Charleston Harbor Post 45 Draft Integrated Feasibility Report/Environmental Impact Statement Executive Summary

Transcription

1 Charleston Harbor Post 45 Draft Integrated Feasibility Report/Environmental Impact Statement i

2 U.S. ARMY CORPS OF ENGINEERS NAVIGATION MISSION Provide safe, reliable, efficient, and environmentally sustainable waterborne transportation systems for movement of commerce, national security, and recreation. U.S. ARMY CORPS OF ENGINEERS ENVIRONMENTAL OPERATING PRINCIPLES Foster sustainability as a way of life throughout the organization. Proactively consider environmental consequences of all US Army Corps of Engineers (USACE) activities and act accordingly. Create mutually supporting economic and environmentally sustainable solutions. Continue to meet our corporate responsibility and accountability under the law for activities undertaken by the USACE, which may impact human and natural environment. Consider the environment in employing a risk management and systems approach throughout life cycles of projects and programs. Leverage scientific, economic, and social knowledge to understand the environmental context and effects of USACE actions in a collaborative manner. Employ an open, transparent process that respects views of individuals and groups interested in USACE activities. FOR INFORMATION CONTACT: Mr. Mark Messersmith, U.S. Army Corps of Engineers, Charleston District, 69A Hagood Avenue, Charleston, SC 29403, , or Chas-Post45-Comments@usace.army.mil ii

3 Charleston Harbor Post 45 Draft Integrated Feasibility Report/Environmental Impact Statement CHARLESTON HARBOR POST 45 June 2015 FINAL INTEGRATED FEASIBILITY REPORT AND ENVIRONMENTAL IMPACT STATEMENT RESPONSIBLE AGENCIES: The lead agency for the navigation study is the U.S. Army Corps of Engineers (USACE), Charleston District. The South Carolina State Ports Authority (SCSPA) is the non-federal sponsor. ABSTRACT: Charleston Harbor is located in a natural tidal estuary, formed by the confluence of the Cooper, Ashley, and Wando rivers. The study area encompasses the offshore entrance channel, offshore and landside confined dredged material disposal sites, inner harbor channels, and any extension of the water bodies and shorelines that could be impacted by proposed improvements. Alternative plans combined multiple structural and nonstructural measures to improve the safety and efficiency of the existing navigation system. Navigation concerns include three main types of problems: insufficient Federal channel depths, difficult currents, and restrictive channel widths and turning basins. The Recommended Plan (RP) is a Locally Preferred Plan (LPP). It proposes the following navigation improvements: Deepen the existing entrance channel from a project depth of -47 feet to -54 feet mean lower low water (MLLW) over the existing 800-foot bottom width, while reducing the existing stepped 1,000- foot width to 944 feet from an existing depth of -42 feet to a depth of -49 feet. Extend the entrance channel approximately three miles seaward from the existing location to a depth contour including a -54-foot MLLW project depth plus overdepths. Deepen the inner harbor from an existing project depth of -45 feet to -52 feet MLLW to the Wando Welch container facility on the Wando River and the new Navy Base Terminal on the Cooper River, and -48 feet MLLW for the reaches above that facility to the North Charleston container facility (over expanded bottom widths from 400 to 1,800 feet). Enlarge the existing turning basins to an 1800-foot diameter at the Wando Welch and new SCSPA terminals to accommodate Post Panamax Generation 2 and 3 container ships and widen selected reaches as shown in the : Reference Aid at the end of this section. Enlarge the North Charleston Terminal turning basin to a 1650-foot diameter for Post Panamax Generation 2 container ships. Place dredged material and raise dikes at the existing upland confined disposal facilities at Clouter Creek, Yellow House Creek, and/or Daniel Island; and for material dredged from the lower harbor, place at the Ocean Dredged Material Disposal Site (ODMDS) and expand. Place rock to create hardbottom habitat near the entrance channel as a least cost beneficial use of dredged material. The RP is economically justified. It would indirectly impact about 324 acres of wetlands through changes in salinity, which would require mitigation in the form of preservation of up to acres of wetlands. Approximately 29 acres of direct impacts to hardbottom areas within the footprint of the entrance channel require mitigation through creation of approximately 30 acres of hardbottom habitat. Construction of the RP would cause temporary increases in turbidity; however, these levels would not exceed permitted variance levels outside the mixing zone. Impacts to fish species may occur due to loss of habitat from potential salinity changes associated with deepening. iii

