NOTE: A detailed description of each study that is being conducted by GPA is available at the SEG web site.

BEACH EROSION COMMITTEE

1. Beach Erosion Study

The goals of the study are as follows:

• Develop Numerical Models – Develop computer models to describe the waves and currents in the study area.
• Historical Analysis -- Qualitatively and (to the practical extent) quantitatively define the historical bathymetry and shoreline changes that have occurred in the study area. Include the development of the federal navigation project and the construction of the jetties at the mouth of the Savannah River. Qualitatively assess changes in mechanisms that control shoreline accretion/erosion: incident wave energy, currents, sediment supply, and shoreline hardening (e.g., seawalls, groin fields, etc.).
• Establish Existing Conditions – Use the computer models to describe the existing conditions that influence sediment transport in the area, including incident wave energy and currents. Use the modeling results and historic change analysis to develop a sediment budget (sand budget) for the study area.
• Determine Projected Deepening Impacts -- Use the computer models to determine effects to the local wave and current conditions caused by the proposed channel deepening. Utilizing the projected effects to the wave and current conditions, quantify the potential impact of the proposed channel deepening. Any effects of the proposed deepening on the nearshore and inlet sediment budget will also be identified."

STATUS (as of 22 March 2000): Approved and Funded

2. Evaluation of Coarse/Fine Sand Ratio

Also known as "Obtain Environmental Clearances for Beneficial Uses". The study would identify the coarse/fine material ratio for deposition of sediments excavated during construction of the Expansion Project in three different locations (On the shoreline; In nearshore areas; and Adjacent to existing sand dunes). This work would include evaluation of potential adverse impacts of various ratios and placement locations. Coordination with natural resource agencies would be included to obtain their preliminary concurrence in the final ratios.

STATUS (as of 21 April 2000): Approved. Task statement still being prepared, so not yet funded.

3. Additional Studies Under Consideration:

Comprehensive Benefit:Cost Ratio Study:

• The primary goal is to identify and quantify the benefits that could result from nearshore or beach placement of harbor sediments. A secondary goal is to link sediment placement from maintenance of the Federal Navigation Project with the needs for beach quality fill in the Federal Tybee Island Shore Protection Project.
• A portion of this study would consider the best use of sediments removed during maintenance of the entrance channel and is, therefore, outside the scope of the Expansion Project. However, this portion is of interest to the Committee.

STATUS (as of 1 May 2000): Committee recommendation at the May 2 meeting that GPA and Corps work together to jointly conduct a single study that would address beneficial uses for both the Expansion Project and the existing Navigation Project.

1. Committee made no recommendations for studies.

2. Committee recognizes that GPA will be conducting technical studies and evaluations outside the SEG that are of interest to this Committee

• Sediment quality geotechnical aspects and chemical testing of sediments at two sites)
• Evaluation of nearshore disposal
• Revalidate conclusions of Tier I DMMP once final design (depth) is identified

3. Additional Studies Under Consideration:

Beneficial use of Inner Harbor O&M Sediments. This study will likely be outside the Expansion Project, but is of interest to the Committee. The Committee believes that further investigation of this issue is warranted. The benefits of a large beneficial use program would include (1) extending the life of the existing CDFs, (2) postponing the need for additional CDFs – with their accompanying loss of wetlands, and (3) being a better steward of the natural resources available in the harbor.

1. Literature Review and Discussion with Regional Experts on Depth of Passage of Juvenile American Shad, Hickory Shad and Blueback Herring During Downstream Migration Through Savannah Harbor.
Purpose: Assist in determining if sufficient information exists to determine whether low dissolved oxygen in the harbor would affect these species as they migrate through the harbor. Follow-on field studies may be needed to evaluate potential project impacts if sufficient information does not presently exist on the depth at which these species occur in the harbor. The report will be distributed to and reviewed by the Committee to obtain their assessment of whether sufficient information exists or additional field studies are needed.

STATUS (as of 22 March 2000): Approved, funded and complete.

2. Temporal and Spatial Distribution of Estuarine-Dependent Species in the Savannah River Estuary.
Purpose: Develop a baseline characterization of fishery habitat use in the upper portion of the harbor. Identify and document the fishery habitat value of the various types of estuarine emergent wetlands.

STATUS (as of 21 April 2000): Approved. Will be funded.

3. Spawning Aggregations of Recreationally Important Sciaenid Species in Savannah Harbor.
Purpose: Identify the presence of spawning aggregations of Sciaenid species in this estuary, and document their location (baseline characterization).

STATUS (as of 21 April 2000): Approved. Will be funded.

