About
Decatur Bridge
NDOT Project #: STP-51-7(109); CN 32395
Iowa DOT Project #: STP-175-1(106)--2C-67
Background:
The Decatur Bridge is a historic landmark that has provided regional connectivity for more than 70 years. Ongoing maintenance of the aging bridge indicates it is time to determine the appropriate long-term solution to provide continued access across the Missouri River. The proposed project would improve the Nebraska Highway 51 (N-51) / Iowa Highway 175 (IA-175) Missouri River crossing in Burt County, Nebraska and Monona County, Iowa. The Preferred Alternative described in the Environmental Assessment would construct a new bridge over the Missouri River approximately 80 feet north of the existing bridge.
Environmental Assessment:
The Decatur Bridge project Environmental Assessment is now available and can be accessed here:
The Environmental Assessment Appendices can be accessed here:
NDOT and Iowa DOT are also requesting feedback regarding the Environmental Assessment. All interested parties may submit comments and feedback by April 17th, 2026. Click here to provide comments and feedback:
The Environmental Assessment for this project is available for public review at the following locations:
- Decatur City Hall (913 S Broadway Street, Decatur, NE 68020)
- Onawa City Hall (914 Diamond Street, Onawa, IA 51040)
- NDOT District 3 Headquarters (408 N 13th Street, Norfolk, NE 68701)
- Iowa DOT District 3 Headquarters (6409 Gordon Drive, Sioux City, IA 51106)
- NDOT Headquarters (1500 Nebraska Parkway, Lincoln, NE 68502)
- Iowa DOT Headquarters (800 Lincoln Way, Ames IA 50010)
- FHWA Nebraska Division (100 Centennial Mall N, Suite 220, Lincoln, NE 68508)
- FHWA Iowa Division (105 6th Street, Ames, IA 50010)
Public Engagement:
The Nebraska Department of Transportation (NDOT) and the Iowa Department of Transportation (Iowa DOT) will hold a public hearing regarding the preliminary design and Environmental Assessment (EA) for the Decatur Bridge project in Burt County, Nebraska.
DATE: Tuesday, March 31st, 2026
TIME: 5:00 - 7:00 p.m. (CDT)
LOCATION: Decatur City Hall, 913 S Broadway Street, Decatur, NE 68020
Public Hearing materials will be made available March 31st, 2026.
Preferred Alternative
Q&A
Identified as Decatur Bridge, the proposed project would improve the Nebraska Highway 51 (N-51) / Iowa Highway 175 (IA-175) Missouri River crossing in Burt County, Nebraska and Monona County, Iowa.
The Preferred Alternative described in the Environmental Assessment would construct a new bridge over the Missouri River approximately 80 feet north of the existing bridge. Construction may begin just east of Broadway Street in Decatur, Nebraska and end approximately one mile east of the state line on IA-175 to accommodate the replacement of the structure.
The purpose of the project is to:
- Provide a resilient river crossing connecting Decatur, Nebraska/N-51 and Onawa, Iowa/IA-175 that maintains access to regional commerce, employment, education, health care, and recreation facilities.
- Maintain accessibility to and by emergency services.
- Provide infrastructure to support current and future travel demand.
Before we get to construction, the Decatur Bridge project planning and design will occur over three phases and multiple years outlined below. The earliest construction could begin is 2029.
Phase 1: Feasibility Study (Fall 2023 – Summer 2025) - Complete
This early assessment of the project began with environmental studies and public input to better understand existing conditions and future needs.
Phase 2: Preliminary Design & National Environmental Policy Act (NEPA) Decision (Summer 2025 – Summer 2026)
Alternatives will be considered, and preliminary plans will be developed as part of the NEPA decision-making process, resulting in a preferred alternative and an approved NEPA decision document.
Phase 3: Final Design (Anticipated to begin in 2026 following NEPA approval)
The preferred alternative will be advanced through final design and construction plans will be made.
*All dates and timeframes subject to change.
The next engagement event is a Public Hearing on March 31, 2026. Below is a recap of engagement opportunities held to date.
Two public information meetings were held in August 2024.
These meetings were preceded by a community-wide survey that was open for input February 1 through March 15, 2024.
Public outreach first began in January 2024 with a Community Advisory Group (CAG) meeting. About 25 local community representatives from Nebraska and Iowa committed to participate in the CAG which met on two distinct occasions.
Those interested in receiving email updates at key project milestones are encouraged to sign up!
The NEPA process is required by the Federal Highway Administration (FHWA) and determines if the project will have any significant impacts on the human and natural environment. The process takes 12 months to complete. The NEPA process is required to (1) obtain approval of the recommended proposed action by FHWA, (2) allow the use of federal funds for the project, and (3) support permitting and other approvals required under applicable laws and regulations (e.g., Clean Water Act [CWA], Endangered Species Act [ESA], National Historic Preservation Act [NHPA], Rivers and Harbors Act, Section 4(f) of the DOT Act.)
Document Library
Document Library
Location and Environmental Study
Location and Environmental Study:
NDOT and Iowa DOT initiated a Location and Environmental Study for the Decatur Bridge in April 2023 to develop and review options to improve the Nebraska Highway 51 (N-51) / Iowa Highway 175 (IA-175) crossing and can be accessed here:
As a part of the study, the project team received more than 1,000 responses to a community survey, established a Community Advisory Group, and hosted two public meetings. Materials from these meetings, including survey findings, are available for review at the bottom of this webpage.
Community Feedback Highlights
The following is a brief summary of the key takeaways from the community’s comments:
- Public meeting comments generally favored building a new bridge (submitted in August of 2024).
- Commenters preferred alignments that would maintain connectivity between Decatur and Onawa, minimize disruption to existing N-51 and IA-175 during construction (especially through Decatur), and remain as close to the existing bridge as possible.
- More than half, 53%, of the comments received mentioned the BLUE alignment as a preferred location and 32% of the comments received mentioned the ORANGE alignment as a preferred location. (Refer to the map below for alignment locations).
- In general, the sentiment of the formal public comments reflected the feedback communicated with the project team during the public meetings and as previously shared by the Community Advisory Group.
The following image shows the potential alignments for a new bridge crossing presented at the August 2024 public meetings. Two Build Alternatives, BLUE and ORANGE, are being recommended for further study under the National Environmental Policy Act (NEPA) decision-making process.
Previous Public Meeting Materials
August 2024: Public Meeting Materials
You can view the August 2024 Public Meeting presentation by clicking on the video below. Continue scrolling to find additional August 2024 public meeting materials.
