Keansburg, East Keansburg and Laurence Harbor, New
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/ 1 171749 RARITAN BAY AND SANDY HOOK BAY, NEW JERSEY FEASIBILITY REPORT FOR HURRICANE AND STORM DAMAGE REDUCTION Keansburg, East Keansburg, and Laurence Harbor, New Jersey Draft Reevaluation Report Beach Fill Renourishment (Section 506 of WRDA 1996) Volume 2: Draft Environmental Assessment and Environmental Appendices |"C3"1 US Army Corps of Engineers New Jersey Department of Environmental Protection New York District November 2007 RARITAN BAY AND SANDY HOOK BAY HURRICANE AND STORM DAMAGE REDUCTION STUDY KEANSBURG, EAST KEANSBURG, AND LAURENCE HARBOR, NEW JERSEY DRAFT ENVIRONMENTAL ASSESSMENT Laurence Harbor , Project Area j NOVEMBER 2007 Prepared by: U.S. Army Corps of Engineers New York District 26 Federal Plaza New York, New York 10278-0090 DRAFT ENVIRONMENTAL ASSESSMENT RARITAN BAY AND SANDY HOOK BAY HURRICANE AND STORM DAMAGE REDUCTION STUDY KEANSBURG, EAST KEANSBURG, AND LAURENCE HARBOR, NEW JERSEY November 2007 Prepared By: U.S. Army Corps of Engineers New York District 26 Federal Plaza New York, NY 10278-0090 EXECUTIVE SUMMARY Raritan Bay and Sandy Hook Bay Hurricane and Storm Damage Reduction Study Keansburg, East Keansburg, and Laurence Harbor, New Jersey The U.S. Army Corps of Engineers (USACE), New York District (District), is currently evaluating the feasibility to provide beach renourishment to restore a previously authorized and constructed shore and hurricane protection to residential, commercial, and recreational resources in the Borough of Keansburg and the East Keansburg community of Middletown Township, Monmouth County, and the Laurence Harbor area of Old Bridge Township, Middlesex County, New Jersey (Study Area). Hurricanes, northeasters,, and extratropical storms have historically damaged homes, roads, commercial structures, shorefronts, beaches, and dunes throughout the Raritan Bay and Sandy Hook Bay (RBSHB) shore area. Erosion of the previously designed and constructed beach (both long-term erosion and periodic storm-induced erosion) and the lack of long-term shore protection measures such as periodic beach renourishments have resulted in the deterioration of the widths of beachfronts in the Study Area. Consequently, there has been a reduction in the capability of Project Area beaches to provide long-term protection to development from hurricanes and severe storms such as northeasters. In addition, the threat of future storms in this area of reduced beach widths poses a danger.to residents. The District has conducted this Draft Environmental Assessment (EA), according to the requirements of the National Environmental Policy Act (NEPA), in order to evaluate the potential impacts associated with the restoration of the previously constructed beach .berm, and renourishment of the beach area on a periodic basis to reduce the threat of potential damages to private, commercial, and public properties caused by future hurricanes and severe storms. Impacts from utilizing sand from the borrow area have been previously covered in a generic Environmental Impact Statement (EIS) on the borrow.site (USACE 1989; USACE 1995). The Keansburg, East Keansburg, and Laurence Harbor, New Jersey Beach Erosion Control and Hurricane Protection Study, was originally authorized for construction as part of the RBSHB Project, New Jersey, in the Flood Control Act of October 23, 1962, in accordance with House Document Number 464, 87th Congress, Second Session. The authorized project provided for construction of shore protection in various sections of the shoreline along RBSHB, including Keansburg, East Keansburg, and Laurence Harbor. However, while the project included construction activities for these areas, it did not provide for Federal participation , in follow-up protection activities such as periodic beach renourishments. Federal participation in construction in the Study Area terminated upon the completion of the Keansburg portion in 1973. Continued erosion of the shoreline has resulted in narrowed beachfront areas and a reduction in the protective capability of the beaches. Accordingly, the New Jersey Department of Environmental Protection (NJDEP) requested a re-evaluation of the need to provide beach erosion and storm damage protection at the Study Area. Consequently, pursuant to the 1976 HiN^Iilll RARITAN BAY AND SANDY HOOK BAY HURRICANE AND STORM DAMAGE REDUCTION STUDY : . KEANSBURG, EAST KEANSBURG, AND LAURENCE HARBOR, NEW JERSEY November 2007 ES-i Draft Environmental Assessment Water Resource Development Act (WRDA) Section 156, the 1986 WRDA Section 934, and the 1996 WRDA Section 506, the USACE was reauthorized to evaluate the feasibility and interest of continuing Federal participation/investment in periodic renourishment of the previously designed and constructed