4. Additional Studies Under Consideration:

None, other than what may be indicated by the findings of Study #1 (Literature Review and Discussion with Regional Experts).

1. The goal of the MTRG is to develop a calibrated and accepted hydrodynamic model for use in evaluating potential impacts of the Expansion Project. The Tier I model is being refined and calibrated by GPA/ATM, and will then be reviewed by the MTRG during the course of the Tier II activities. As technical experts, the MTRG would review the model’s performance and provide their technical opinions of the model’s ability to replicate hydrodynamic and water quality conditions in the harbor. The model would be presented to the SEG after the MTRG completes its review of the model’s performance. The group recommended the following field data collection efforts:

• Task SEGP311 Chloride study field data collection
• Task SEGP312 Dissolved oxygen & sedimentation field data collection
• Task SEGP313 Marsh salinity field data collection
• Task SEGP311A Bathymetric survey above I-95
• Task SEGP312A Vertical & lateral dissolved oxygen profiling
• The group recommended the following model development efforts:
• Task SEGCL1 Develop salinity to chloride correlation model
• Task SEGDO1 Develop dissolved oxygen model
• Task SEGDO2 Refine and verify hydrodynamic & salinity models

The group recommended the following field data collection effort to assist those who would evaluate the impacts of potential changes in water quality parameters in the upper harbor:

• Task SEGFM1 Marsh Vegetation Survey- Field Data Collection
• Task SEGP314 Shortnose sturgeon distribution field study

STATUS (as of 22 March 2000): All have been Approved and Funded

2. Data Review of Tidal Amplitude:

The study consists of a review of available historic information on tidal amplitude in the Savannah estuary over the last 15 years. The purpose is to attempt to identify any changes in tidal amplitude that occurred as a result of the following three major changes in the harbor: (1) cessation of operation of the Tidegate, (2) implementation of the 1993/1994 harbor deepening, and (3) the closure of New Cut.

STATUS (as of 22 March 2000): Under review by GPA.

3. Additional Studies Under Consideration:

None.

Tidal amplitude will be a component of the output of the hydrodynamic model. The potential effects of harbor deepening on tidal amplitude will be included in the Tier II EIS.

The MTRG will likely continue to meet during the application of the model to review ATM’s findings and conclusions on potential water quality changes resulting from various proposed harbor modifications.

The MTRG is also expected to provide guidance concerning the format of output from the hydrodynamic and dissolved oxygen models so that regulators can easily review the models and their projected changes in hydrodynamic and water quality parameters.

4. Items for SEG Consideration:

• The MTRG will assist natural resource agencies in the defining critical conditions under which the model should be run to evaluate potential project impacts. This assistance will center around environmental (meteorological and flow) conditions that would produce the largest dissolved oxygen deficit reasonably expected to occur in the harbor in the near future. However, additional critical conditions must be established by other organizations/regulators/stakeholders to ensure the model is applied under all conditions under which potential project impacts need to be evaluated.
• There are no plans to confirm that the projections of the calibrated and approved 3-dimensional hydrodynamic model were accurate if/when the Expansion Project is implemented (post-construction verification). Such a confirmation would require an additional sampling program to be implemented after construction of the deepening occurs.
• Once GPA completes its use of the calibrated and approved 3-dimensional hydrodynamic model for identification of potential project impacts, there is no mechanism to update the model or maintain it in a "ready-to-use" status to evaluate other potential harbor modifications. Recalibration of the model will likely be required – based on a post-construction sampling program – to allow the model to be useful for evaluation of potential impacts of future harbor changes. Any recalibration would have to be approved by natural resource agencies before the model’s projections could be used for future impact evaluation purposes.

1. Phase 1 Studies

A study was developed to start the evaluation of potential project impacts on striped bass habitat. Phase 1 consisted of several components. Some of the components were funded by GPA – as they were directly related to the Expansion Project, while other components were funded by the Corps/GADNR Section 1135 Study. The study components are as follows:

• Task 1. Velocity and depth transect data collection in Back River. Expansion Project. This information would assist GPA in refining the hydrodynamic model in the sensitive Back River area.
• Task 2. Collect and analyze historic boundary forcing data. Expansion Project. This effort would allow the model to be used to hindcast hydrodynamic conditions that had occurred in the Back River area in the 1950’s, before the striped bass population crashed.
• Task 3. Prepare model grids. Expansion Project. This work would prepare model grids that would be needed when the model is ready to be applied for impact evaluation purposes.
• Task 4. Run model scenarios and analyze output. Section 1135 Study. This work consists of running the 1997 version of the model to obtain a preliminary evaluation of the effects of several potential large-scale changes in Back River area.
• Task 5. Report Preparation. Section 1135 Study. This task consists of preparation of a report to document the work conducted by ATM and their findings.

