201B Nov 28, 2018 Oral Abstracts
Habitats 09:15 AM - 10:30 AM

This group session will showcase six restoration projects from Louisiana to Florida and highlight a wide range of project designs addressing specific goals. Each of the presenters will pinpoint tips for optimizing their restoration design and briefly explain their process of developing the restoration design specific to the project site and its goals. Each project site has its own quirks that make it unique from other coastal areas and require various types of investigations to design the best restoration layout to fit that site. The task of designing a successful restoration project with best available science and as much certainty as possible is a challenge for engineers and project managers, but there are ways to overcome hurdles. This session will allow presenters to discuss what information (modeling, science, data) is essential in designing a restoration project vs. what would be nice to have and what lessons they have learned over the course of the project planning phase. Information from each of the presenters and their respective projects will provide the audience an overview of the engineering and design methodology and will provide lessons to be applied to future restoration projects. This group session will be complemented by the “Getting Projects Shovel Ready (The Good, The Bad, and Ugly)” session explaining how the restoration design was carried throughout permitting process.

Mon Louis Island Restoration
00:01 AM - 11:59 PM
The Mon Louis Island Restoration Project included construction of an approximate 1,540-ft. continuous rock dike breakwater and 4 acres of tidal marsh along the bay side of the northern tip of Mon Louis Island at the mouth of east Fowl River in Mobile County, Alabama. The project also included maintenance dredging of the Fowl River navigation channel. The constructed breakwater/marsh system provides protection for approximately 8 acres of pre-existing tidal marsh that were restored during a previous project. The project began with the construction of the temporary access channel and rubble mound breakwater. Hydraulic dredging was then conducted at a nearby off-shore disposal area to provide fill-material for marsh creation. Following completion of the marsh fill, the project was left to settle for several months, during which time, settlement monitoring was conducted. An additional topographic survey was performed on the marsh fill surface, when monitoring indicated that the majority of the marsh settlement had occurred. The post-settlement topographic survey was then utilized to develop the final marsh grading and planting plan. The final grading plan included excavation (in the fill area) to create a tidal creek, and the construction of a minimal earthen berm on the east and west sides of the marsh fill. The berm, which was constructed with material from the tidal creek excavation, was created to provide short-term protection of the marsh fill prior to establishment of the permanent vegetative cover.
Lessons learned in the post-design phase from a living shoreline along the southern shore of Lake Pontchartrain, La.
00:01 AM - 11:59 PM
The Pontchartrain Levee District, through funding from the Coastal Impact Assistance Program, funded the construction of approximately a mile of living shoreline. The permitting process was non-problematic and there were no major issues working with the US Army Corp of Engineers New Orleans District. During permitting meetings, openings between the breakwaters were requested in order to allow movement of fish on either side of the breakwaters. These were added to the design. Outside of differential sediment and erosion, there were no major issues during the permitting phase.
Pensacola Bay Living Shoreline - Project GreenShores Site II.
00:01 AM - 11:59 PM
The Pensacola Bay Living Shoreline (PBLS) project includes the creation of salt marsh habitat and low-crested breakwaters that serve as benthic habitat. Regulatory and permit requirements for this project exist at the federal and state levels. At the federal level, USACE required an Individual Permit Authorized under Section 404 of Clean Water Act, 33 CFR Part 323 and Section 10 of the Rivers and Harbors Act, 33 CFR Part 322. A United States Coast Guard permit for Private Aids to Navigation, 33 CFR Part 66 will be needed for any warning signs, buoys, or lights placed in the water. State level permits for construction, water quality, and coordination of potential cultural resources are also required through the FDEP, with concurrence from the Florida Department of Historic Resources (SHPO). The project team engaged with the permitting agencies early in the design process and took an active approach to anticipate permit requirements during data collection. The data collection plan included biological surveying to determine the presence of submerged aquatic vegetation and shorebird nesting areas, pursuant to USFWS and NMFS requirements under the Endangered Species Act. An extensive underwater cultural resource surveying program was conducted including dives at certain locations of interest. A chemical analysis of the proposed borrow and placement areas was performed. Several aspects of the design considered potential permitting requirements including the borrow area dredging limits, construction corridors, and breakwater layout to allow for movement of water and marine wildlife.
Salt Aire - Design & Construction of a Shoreline Restoration and Protection Project on Mobile Bay
