Upgrade of Great Northern Detention Pond in the Works

Stephanie Lott
Public Information Specialist Senior
City of Austin

The City of Austin is planning to upgrade the detention pond at 6900 Great Northern Boulevard to improve the safety of the structure as required by state law. This pond controls flood waters that flow into Shoal Creek during severe storms, and it reduces the risk of flooding for many homes along the creek in the Allandale Neighborhood.

The embankment of the pond is high enough to be a dam according to state criteria and is periodically inspected by the City of Austin and the State of Texas. Although both have found the dam to be in good condition, it does not currently meet the state’s dam safety criteria. This project will upgrade the dam to state standards so that the dam continues to provide flooding protection. There are two major components to the upgrade:

* The safety of the structure will be enhanced in the event the dam is overtopped during an especially severe storm. A short wall will partially encircle the pond. It will direct any overflow over a concrete-lined spillway, so that the overflow will not weaken the structure of the dam.

* Unfortunately, many trees need to be removed, including all the trees and brush on the embankment itself. We have limited the tree removal as much as possible, but it is necessary to ensure the dam remains in good condition. The root systems of trees and brush tend to weaken dams and decrease their ability to resist the force of flood waters.

We know this is an area that many Allandale residents enjoy.  However, access to the area may be limited to the existing foot path for several months during construction. All are welcome to use the site once again after the upgrade is complete. 

For more information about this project, please come to a presentation for the Allandale Neighborhood Association at 7 p.m. on February 4, 2008, at the Northwest Recreation Center, located at 2913 Northland Drive.  During the meeting, we will give an overview of the project and ask for input on some aesthetic considerations.