheetflow (overland flow) flooding across a large portion of the region over S Houston, Pasadena. 2296 homes were flooded in the 610/MLK/Cullen area from internal drainage not being able to handle the 3-5 inch per hour rainfall. There are very few drainage systems in the entire world that can handle such rainfall rates.

Massive channel improvements on lower Sims Bayou prevented upwards of 4500 homes from flooding and the watershed was able to absorb upwards of 11.0 inches of rain in 4-6 hours. Improvements along White Oak Bayou prevented flooding in the Jersey Village area and reduced downstream flows below the Beltway by as much as 3-5 feet.