SUPPLEMENTARY INFORMATION:

Background

GSA is beginning preparation of a SEIS to analyze the potential impacts resulting from the proposed realignment and reconstruction of the Rose Avenue Channel and construction of a new stormwater retention basin west of the expanded and modernized RHC LPOE. This SEIS will supplement the previous Environmental Impact Statement (EIS) for the RHC LPOE expansion and modernization project. GSA signed the Record of Decision (ROD) for the Final EIS for the Expansion and Modernization of the RHC LPOE and Proposed Commercial LPOE in Douglas, Arizona on May 6, 2024. GSA approved the preferred alternative, identified in the Final EIS as Alternative 2 (Concurrent Construction—Westward Expansion), which would involve construction of a new Commercial LPOE and phased expansion and modernization of the existing RHC LPOE at the same time, with expansion primarily to the west of the existing RHC LPOE.

Under the Proposed Action for the SEIS, the existing concrete box culvert beneath the LPOE would be partially maintained and extended westward near the existing vehicle inspection booths. From there, an open channel would be constructed generally parallel and to the north of Border Road and would discharge into an existing wash just west of Chino Road. The existing north-south channel that runs parallel to Pan American Avenue would be abandoned and sealed or demolished in conjunction with the expansion and modernization of the RHC LPOE. An expanded stormwater retention basin would also be constructed just west of ( printed page 81530) the existing Alternative 2 Expansion Area as identified in the Final EIS. In addition to the Proposed Action, GSA will also consider the No Action Alternative.

The purpose of the Proposed Action is to address stormwater management and flood control needs for the expanded and modernized RHC LPOE. The need for the Proposed Action is that the current alignment of the Rose Avenue Channel will result in engineering conflicts with the current proposed layout for the expanded RHC LPOE and requires re-routing. Additional land area is also required for necessary stormwater retention at the expanded and modernized RHC LPOE.

Preliminary analysis indicates that short-term adverse environmental impacts may occur during construction on air quality and greenhouse gases from emissions; geology and soils and water resources from ground disturbance; and biological resources from ground disturbance and construction noise. GSA will be conducting a jurisdictional determination, archaeological survey, and Phase I Environmental Site Assessment to inform potential impacts to Waters of the United States, cultural resources, and human health and safety, respectively. Minimal or no impacts are expected to occur to the following resources: transportation and traffic; noise; socioeconomics, and environmental justice. Beneficial impacts are expected to infrastructure and utilities from the improvement of stormwater management facilities. The Proposed Action may require acquisition of additional land to the west of the RHC LPOE. Necessary permits and authorizations will be identified within the Draft EIS.

The Draft EIS is expected to be published in early 2025.