Posted: Wed, 23 Feb 2011 12:00 AM - 13,474 Readers

By: Shelton Green

A civil engineer with the City of Austin’s Watershed Protection Department thinks he may have solved the mystery regarding the source of tons of sediment that have built up in portions of Bull Creek and Lake Austin.
In late January, KVUE interviewed Allen Bailey, a resident on the Lake Austin portion of Bull Creek near 2222 and 360.
 
Bailey spent $2,000 to move piles of sand from around his boat dock so he could access it, and so, too, did his neighbors and the neighborhood association.
 
The piles of sand dunes were more visible in late January after the City of Austin lowered Lake Austin to kill off some of the unwanted vegetation.
 
Bailey maintains that the sediment build up was from piles of dirt about half a mile upstream near a bridge building project of the Texas Department of Transportation.
 
“I would challenge any engineer to sample the debris on that island and compare it to the site on 2222 and 360 and tell me it's not the same stuff,” Bailey said to KVUE on Tuesday.
 
However Mike Kelly, a civil engineer with the city, went to the area upstream and downstream where he took soil samples trying to solve the puzzle. Kelly says his findings lead him to believe that the sediment build up in the water is a natural occurrence brought in by Tropical Storm Hermine in September 2010.
 
“The storm caused it. It was not the construction site. The fact that you saw so much sand and gravel deposited can only point to the fact that a huge land mass that stored up this kind of material was responsible for it. One small construction site would never be able to produce that amount of sediment,” concluded Kelly.
 
TxDOT told KVUE that the agency spent $300,000 to remove bridge construction debris from the boat dock of a local fire station, which they believe was carried there by Hermine flood waters.
 
According to the city, homeowners impacted by the sediment are on their own when it comes to paying for the removal of debris.  However, the city suggests checking with them to get a permit before doing so.