SECTION 1. FINDINGS AND PURPOSE.

    (a) Findings.--Congress finds the following:
            (1) The John H. Chafee Coastal Barrier Resources System 
        (the System) was created by Congress when it enacted the 
        Coastal Barrier Resources Act of 1982 (CBRA). The System is a 
        collection of specific areas of land and associated aquatic 
        habitats delineated on maps adopted by Congress.
            (2) The System was expanded by amendments adopted in 1990 
        and currently contains 856 units and areas consisting of 
        approximately 3.1 million acres of undeveloped coastal land and 
        associated aquatic habitat.
            (3) The original non-digital System maps were based on 
        information that is now between 18 and 26 years old and were 
        drawn without precision. Since 1990, to avoid inequities and to 
        correct mapping errors, Congress has enacted 17 public laws to 
        modify 43 units.
            (4) The State of South Carolina has a well-established and 
        respected coastal management program to manage beachfront 
        development. The State's program is designed to protect 
        sensitive and fragile areas from inappropriate development and 
        to provide adequate environmental safeguards with respect to 
        the construction of facilities in the coastal zone.
            (5) Between 1988 and 1999, State and local regulations did 
        not authorize development of the western end of Kiawah Island. 
        However, in 1999, South Carolina established a setback line 
        that represents a detailed analysis of long-term accretion 
        trends in the area. Establishment of the setback line 
        authorized development of a portion of Captain Sam's Inlet Unit 
        M08 that was previously not authorized for development. In 
        2005, the Town of Kiawah Island's Town Council adopted a 
        Development Agreement to authorize and regulate development of 
        the area.
            (6) Kiawah Island is a world-renowned, environmental award 
        winning community known for responsible and sound development.
            (7) Kiawah Island and the associated beach, dune, and 
        hummock habitats provide a range of opportunities to increase 
        the ecological health and value to numerous native plant and 
        animal species.
            (8) To maintain the integrity of the System, the 
        modification of Captain Sam's Inlet Unit M08 described in 
        section 3 and the habitat enhancement actions described in 
        section 4 will increase the fish and wildlife habitat value of 
        the Unit and areas in proximity to the Unit.
    (b) Purpose.--Congress declares that it is the purpose of this Act 
to enhance the ecological value of Captain Sam's Inlet Unit M08 and 
areas in proximity to the Unit by modifying the Unit in a manner that 
adds 178 acres and removes approximately 61.5 acres which will soon be 
developed using a very low density approach, and by encouraging 
implementation of voluntary, supplemental ecological enhancement 
projects. The Unit modification will enable all residents of the area 
to be treated comparably.

SEC. 2. DESCRIPTION OF CAPTAIN SAM'S INLET UNIT M08.

    (a) In General.--Captain Sam's Inlet Unit M08 includes the area 
along Captain Sam's Inlet at Kiawah Island's western end. It was 
created in 1982 and expanded in 1990. The Unit currently includes the 
western end of Kiawah Island, neighboring fast land to the north and 
associated aquatic habitat. Current acreage of the Unit is 
approximately 1,182 acres, including roughly 200 acres of fast land and 
982 acres of associated aquatic habitat.
    (b) Unit M07/M07P or Bird Key.--A separate, much larger System unit 
covers the eastern portion of Kiawah Island. That Unit, known as Unit 
M07/M07P or Bird Key, is approximately 7,094 total acres, including 
roughly 687 acres of fast land and 6,407 acres of associated aquatic 
habitat.

SEC. 3. MODIFICATION OF CAPTAIN SAM'S INLET UNIT M08.

    (a) Net Expansion.--The replacement map referenced in section 5 
expands Unit M08 by 116 acres. The modified Unit increases in size from 
approximately 1,182 total acres to approximately 1,299 total acres 
(roughly 164 fast land and 1,135 associated aquatic habitat). The 
modification represents a ratio of approximately 3 acres added:1 acre 
removed.
    (b) Specific Changes.--The replacement map referenced in section 
5--
            (1) adds 178 acres to the Unit--25 acres of land in the 
        northeastern corner of the Unit and 153 acres of associated 
        aquatic habitat; and
            (2) removes 61.5 acres from the Unit--39 acres authorized 
        for development by the State in 1999 and rezoned by the Town of 
        Kiawah in 2005, and 22.5 acres on two adjacent islands.

SEC. 4. SUPPLEMENTAL PROJECTS TO ENHANCE ECOLOGICAL VALUE.

    (a) Density Reductions and Conservation Easements.--
            (1) There are existing entitlements for 44 dwelling units 
        on the 25 acres of fast land that are being added to the Unit. 
        To increase the habitat value of the modified Captain Sam's 
        Inlet Unit M08, the owners of this land have indicated a 
        willingness on a voluntary basis to reduce substantially these 
        entitlements and grant conservation easements to an appropriate 
        conservation organization.
            (2) There are existing entitlements for 460 dwelling units 
        on the 61.5 acres that are being removed from the Unit. To 
        increase the habitat value of the modified Captain Sam's Inlet 
        Unit M08 and the area being removed from the Unit, the owners 
        of this land have indicated a willingness on a voluntary basis 
        to reduce substantially these entitlements and, as a result, 
        reduce allowable density.
    (b) Ecological Enhancement.--
            (1) A privately funded project is being developed to 
        increase the ecological health and habitat value of the 
        modified Captain Sam's Inlet Unit M08 and related habitat in 
        and around Kiawah Island. The South Carolina Department of 
        Natural Resources, the U.S. Fish and Wildlife Service, and 
        regional and local officials and interested conservation groups 
        are being consulted about project design and implementation.
            (2) The project is being designed as a valuable public-
        private partnership project to increase the overall ecological 
        value of habitats for a diversity of native fauna and flora. 
        Species likely to benefit will range from culturally and 
        ecologically significant plant species such as sweetgrass 
        (Muhlenbergia filipes), to indicator mammalian species such as 
        the bobcat (Felis rufus), and declining or threatened avian 
        species such as the piping plover (Charadrius melodus) and 
        painted buntings (Passerine ciris).

SEC. 5. REPLACEMENT OF COASTAL BARRIER RESOURCE SYSTEM MAP RELATING TO 
              CAPTAIN SAM'S INLET UNIT M08 IN CHARLESTON COUNTY, SOUTH 
              CAROLINA.

    (a) In General.--The Coastal Barrier Resource System map of Captain 
Sam's Inlet Unit M08 that is dated October 24, 1990, and included in 
the set of maps referred to in section 4(a) of the Coastal Barrier 
Resources Act (16 U.S.C. 3503(a)), is replaced by the map of the unit 
entitled ``John H. Chafee Coastal Barrier Resources System Captain 
Sam's Inlet Unit M08'' and dated March 2008.
    (b) Availability.--The Secretary of the Interior shall keep the 
replacement map referred to in subsection (a) on file and available for 
inspection in accordance with section 4(b) of the Coastal Barrier 
Resources Act (16 U.S.C. 3503(b)).
Replaces the John H. Chafee Coastal Barrier Resources System map "Captain Sam's Inlet Unit M08" (an area in South Carolina) with a map of the unit entitled "John H. Chafee Coastal Barrier Resources System Captain Sam's Inlet Unit M08," increasing the size of the unit.
To modify Captain Sam's Inlet Unit M08 of the John H. Chafee Coastal Barrier Resources System in Charleston County, South Carolina, and to revise the System map relating to the unit.