4 CHARLESTON HARBOR POST 45, CHARLESTON, SOUTH CAROLINA FINAL INTEGRATED FEASIBILITY REPORT AND ENVIRONMENTAL IMPACT STATEMENT EXECUTIVE SUMMARY The results of engineering, economic, environmental, and real estate investigations performed for this Feasibility Study (FS) are being used to determine if the Federal government should participate in submitting a report seeking authorization of potential navigation system improvements at Charleston Harbor, South Carolina. The South Carolina State Ports Authority (SCSPA) requested the study under Section 216 of the Flood Control Act of 1970 (Public Law ), which authorizes the review of completed projects in the interest of navigation and related purposes to determine the feasibility of further port deepening. DESCRIPTION OF REPORT This Final Integrated Feasibility Report and Environmental Impact Statement (IFR/EIS) documents the FS process and presents the results of investigations and analyses conducted to evaluate modifications to the existing Federal navigation system to improve its ability to efficiently serve the current and future vessel fleet and process the forecasted cargo volumes. It presents: (1) a survey of existing and future conditions; (2) an evaluation of related problems and opportunities; (3) development of potential alternatives; (4) a comparison of costs, benefits, adverse impacts, and feasibility of those alternatives; and (5) identification of a National Economic Development (NED) Plan and Recommended Plan (RP). PURPOSE AND NEED The cargo transportation industry continues its shift to increased use of standardized containers used for multimodal (marine, rail, and truck) freight transportation systems. Additionally, the marine vessel fleet is trending to larger, deeper-draft vessels, particularly for containerships. The Federal channels serving Charleston Harbor s major terminals are currently authorized to a depth of -45 feet mean lower low water (MLLW). The existing dimensions of those channels place constraints on deeper-drafting containerships, which result in reduced efficiency and increased costs. Specific problems warranting Federal consideration include navigation and safety considerations, engineering challenges, and concerns of those who live and work along or around the Federal navigation project. Navigation and safety considerations include three main problems: insufficient Federal channel depths, difficult currents, and restrictive channel widths and turning basins. Larger ships currently experience transportation delays due to insufficient Federal channel depths. To reach port terminals, these larger ships must either light load, experience delays while waiting for favorable tide conditions, or both. These approaches require the vessel operator to forego potential transportation cost savings available from the economies of scale associated with larger ships. Strong and unpredictable ebb tide crosscurrents at the confluence of the Wando and Cooper rivers make turns difficult in the channel reaches immediately north of the Ravenel Bridge. Restrictive channel widths also limit ship passage to one-way traffic in many reaches and larger container ships require expanded turning basins. iv

5 ALTERNATIVES AND RECOMMENDED PLAN Alternative plans combining multiple structural and nonstructural measures to improve the safety and efficiency of the navigation system were considered. The Reference Aid at the end of this summary provides key information and illustrates the general locations of the most important project features. To determine whether the Federal government should participate in implementing navigation improvements, the expected returns to the national economy (NED benefits) are calculated. NED benefits are generated by addressing inefficiencies in the existing transportation system to lower transportation costs. Net benefits are calculated by subtracting the total cost to construct and maintain the improvements over a 50-year study period from the total transportation cost savings that would be generated by the proposed improvements over that period. The NED Plan is the alternative that reasonably maximizes net NED benefits while remaining consistent with the Federal objective of protecting the nation s environment. Where two cost-effective plans produce similar net benefits, the less costly plan is identified as the NED plan, even though the level of outputs may be less. The NED Plan is normally recommended for implementation. However, if the non-federal sponsor prefers a more costly plan and is willing to pay the additional costs, a Locally Preferred Plan (LPP) can be recommended if the outputs are similar in kind, and equal to or greater than the outputs of the NED Plan. In this study, two cost-effective alternatives were developed that generated comparable net benefits. After careful consideration, the USACE identified the less costly alternative as the NED Plan. The RP, presented as the proposed plan is an LPP. It is more costly than the NED plan but generates more net benefits. It would deepen the inner harbor channels leading to the Wando Welch container facility and the new Navy Base Terminal from the existing -45 feet MLLW to -52 feet MLLW, and the channel from the new Navy Base Terminal to the North Charleston container facility from -45 feet MLLW to -48 feet MLLW. The entrance channel would be deepened from -47 feet MLLW to -54 feet MLLW. The NED Plan would deepen all the same segments 2 feet less than the RP, except for the reach between the New Navy Base Terminal to the North Charleston container facility which would be deepened from -45 feet MLLW to -48 feet MLLW. Along with the deepening, widening measures would be applied to accommodate the needs of the future containership fleet that is expected to serve Charleston Harbor. The Reference Aid at the end of this summary compares the existing channel dimensions with the proposed improvements, summarizes the economic benefits and costs associated with the RP and the tentatively identified NED Plan and illustrates the general locations of the proposed improvements. COSTS AND BENEFITS The USACE employed the traditional providers of traffic and fleet projections to study the Charleston Harbor project. Based on existing and projected future vessel traffic, vessel fleet mix, trade route allocations, and liner services currently associated with the Port of Charleston, two design vessels were selected. The vessel mix was allocated over time to provide benefit calculations using the HarborSym economic analysis model. The characteristics of the design vessels were used to develop channel dimension and alignment needs. Further refinement of the dimensions and alignment is expected through application of ship simulations prior to developing final designs. The dimensions of the two v

