Thursday, March 24, 2016

Outflow Gates

A twenty-six foot diameter tunnel was bored from the north side of San Antonio to miles south of the city to keep the San Antonio river from flooding the downtown area as it has done many times in years past. From the inlet to this outlet there is a five hundred foot drop. This insures water will flow rapidly through this tunnel. Luckily I've never here during flooding or even any water flow through this tunnel. 


  1. That is one amazing achievement.

  2. It took ten years to complete this flood protection project. It has saved the downtown twice from flooding, first in 1998 and again in 2002. The tunnel is three miles long under the heart of the city and has an outlet diameter of 35 feet. The wider channel of the San Antonio River can handle the water south of the city. San Antonio is the most flash flood prone area in the country.

  3. Great engineering fact. Must be a great spectacle when the river is overflooding here.