STATUS (as of 22 March 2000): Approved and Funded

2. Assessment of spawning sites and reproductive status of striped bass, Morone Saxatilis, in the Savannah River.
This study consisted of the following two major tasks:

• Task 1: Sampling for striped bass eggs and larvae, gear detection thresholds, and sampling efficiency. The objectives were (1) Validate egg detection thresholds for standardized egg collection methods and calibrate efficiency with known abundances of gelan gum beads; and (2) Quantify spatial and temporal egg abundances in the Savannah River Estuary.

(a) Intended Results: Criteria to quantify effects upon striped bass eggs due to changes in salinity in the Savannah River Estuary.

(b) Deliverables:

(i) Index of abundance of eggs spawned in 2000.

(ii) Information on the drift patterns of eggs released at predetermined sites in the Estuary. (i.e. Gelan bead study).

(iii) Egg net calibration to be determined from release of gelan beads. Determine egg detection thresholds and how they differ in the front and Back River.

(c) Intended use in the EIS or mitigation plan

(i) Estimate of the percent or number of eggs which will be impacted by increased salinity in the harbor. This information to be based upon the egg drift patterns obtained using gelan beads.

(ii) Probability analysis of impacts to Egg Habitat necessary for successful egg survival and hatching. To be based on the current hydrodynamic modeling being conducted by ATM, similar to that contained in the Tier I EIS.

(iii) From egg net calibration studies, determine what "egg sample abundance" means in terms of eggs at large in the population.

• Task 2. Maturity scheduling and ultrasonic imaging of adult striped bass. The objectives were to establish a maturity schedule and fecundity estimate for female striped bass.

(a) Intended Results: Criteria to quantify the number of eggs released by various age or length groups of female striped bass in the Savannah River.

(b) Deliverables: When combined with a population estimate to be completed by GA DNR, an estimate of the number of spawning age striped bass in the estuary will be obtained.

(c) Intended use in the EIS or mitigation plan: An updated review of the population structure and the dynamics of the adult striped bass population. (Obtained from the current research and ongoing GA DNR work)

STATUS (as of 22 March 2000): Approved and Funded

2. Additional Studies Under Consideration:

No additional field studies are planned at this time.

The only possibility is a repeat of flow studies conducted by Dr. Davin at higher flow conditions. This study would provide information on the transport of striped bass eggs (location and rate) during conditions typically experienced during the spawning season.

The Committee will likely want to assist ATM by identifying model application runs that should be run for a thorough evaluation of potential project impacts to striped bass.

1. The group has made no recommendations for studies.

2. The group has identified items and concepts to be included in the update of the economic analysis. They are confident that all the identified items will be included.

1. USFWS Tidal Wetlands Study:

The U.S. Fish and Wildlife Service and ATM jointly developed a study proposal to evaluate wetlands in the upper portion of the estuary. The study consists of several components. Those components are listed below, along with a brief summary of the intent of that feature.

A. Field Studies:

• Continued vegetation monitoring. Monitor vegetation to establish a baseline (existing conditions) for the Vegetative Succession Model.
• Water level study. Monitor changes in water level at the root zone within each vegetative association. This effort will help understand how the water level changes at the root zone in response to changes in water levels in the adjacent river.
• Marsh topography survey. Survey the elevation of each of ten USFWS vegetation monitoring sites within the floodplain. This information will be combined with the water level study to develop a hydrologic relationship between water level changes at various vegetative root zones in response to changes in water levels in the adjacent river
• Sediment characterization/mapping (spatial synoptic analysis). Sample sediments within the marsh area and analyze their physical and chemical natures. Using this information, spatially characterize the tidally-influenced marsh sediment types. Develop a set of GIS layers to display this sediment characterization (spatial boundaries of marsh zones from fresh to subsaline conditions).
• Transplanting experiments. Transplant cores of various marsh vegetative species and their substrates to locations within the estuary that are subject to different salinity conditions. This procedure will help define the relationship between vegetative community types, marsh substrates, and salinity regimes.
• Continued salinity monitoring. Monitor salinity levels in the marsh over a continual period to identify seasonal and/or annual changes in the salinity dynamics in the marshes.
• Development of a salinity spatial synoptic. Conduct short term spatially-intense synoptic sampling (approximately 100 sites) to identify the spatial distribution of salinity across and along the length of the floodplain in the vicinity of the Refuge.
• Tree gap analysis. Part 1: Document the relationship between tree canopy species and the sapling/seedlings in the various regeneration layers. This analysis will distinguish how present hydrologic regimes compare to previous conditions under which the canopy trees were established. Part 2: Collect seeds from selected trees species in the floodplain. Conduct a greenhouse-based study to determine growth rates of the various tree seedlings under differing salinity levels.
• Vegetation change analysis. Analyze aerial photographs and satellite imagery to determine changes in vegetative signatures over time. The focus will be on the forested shrub/scrub swamp located in the transition between the tidal forested and tidal freshwater marsh.

