Engineers Save Residential Properties from Erosion

City uses retaining walls to stabilize banks after flooding

THE CHALLENGE

The City of Owensboro, Kentucky faced a huge problem: erosion from flooding caused the banks of Persimmon Ditch to collapse. Persimmon Ditch is one of the city's main drainage ditches that runs behind a residential neighborhood.

"There was a lot of subsidence that was compromising public utilities; backyards were starting to cave in and slump off into the stream," explained Jonathan Nieman, Design Engineer from CDP Engineers.

Engineers for the city needed a way to stabilize the banks of Persimmon Ditch before any further damage could be done. Given a 6-month time frame, the city was challenged with designing and installing a storm channel solution that would solve their problems for good.

THE SOLUTION

City engineers chose Redi-Rock gravity blocks to design five different walls in order to stabilize the banks along this ditch.

Redi-Rock is a precast, large block retaining wall system that uses the power of gravity to build tall retaining walls without the need for additional reinforcement in many applications. Redi-Rock blocks stack together like giant Lego blocks so they install quickly with minimal excavation required.

"How quickly it went together really helped our schedule with this project, considering the short time frame we had to get it complete," said Sean O'Bryan, Assistant City Engineer for the City of Owensboro.

As construction began, the design and install teams ran into several challenges including working in poor soil conditions with silty clay.

"We found that using the Redi-Rock block gravity wall was good because we were able to minimize our excavation. We didn't have to use grid, which would have required us to excavate further back into the bank and take land that wasn't within our easement," Nieman said.

Another challenge during construction was how to navigate around nearby utilities.

"One of the things that was interesting about this project was that there were existing manholes in the creek, and we had to change the wall alignment to accommodate a lot of utilities that were very close to the base of the wall," explained Clint Hines, Principal at JC Hines and Associates. "There were a lot of special details that had to be developed and it was nice to use the Redi-Rock system because there are so many specialized products."

THE OUTCOME

In total, over 7,000 square feet (650.3 square meters) of Redi-Rock in the Cobblestone texture was used to complete the project.

"Everybody here loved the look," said O'Bryan. "It's something that we've actually looked at using elsewhere, mainly because it is something that is pleasing to look at and it's going to hold up the banks from eroding away."

PROJECT DETAILS

Project: Persimmon Ditch #181 Customer: The City of Owensboro, Kentucky Engineer: CDP Engineers and JC Hines & Associates Manufacturer: Redi-Rock of Kentuckiana Installer: Redi-Rock of Kentuckiana Location: Owensboro, Kentucky Year Built: 2012