00:01 AM - 11:59 PM
The Salt Aire Shoreline Restoration project lies within Mobile County, adjacent to Goat Island, and the opening of the Fowl River into Mobile Bay. Over many years of exposure to unencumbered waves from Mobile Bay, the existing marsh has eroded approximately 300' over the past 20 years, particularly along the northern extent, where weaker soils are present. In addition, once present, healthy oyster reefs have been decimated by over-harvesting. To mitigate these effects, the project design consists of 1) restoration of approximately one mile of shoreline through creation of 30 acres of intertidal marsh and vegetative plantings, 2) shore parallel wave attenuation structures consisting of overlapping, intertidal breakwaters that allow for interlocking, stackable units, composed of concrete specially-designed to encourage oyster colonization and growth to facilitate reef development, and 3) shore-parallel and perpendicular structures placed around the exposed side of Goat Island and as containment at boundaries. To evaluate existing processes and develop proposed solutions, analyses utilized Delft3D models of both Future -Without-Project (FWOP) and Future-With-Project (FWP) scenarios. The simulation of hydrodynamics, wind-driven wave processes, and sediment transport reveal the effects of constructing the project on such properties on wave energy and sedimentation rates over a 50-year design life. Other aspects of the design include multi-lift dredged fill placements composed of spatially-varied lift-heights, and tidal creek networks. Progressing from the design process into bidding and construction, offers several lessons in the development of a multi-faceted living shoreline project.
Design of a Long-Term Monitoring Program for a Living Shoreline Project in Hancock County, MS
00:01 AM - 11:59 PM
The 29,909-acre Hancock County Marsh complex is one of the largest in Mississippi and is part of the Pearl River estuary. The Hancock County Marsh Living Shoreline Project was developed with two main restoration goals: 1) build living breakwaters for shoreline protection from wave erosion and support secondary productivity; and 2) create subtidal reefs to support secondary productivity. The project includes 5.9 miles of living breakwater, 46 acres of subtidal reef, and 46 acres of marsh. The project design was a result of detailed geotechnical and hydrodynamic analyses. In 2017, the subtidal reef and first 2-mile section of the living breakwater were constructed. Project performance monitoring began at the completion of construction and will continue for seven years. Construction of the remaining 4 miles of breakwater was completed in fall 2018 and the first year of monitoring will begin in 2019. The long-term monitoring program is used to establish trends towards the restoration goals. The project performance monitoring was designed to determine if the restoration goals and project objectives are being met. The monitoring components of the living breakwater include: 1) annual biological monitoring; 2) elevation and shoreline surveys; 3) annual aerial photography; and 4) annual structural integrity monitoring. The monitoring components of the subtidal reef include: 1) annual biological monitoring; and 2) subtidal reef height, elevation, and area surveys. Each monitoring component was developed to inform adaptive management strategies or corrective action decisions if the long-term trends suggest the restorations goals will not be met.
Shoreline Restoration and Habitat Longevity: The Lightning Point Living Shoreline Project
00:01 AM - 11:59 PM
The Nature Conservancy is investing in a 1.5-mile long living shoreline project that combines breakwaters, marsh creation, managed access, and public amenities in Bayou La Batre, AL. The Lightning Point shoreline has been significantly eroded over the 20th century, experiencing high episodic retreat from storm impacts (most recently by Hurricane Nate) that diminishes available wetland habitat. As large investments are made in this and other living shoreline projects, increasing project longevity in the face of sea level rise and storm volatility has become an important factor to consider in site design and long-term maintenance. Design features for the Lightning Point Restoration include 28 acres of marsh restoration with material from a nearby borrow area and previous dredge disposal site. Additionally, living shoreline concepts are implemented including breakwaters to reduce the high erosion rates experienced at the site, extending the life of the restored habitats. Functional tidal creeks are included between the breakwaters and the existing shoreline mimicking the natural tidal marshes in the area. Ecological design aspects of the project consider a diversity of habitat types for subtidal, intertidal, and higher scrub-shrub zones. In addition, existing beach features are preserved to prioritize establishment of locally threatened species and support community use. Resiliency and sustainability concepts were integrated early in the design phase for all project features. Robust shoreline protection, thoughtful fill and tidal creek design, and green public access features all ensure that the restored coastal habitats and revitalized waterfront continue to thrive in an uncertain future.

The Nature Conservancy
Moffatt & Nichol
Anchor QEA
HDR Engineering, Inc.
Moffatt & Nichol
Neel Schaffer
Thompson Engineering


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