Southbridge Interchange Public Meeting
A public meeting to introduce the study area of the proposed Southbridge Interchange was held on December 15, 2016 at the Sergeant Bluff Community Center. Consulting engineering staff, Iowa DOT staff, and county officials were present to answer questions and provide information to attendees who stopped to learn about the progress on the project.
The project involves the preparation of an interchange justification report that will make a recommendation in regard to the need for an additional interchange with Interstate 29 south of the airport. Woodbury County, the Iowa Department of Transportation, the cities of Sioux City, Sergenat Bluff and Salix, and the Siouxland Inistiative are shairng in the expense of a project that is investigating the need for an additional I-29 interchange between the Port Neal Landing exit at mile point 135 and the Airport Interchange at exit 141. McClure Engineering (MEC) is the lead consultant for the project and is assisted in the project work by HDR Consultants, Inc. of Omaha .
Engineering work started last spring with laser scanned topographic surveys of the entire area bounded roughly between the Port Neal Road overpass at the north end, Port Neal Road on the west side, Old Highway 75 on the east side, and 260th Street, or county route D51 as the south project limit. Land use, boundary information, and prior surveys and studies have been collected by MEC and have been shared with HDR. HDR reviewed the Environmental Study Area boundaries in consultation with local officials and MEC staff. The study area was reviewed for pre-field investigation by archaeological and historic architectural property database searches, aerial photograph analysis for farmed wetlands, and hazardous material database review. Field crews have started and continue to work on the delineation of wetlands and other waters of the U.S., review of potential threatened and endangered species habitat, delineation of woodlands, archaeological and historic architectural property surveys, and hazardous material site reconnaissance. Photographs will be taken and data gathered from the field reviews, and compiled into reports for use in preparing an Environmental Assessment in compliance with the National Environmental Policy Act.
Some preliminary decisions have already been reached in the study process. A rail crossing within the interchange has been eliminated from consideration within the study following preliminary estimates of the cost of this accommodation. A separate I-29 rail crossing will studied separately in a future study. At last Thursday's meeting, three potential locations were identified as possible interchange locations (a map showing the locations is attached to this article). No corridors for connecting roads have been determined at this time. Attendees at the meeting had the opportunity to express their concerns to and ask questions of the consultants and state, county and city officials. As the study moves forward, more information will be shared as it is available.
The next phase of the study involves field investigation including a visual, pedestrian examination of the properties in the study area, soil borings to identify soil issues or wetlands, and field examination to determine whether there are any archaeological resources in the area. Investigation will extend into spring to see whether any wetland plant species emerge as warm weather returns. Report writing and preliminary study results and recommendations will be made to local officials late summer. A public hearing will be held to share results with everyone in the fall of 2017. Once the hearing is held, comments will be considered and the final report will be submitted to the cities, the county , and the Iowa DOT. The study is expected to be completed in December 2017.
The final report is submitted to the Iowa Department of Transportation and to the Federal Highway Administration. The agency review of the report is expected to take 6-9 months. If these agencies concur with the need for an additional interchange, the local jurisdictions will have be begin working to find funding for construction of a new interchange. At this time, there are no funds targeted to the construction of a new interchange.