B. Model Development:

• Vegetative succession model development. Develop a GIS-based model similar to that of Pearlstine (1980). The model will use spatial hydrologic parameters as input variables. The model will determine the type of vegetation expected to occur at each specific site within the potential wetland impact area. Its output will include the acreage of wetland vegetation species under a given set of hydrologic conditions.

STATUS (as of 21 April 2000): Approved. Will be funded.

2. USFWS Resource Utilization Study:

The U.S. Fish and Wildlife Service also developed a study proposal to evaluate the fish and wildlife use of the wetlands in the upper portion of the estuary. The study consists of two components. (1) Migratory Bird Study, and (2) Nekton Study. The first component would determine the spatial and temporal use of tidal swamp forests, fresh, intermediate, and brackish-marshes by migratory birds. The study would document the avian use of these four major tidal wetland vegetation types by fall and spring migrants, as well as selected over-wintering species. The second component, the Nekton Study, would determine the nektonic use of the various marsh types to identify what portion of the fish species occupy and use the marsh surface. This data would help identify the ecological nursery function these marsh types provide in support of both estuarine and freshwater fisheries.

STATUS (as of 21 April 2000): Approved. Will be funded.

1. ITEMS FROM THE MATRIX OF ISSUES FOR POSSSIBLE STUDY

A. Channel slope erosion

Is this a concern for potential increases in shoreline erosion?

Is this a concern for the portion of submerged river bottom that confines the navigation channel (channel sideslopes)?

Evaluation of potential impacts to both the navigation channel sideslopes and shoreline erosion will be addressed outside the SEG.

B. Fort Pulaski erosion

Is this a concern for potential increases in shoreline erosion?

Potential impacts to cultural and historic resources, such as Fort Pulaski, will be addressed outside the SEG.

C. Fort Pulaski impacts

Is this a concern for visual impacts?

Potential impacts to cultural and historic resources, such as Fort Pulaski, will be addressed outside the SEG.

D. Dissolved Oxygen / Fecal Coliform on Beaches

1) What is the potential project impact to fecal coliform levels on beaches?

The committee chairs are not aware of any likely adverse project effect on this item and, therefore, see no need for a study of this issue under the SEG.
Committee chairs recommend dropping "Fecal Coliform on Beaches" as an issue on the SEG matrix.

2) Dissolved oxygen on beaches is being addressed sufficiently in ongoing work. This issue will be covered through analysis of issue A.5:"Impacts on dissolved oxygen deficit caused by harbor deepening".

Committee chairs recommend dropping "Dissolved Oxygen on Beaches" as an issue on the SEG matrix.

E. Ballast water

GPA (Morgan Rees) has made a presentation to the SEG on this issue. He will present further information in the future.

F. Hurricane Impacts

2. ADDITIONAL THOUGHTS FOR CONSIDERATION

A. Multiple committees looking at the same issue.

The committees are generally looking at an issue from different perspectives.

The committee chairs see no existing or future problem with having multiple committees looking at the same issue.

B. Cultural resources.

GPA will be conducting studies and design work to implement the provisions contained in the Tier I FEIS. This work will be conducted outside the SEG.

All work will be coordinated with regulatory agencies, particularly the State Historic Preservation Officers

All work will be included in the Tier II EIS.

C. Post-construction monitoring of environmental effects.

The committee chairs believe this should be a part of the discussion of mitigation items.

D. Maintaining the hydrodynamic model

There is presently no mechanism or organization to update the model or maintain it in a "ready-to-use" status to evaluate other potential harbor modifications.

Recalibration of the model will likely be required – based on a post-construction sampling program – to allow the model to be useful for evaluation of potential impacts of future harbor changes.

E. Should there be a final SEG report on the Expansion Project?

The Operating Guidelines refers to this, stating that GPA will describe the SEG process in the Tier II EIS. Should there be a final report from the SEG on its conclusions about the adequacy of the Tier II studies, and/or the justification for the selected channel improvement and accompanying mitigation plan.

F. Should the SEG continue after completion of the Expansion Project?