6 design vessels are described as follows: (1) a 1,100-foot length, approximately a 141-foot beam, and a 48-foot draft; and (2) a 1,200-foot length, 158-foot beam, and a 50-foot draft. These dimensions correspond with the range of vessels comprising Post Panamax Generation 2 and Generation 3 containership classes. The projected growth of containerized traffic allocated primarily between the time-modified mix of the two design vessels (without inducing traffic from other ports) has provided average annual net benefits of $80.9 million for the RP and $77.4 million for the NED Plan. While the benefit to cost ratio (BCR) of some shallower alternatives are higher, the RP maximized net benefits and maintained a robust BCR of The estimated project costs are $520.9 million and economic investment costs are estimated to be $580.6 million. The entire project is economically justified. Table 1 provides a summary of the Federal and non-federal costs and Table 2 provides the annualized benefits and costs for the RP. The benefits, almost exclusively attributable to container traffic, are achieved by transportation savings through the use of larger ships to transport the projected cargo volumes. ENVIRONMENTAL IMPACTS AND MITIGATION Public and Agency concerns were expressed throughout the study about the effects of the study alternatives on salinity and associated ecological changes to wetlands and fish habitat; water, air and sediment quality; shoreline erosion; cultural resources; and hardbottom habitat; among others. Numerical models and other analytical tools were used to predict and quantify the potential project related effects. The RP would indirectly impact about 324 acres of wetlands through increases in salinity, which would require mitigation in the form of preservation of about acres of wetlands. The USACE has determined that preservation of land within the Francis Marion National Forest best meets the compensatory mitigation requirements. The proposed preservation of ecologically significant parcels would provide important physical, chemical and biological functions for the Cooper River Basin and would contribute to the sustainability of the watershed by ensuring the functions of bottomland hardwood and emergent wetlands on these properties are sustained in perpetuity. The preservation parcels would also enhance lands already within the Francis Marion National Forest by functioning as a buffer to future development. About 30 acres of hardbottom habitat would be created using dredged material to compensate for direct impacts to about 29 acres of hardbottom habitat currently occurring within the channel and the indirect impacts to hardbottom habitats near the channel. The new hardbottom habitat would consist of two mitigation reefs (1 required, 1 additional) and six (totaling eight) similar new 33-acre reefs that will be constructed as a beneficial use of dredged material. Prior to construction, the locations of these reefs would be refined and coordinated with resource agencies. At the request of the SCDNR Artificial Reef Program, rock material will also be deposited at the 25-acre Charleston Nearshore Reef site as a beneficial use of dredged material. All proposed rock placement is part of the least cost disposal plan because all of the reef placement sites are closer to the dredging site than the alternative Ocean Dredged Material Disposal Site. vi

7 TABLE 1 FEDERAL AND NON-FEDERAL COSTS FEDERAL/NON-FEDERAL COST APPORTIONMENT Recommended Plan (Cost at 1 Oct 2014 Price Levels as of 13 Apr 2015 Benefits Provided 15 Apr 2015) Maximum Widening & Turning Basin Expansion Measures with 800-foot Entrance Channel with Wings COST SHARING FOR > 45 FEET CONSTRUCTION ITEM/GENERAL NAVIGATION FEATURES (GNF) PROJECT COST Recommended Plan (RP) FEDERAL based on NED cost NON-FED GNF Difference RP minus NED Dredging -- Mobilization and & Demobilization (included in segment costs) Entrance Channel to Wando (Segment 1) $390,720,000 $174,930,000 $215,790,000 Drum Island to Daniel Island Reach (Segment 2) $23,630,000 $10,685,000 $12,945,000 Daniel Island Bend to North Charleston Terminal (Segment 3) $30,690,000 $15,345,000 $15,345,000 Disposal Area Dike Improvements $16,780,000 $8,390,000 $8,390,000 Environmental Monitoring-9 Yrs (cultural hist. shoreline erosion) $5,310,000 $2,655,000 $2,655,000 Environmental Monitoring-9 Yrs (wetlands/hardbottom) $10,620,000 $5,310,000 $5,310,000 Real Estate, Admin (costs associated with mitigation) $37,500 $18,750 $18,750 Real Estate Land Payments NFS Acres Wetland Mitigation $2,995,000 $1,070,000 $1,925,000 Preconstruction, Engineering, Design, & Planning $5,600,000 $2,800,000 $2,800,000 Construction Management (S&I) $6,930,000 $3,140,000 $3,790,000 TOTAL GNF $493,313,000 $224,344,000 $268,969,000 SUBTOTAL PROJECT FIRST COSTS (rounded) $493,300,000 $224,300,000 $269,000,000 ADDITIONAL 10% OF (NED) GNF $0 -$44,870,000 $44,870,000 NON-FEDERAL SPONSOR S PAYMENT OVER 30 YEARS $0 -$44,870,000 $44,870,000 NON-FEDERAL LOCAL SERVICE FACILITIES (100% NON-FED) Berthing Area Dredging (Wando, New Navy Base, NC Terminals) $4,970,000 $0 $4,970,000 Port Bulkhead Construction (Wando Terminal) $22,000,000 $0 $22,000,000 TOTAL NON-FEDERAL LOCAL SERVICE FACILITIES $26,970,000 $0 $26,970,000 USCG AIDS TO NAVIGATION (100% FEDERAL) $620,000 $620,000 $0 PROJECT COSTS 52/48 Plan (rounded) 521,000, ,000, ,000,000 vii