beach berms in the Project Area. This involvement would extend for a period of. up to 50 years from the initiation of construction of the original project beaches, or to year 2018 for Keansburg and East Keansburg, and to year 2015 for Laurence Harbor. The selected plan for the Keansburg and East Keansburg area provides for restored renourishment of the original storm damage reduction features of the authorized project (25-foot minimum dune width at +15.8 ft National Geodetic Vertical Datum [NGVD] elevation and 80 ft berm width at +11.8 ft NGVD elevation) through 2018, which covers two (at five years apart) renourishment operations (2009 and 2014) for the 14,400 feet (ft) of shoreline at Keansburg and East Keansburg. This renourishment plan restores the function of the constructed line of . protection; comprised of levees and a dune section^ and while periodic renourishment is required to protect the dune and prevent tidal inundation, this plan yields the maximum net benefits over cost in accordance with USACE budgetary policy. Material for construction arid periodic renourishrhent for the project at Keansburg and East Keansburg will be obtained from a previously authorized and permitted offshore source known as the Sea Bright Borrow Area. The first construction quantity is approximately 2,103,000 cubic yards (cy). The second renourishment quantity is approximately 471,000 cy. For purposes of economic analysis for this report, project economics and cost for consistency were both developed at the October 2006 price levels. The estimated total project cost, which includes the cost to construct the first renourishment operation in 2009 and the second in 2014 at Keansburg and East Keansburg is $39,825,000 ($25,886,000 Federal / $13,939,000 non- Federal). The estimated cost to construct the first renourishment operation is $32,464,000 ($21,102,000 Federal / $11,3,62,000 non-Federal): The estimated cost to construct the second renourishment operations is $7,361,000 ($4,785,000 Federal / $2,576,000 non-Federal). The estimated annual cost including interest, amortization and future renourishment is $3,770,000 with total annual benefits of $8,528,000 (including $4,758,000 in net benefits). The benefit to cost ratio for the Keansburg to East Keansburg area is 2.3 to 1. The selected plan for the Laurence Harbor area provides for restored renourishment of the western section of the original storm damage reduction features of the authorized project (25- foot minimum dune width at +16.8 ft NGVD elevation) through 2015, which covers the first renourishment operation in 2010 and a second renourishment operation in 2015, for the 3,000 feet of shoreline at Laurence Harbor. This renourishment plan restores the function of the constructed line of protection of a dune section and while periodic renourishment is required to protect the dune and prevent tidal inundation and wave attack, this plan yields the maximum nef benefits over cost in accordance with USACE budgetary policy. The selected plan for Laurence Harbor is not economically justified and any action in Laurence Harbor will be deferred until the future reformulation study. " RARITXN BAY AND SANDY HOOK BAY HURRICANE AND STORM DAMAGE REDUCTION STUDY KEANSBURG^ EAST KEANSBURG^ AND LAURENCE HARBOR, NEW JERSEY November 2007 ES-ii Draft Environmental Assessment For purposes of economic analysis for this report, project economics and cost for consistency were both developed at the October 2006 price levels. The estimated total project cost, which includes the cost to construct the first renourishment operation in 2010 and the second partial renourishment in 2015 at Laurence Harbor is $12,828,000 ($8,338,000 Federal / $4,490,000 non- Federal). The estimated cost to construct the first renourishment operation is $11,669,000 ($7,585,000 Federal / $4,084,000 non-Federal). The estimated cost to construct the second renourishment operation is $1,159,000 ($753,000 Federal/$406,000 non-Federal). The estimated annual cost including interest, amortization and future renourishment is $347,000 with total annual benefits of $261,000. The benefit to cost ratio for the Laurence Harbor area is 0.8 to 1. The project will not be constructed at Laurence Harbor since it is not economically justified. Guidance outlined in Planning Guidance Letter (PGL) 22 recommends that the renourishment operations cover a period less than the maximum authorized under Section 506. For purposes of economic analysis, it was necessary to develop project benefits and costs for the complete project (2 operations in Keansburg and East Keansburg, and 2 operations in Laurence Harbor). In the spirit of PGL 22, the project will only include one renourishment operation at Keansburg and East Keansburg in 2009. The . total estimated cumulative construction cost of the recommended