Lake Pontchartrain Levee Protection
The Lake Pontchartrain and Vicinity (LPV) Foreshore Protection Works experienced erosion at the toe of the existing foreshore riprap dike. The Southeast Louisiana Flood Protection Authority-East (SLFPA-E) utilized the ACB mat Flexamat, furnished by Motz Enterprises, Inc., along with other products for erosion protection.
Prior to installing Flexamat, grass seed was spread over the prepared subgrade. It is important to seed the area before installation so the seed has intimate contact with the soil. Additionally, this keeps the seed from washing away prior to germination.
The Flexamat mats were continuous in length, from the top of the armor to the toe. The mats were cut to custom lengths of 37', the exact length of protection required. The mats included geogrid and underlayment extensions for overlapping adjacent mats to create a continuous armored system. At the toe of the dike, Flexamat transitioned to existing riprap. A mini excavator and backhoe were the only equipment needed to complete the installation. The 4-person crew completed the installation in less than 1-workday.
The installation was completed in mid April, 2020. The first of many named storms during the 2020 hurricane season to make landfall in Louisiana was Tropical Storm Cristobal in early June of 2020 that produced significant storm surge flooding. In August 2020, Hurricane Laura made landfall. Hurricane Laura is tied as the strongest hurricane on record to make landfall in the state of Louisiana. The effects across Louisiana were devastating. Nearly 10-foot high storm surge was recorded with Hurricane Laura. Next, Hurricane Delta was the record-tying fourth named storm of 2020 to make landfall in Louisiana in early October of 2020. Many residents were still traumatized due to the significant damage from Hurricane Laura just over one month earlier. Unfortunately, in late October 2020, a record-tying sixth hurricane of the year to make landfall in the United States stuck this part of Louisiana, Hurricane Zeta.
The extremely active 2020 hurricane season was followed in 2021 with Hurricane Ida. Hurricane Ida was a deadly and destructive Category 4 hurricane that became the second-most destructive hurricane to make landfall in the Louisiana on record, behind Hurricane Katrina in 2005. In terms of strength, Hurricane Ida tied Hurricane Laura and the 1856 Last Island Hurricane as the strongest on record to hit the state.
Throughout these record setting hurricanes and tropical storms, the Flexamat shoreline protection has held strong. Other products utilized by the Southeast Louisiana Flood Protection Authority-East (SLFPA-E) have failed and washed away. In the photo gallery and video included in this profile, are pictures from the initial installation in 2020 and follow-up pictures in 2021 through May of 2023. Three years post installation, vegetation has become well established within the Flexamat ACB system.