8 TABLE 2 COSTS AND BENEFITS PROJECT COSTS $ PROJECT COSTS $521,000,000 INTEREST DURING CONSTRUCTION $59,800,000 ECONOMIC INVESTMENT $580,800,000 Average Annual Equivalent (AAEQ) COSTS Economic Investment $24,200,000 Increased O&M Dredging $3,740,000 Increased O&M for Navigation Aids $50,000 TOTAL AAEQ COSTS $28,000,000 BENEFITS (TRANSPORTATION COST SAVINGS) Origin to Destination Deepening $105,300,000 Channel Widening and Tidal Delay $3,600,000 TOTAL AAEQ BENEFITS $108,900,000 AAEQ NET BENEFITS $80,900,000 BENEFIT TO COST RATIO (at Federal Discount Rate FY14 of %) 3.89 Construction of the RP would cause temporary and minor adverse impacts to water quality in the areas near dredging activities. The predicted magnitude of project-induced dissolved oxygen reductions are small and would not significantly impact aquatic organisms or require mitigation to comply with state water quality standards. The USACE, Charleston District is committed to monitoring the impacts of the project and ensuring that they are similar to those predicted during the study. The RP would have no significant effect on any threatened and endangered species. Construction impacts would likely have temporary adverse affects on sea turtles and sturgeon species. However, no long term impacts of the RP would be expected for most threatened and endangered species and it would not likely adversely affect the Atlantic and shortnose sturgeon. Geophysical, bathymetric and diver investigations of three potential cultural resource targets revealed no culturally significant objects within the project footprint. Dredging in one channel reach in the lower harbor will be monitored by an archaeologist due to one anomaly nearby the channel. AREAS OF CONTROVERSY AND UNRESOLVED ISSUES Areas of Controversy: A number of issues were raised by agencies and the public, including salinityrelated impacts to wetlands, the associated mitigation and monitoring, impacts to hardbottom habitat, and water quality, and potential impacts to threatened and endangered species. Issues to be Resolved: The USACE, Charleston District will continue to coordinate the proposed action and the associated impacts identified above as well as any new issues that are identified during the review period with the USACE, South Atlantic Division and Headquarters, as well as the local sponsor, viii

9 state and Federal agencies, stakeholders, and concerned public. Several Preconstruction Engineering and Design (PED) phase commitments require additional coordination with resource agencies. They include: An analysis of potential beneficial use of dredged material projects in addition to the 8 hardbottom habitat reefs currently proposed A ship simulation analysis to determine areas where widening measures could be eliminated or reduced, where practicable Monitoring efforts, modeling and analyisis before during and after construction to validate the assumptions used in the analysis and verify that no unanticipated changes to wave, current, and sediment transport dynamics, or shoreline erosion resulted from the project A detailed evaluation of wetland mitigation using the Uniform Mitigation Assessment Method on the selected parcel proposed for mitigation based on the final project after all widening measures are defined An analysis of the benefits of constructing 2-3 new contraction dikes to reduce future maintenance dredging. AREAS OF RESIDUAL RISK The unresolved issues described above present minimal residual risks. The conservative assumptions used to replace data collection efforts during the study make it more likely that costs and impacts will be lower than those presented in the IFR/EIS. Any additional beneficial uses of dredged material would be implemented at the option of the USACE and the cost difference would likely be paid by the the entity requesting the use of the material. Ship simulation is more likely to present opportunities to reduce widening measures than increase them. Decreasing the size of one or more widening measures could significantly reduce both costs and the adverse environmental impacts and associated mitigation requirements. There is general agreement related to the project s overall lack of adverse impacts to waves, currents and erosion in Charleston Harbror. However, it is difficult to accurately predict effects at specific locations with a high degree of confidence. Based on this uncertainty and the presence of several significant natural and historic resource, the USACE agreed to monitor for unanticipated adverse impacts to significant natural and historical resources in Charleston Harbor. Monitoring could detect unanticipated adverse impacts but the likelihood is considered low. ix