Orange County Coastal Storm Risk Management Project
The U.S. Army Corps of Engineer's (USACE) primary mission on the Orange County Coastal Storm Risk Management (CSRM) Project is to provide coastal storm surge protection and flood damage risk reduction for the residents and businesses within coastal hazard zones in Orange County.
This project will help Orange County be more resilient to future storm and flood events. While the new levee system will help reduce the risk of coastal surge flooding to its design elevation, no levee fully eliminates flood risk.
The main features authorized for the Orange County Project include:
- Approximately 15 miles of new levees.
- Approximately 10 miles of new concrete floodwalls and gates.
- Seven pump stations to mitigate interior flooding during surge events.
- Approximately 450 acres of marsh restored through a mitigation plan.
- Approximately 560 acres of forested wetlands preserved through a mitigation plan.
There is currently no comprehensive levee system in place in Orange County. This new proposed levee system aims to reduce flood risk from coastal storm surge. The new levee system, which will include multiple pump stations, will be designed to address compound flood risks due to compound flood risks that occur when storm surge interacts with precipitation.
The Orange County Project will be designed to not increase interior drainage impacts, which are impacts to residents, businesses, and infrastructure on the inside of the levee system. Interior drainage system improvements proposed for the project—along with adopting good floodplain management practices—will help reduce impacts from severe flooding. Additionally, the seven new pump stations will help but not totally alleviate severe flooding under all situations.
The Orange County Project needs non-federal sponsorship of the project, which requires a cost-share.
- The Orange County and Orange County Drainage District are the non-federal sponsors.
- Texas Legislature will create a new entity to serve as the future, local non-Federal sponsor for construction of this project. In the meantime, the Orange County Drainage District and Orange County are serving as the interim non-Federal sponsors for the design of the project.
- Galveston Coastal Services Joint Venture (GSC JV), a team comprised of Stantec and Jacobs, has been contracted to design and prepare the project for construction.
Project Status & Schedule
USACE is currently in the early stages of preconstruction engineering and design (PED) for the Orange County Project. The project team expects to complete PED by the end of 2022, followed by construction which will take approximately five years.
The final alignment of the new levees, floodwalls, and gates has not been determined yet. While there are preliminary lines drawn on maps to indicate where the levees may be constructed, the exact location of future levees, floodwalls, gates, and pump stations is still in the design phase and will be communicated as the project progresses.
During this PED phase, the project team is taking into consideration many factors such as engineering best practices, funding, impacts to residents and business owners, environmental impacts, and cost-effectiveness.
USACE has been working with the OCDD and Orange County to conduct surveys to inform the project design which includes gathering important data on the ground in Orange County about:
- Subsurface characteristics.
- Storm-surge modeling.
- Environmental surveys.
The project team will be coordinating proactively with property owners, business owners, and residents who may be impacted by construction. This includes contacting property owners to obtain rights of entry to obtain this data required for project design. This data will be used to determine engineering specifications for construction and develop the final alignment of the project.
Real estate acquisition has not begun at this time and is not expected until late 2021 or early 2022 at the earliest.
In general, the interior drainage features of the project will not worsen existing conditions. This means that the risk of flooding from a given design storm event will not be increased by the project.
In fact, when interior drainage channels are constructed and pump stations are operational, the interior drainage within the levee system (closed state) may reduce the water surface elevations within the bayous and ditches under certain circumstances.