E5-6642. Intent To Prepare a Draft Environmental Impact Statement for Potential Multipurpose Projects for Ecosystem Restoration, Flood Damage Reduction, and Recreation Development Within and Along the West and Elm Forks and Main Stem of the Trinity ...

AGENCY:

Department of the Army, U.S. Army Corps of Engineers, DoD.

ACTION:

Notice of intent.

SUMMARY:

The study is being conducted in response to the authority contained in the following United States Senate Committee on Environment and Public Works Resolution dated April 22, 1988, as quoted below:

Resolved by the Committee on Environment and Public Works of the United States Senate, that the Board of Engineers for Rivers and Harbors is hereby requested to review the report of the Chief of Engineers on the Trinity River and Tributaries, Texas, House Document No. 276, Eighty-Ninth Congress, and other pertinent reports, with a view to determining the advisability of modifying the recommendations contained therein, with particular reference to providing improvements in the interest of flood protection, environmental enhancement, water quality, recreation, and other allied purposes in the Upper Trinity River Basin with specific attention on the Dallas-Fort Worth Metroplex.

An initial assessment based on the resolution guidance indicates a Federal interest in continuing with more detailed studies for these purposes. In accordance with the National Environmental Policy Act, a Draft Environmental Impact Statement (DEIS) will be prepared to evaluate and compare ecosystem restoration, flood damage reduction, and recreation alternatives within and along the Trinity River in, within and adjacent to the existing Dallas Floodway area of Dallas, TX. The DEIS will also assess the impacts to the quality of the human environment associated with each alternative. The study area will be bound on the upstream by Loop 12 crossings of the West and Elm Forks and at the downstream end by the existing terminus of the Dallas Floodway approximated by the abandoned Santa Fe railroad on the Trinity River. The construction and implementation of Joe Pool Lake, Grapevine Lake, Lake Lewisville and the Dallas Floodway project along with urbanization and development activities, have significantly degraded the terrestrial and aquatic habitat along and within the Trinity River. Consequently, ecosystem restoration measures will be developed and evaluated to address the degraded habitats. In addition, recreation measures will be developed and evaluated as complements to proposed ecosystem restoration measures. Preliminary findings indicate that due to major changes in runoff attributable to upstream development, the originally authorized flood damage reduction benefits have diminished within the study area and therefore opportunities to restore those Floodway benefits and explore options for improving flood damage reduction benefits within the interior drainages in the study area should be investigated. Flood damage reduction measures will address the loss of the authorized level of flood protection for the area.

DATES:

A public scoping meeting will be held on December 13, 2005 at 7 p.m.

ADDRESSES:

The meeting will be held at the Nash-Davis Recreation Center Activity Room, 3710 North Hampton Road, Dallas, TX 75212.

FOR FURTHER INFORMATION CONTACT:

Questions pertaining to the proposed action and DEIS can be answered by: Mr. Gene T. Rice, CESWF-PM-C, U.S. Army Corps of Engineers, Fort Worth District, P.O. Box 17300, Fort Worth, TX 76102-0300, [phone].

SUPPLEMENTARY INFORMATION:

The original Dallas Floodway levees and interior drainage improvements were completed between 1928 and 1931 by the City of Dallas and Dallas County Levee Improvement District. The Trinity River was rerouted by constructing a channel within the leveed floodway. The original channel was either filled or used for sump storage.

In the mid-1940's, major floods, compounded with continued urbanization in the watershed draining into the Floodway system resulted in severe flooding. The Dallas Floodway was authorized by River and Harbor Acts of March 2, 1945 and May 17, 1950. The project, which was completed in April 1959, entailed the channel improvement, clearing of the floodway, strengthening of levees, installation and modification of drainage structures, construction of pressure sewers, pump station and sump areas. The improvements provided conveyance of the Standard Project Flood within the floodway plus 4 feet of freeboard.

Alternatives for ecosystem restoration, flood damage reduction, and recreation will be developed and evaluated based on ongoing fieldwork and data collection and past studies conducted by the Corps of Engineers, the City of Dallas, and the U.S. Fish and Wildlife Service. Ecosystem restoration alternatives that will be evaluated include creating meanders within the Trinity River, restoring, protecting and expanding the riparian corridor, improving aquatic habitat, creating riffle-pool complexes, and constructing wetlands. It is anticipated that ecosystem restoration measures would aid in improving water quality, optimizing aquatic and terrestrial habitat, and minimizing erosion and scouring along and within the river. Alternatives for flood damage reduction measures will be evaluated from both a non-structural and structural aspect. Non-structural measures that will be evaluated include acquisition and removal of structures or flood proofing of structures for protection from potential future flood damage. Structural measures that will be evaluated include levee height modification by fill or addition of flood walls, changes in interior drainage by enlarging storage areas or increasing widths and depths and/or a combination of these measures. Recreation measures that will be evaluated for include multipurpose trails and passive recreation features, such as interpretive guidance and media and picnic areas. Recreation measures will be developed to a scope and scale compatible with proposed ecosystem restoration measures without significantly diminishing ecosystem benefits.

A Programmatic Environmental Impact Statement (PEIS) for the Upper Trinity River Basin Feasibility study addressing the potential cumulative effects of reasonably foreseeable projects, including the Clear Fork West Fork studies was completed in June 2000. The DEIS will be tiered to the PEIS.

The public will be invited to participate in the scoping process, invited to attend public meetings, and given the opportunity to review the DEIS. The first public scoping meeting will be on (see DATES & ADDRESSES). Subsequent public meetings, if deemed necessary, will be announced in the local news media. Release of the DEIS for public comment is scheduled for March 2007. The exact release date, once established, will be announced through mailings to known interested individuals, agencies and officials and in the local news media.

Future coordination with other agencies and public scoping will be conducted to ensure full and open participation and aid in the development of the DEIS. All affected Federal, state, and local agencies, affected Indian tribes, and other interested private organizations and parties are hereby invited to participate. Future coordination will also be conducted with the United States Fish and Wildlife Service (USFWS). The USFWS will furnish information on threatened and endangered species in accordance with the Endangered Species Act. In addition, the USFWS will also be requested to provide support with planning aid and to provide a Fish and Wildlife Coordination Act Report. The State Historic Preservation Office will be consulted as required by Section 106 of the National Historic Preservation Act.

John C. Dvoracek,

Lieutenant Colonel, Corps of Engineers, Deputy District Engineer.