Over the past hundred years, Antelope Creek has flooded numerous times. A number of bridges over the creek are so small and low that as the creek rises, the bridges act as small dams, contributing to the flooding of nearby properties. A study issued by the city estimates that in a 100-year flood event, some areas would be under up to six –ft. of floodwater. In an analysis by the U.S. Army Corps of Engineers, it was determined that even an eight-year flood would result in widespread damage.
The goal of the Antelope Creek flood control project was to reduce approximately 80 percent of the estimated annual flood damage and to reduce and confine the 100-year flood plain within the channel banks. Though erosion was an additional concern, the increased surface runoff due to the impervious surfaces from city development made continual flooding the primary issue with Antelope Creek.
The Joint Antelope Valley Authority (JAVA) pushed for a ‘green’ solution, desiring a channel that would look natural, yet have the ability to withstand the events that would occur. Olsson Assoc. worked with the Corps of Engineers and Contech to provide a solution using ArmorFlex articulating block systems. Hard armor was chosen to withstand the shear velocities present in the canal.
The project is currently ongoing, with the creek treated to allow silt to settle. The ArmorFlex used is designed to allow the establishment of vegetation, producing some level of water treatment. However, the main goal was to move water. Approximately 100,000 square feet of ArmorFlex will be supplied for Phase III.