Intracoastal Consultants, LLC (Intracoastal) was recently awarded the Belair Ponds – North and South Project from St. Tammany Parish Government. This area north of I-12 along Bayou Liberty has experienced flooding during several storm events causing repetitive flooding of structures. The Belair Ponds project was conceptually sized as two (2) ponds totaling nearly 200-acre in 2014 through an independent water quality study. The project includes developing the concept designs further by preparing a detailed two-dimensional (2D) Hydrologic and Hydraulic (H&H) model of the Liberty Bayou – Bayou Bonfouca HUC 12 watershed (±27,000 acres).

As a part of Intracoastal’s initial task, a Data Gap Analysis was performed to guide the Model Approach and develop the Design Criteria for the 2D H&H model. Intracoastal reviewed previous models prepared by St. Tammany Parish as well as the Louisiana Watershed Initiative’s (LWI) Region 7 model. The model approach developed will utilize the LWI model and clip it to the two HUC 12 watersheds within our focus area to build our detailed model for assessing the benefits of a regional detention pond. This approach saves the parish both time and money by reducing the level of effort required to collect data within the watershed and for developing the 2D H&H model. As an additional cost savings on construction, Intracoastal has proposed to evaluate connecting a series of borrow pits created from the I-12 construction to reduce the size of the proposed ponds along Liberty Bayou.

Upon approval of the Model Approach and Design Criteria, Intracoastal will prepare the 2D numerical model through HEC-HMS and HEC-RAS. The model will include include site specific data collected for the project to update the LWI model geometry and for sizing the pond, inlet channel, and outfall structure. Intracoastal will also be responsible for preparing construction plans, specifications, and cost estimates for the project.