Trinity Parkway Environmental Impact Statement

Halff completed the Environmental Impact Statement (EIS) for Trinity Parkway, one of the most complex and controversial roadway projects in the United States and a high-priority project under Presidential Executive Order 13274.

Halff evaluated impacts to the natural and human environments that would result from this 9-mile, six-lane tollway providing a reliever route to help manage congestion on the existing freeways in the downtown Dallas area.

Several alternatives were evaluated, including alignments located in and along the Dallas Floodway, a federal flood conveyance and levee system for the Trinity River. The total estimated project cost was $1.4 billion.

The development of the EIS included exhaustive data collection, field surveys, impacts analyses, agency coordination, public involvement and mitigation planning. Constant communication among Halff’s environmental team and engineers, as well as continuous coordination with agency technical staff and legal counsel, was instrumental in ensuring the proposed transportation solution complied with environmental laws.

The FHWA, TxDOT, NTTA and City of Dallas were project sponsors, and the U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers (USACE) were cooperating agencies. The EIS was closely coordinated with these agencies. More than 20 other resource agencies, including the Federal Emergency Management Agency (FEMA), U.S. Fish and Wildlife Service, Texas Parks and Wildlife Department, Texas Historical Commission and Texas Commission on Environmental Quality, participated in the environmental review process.

The project involved complex and significant environmental impacts, garnered intense media and public scrutiny, and required extensive coordination with other planned projects in the area, including other transportation projects, parks and recreational plans, and flood control improvements. Halff guided the project through complicated regulatory frameworks and was successful in obtaining a Record of Decision from the FHWA.