Summary of Floodplain Impacts Required for the SR-123 Roundabout
SUMMARY OF FLOODPLAIN IMPACTS
Date: October 23, 2023
Project ID: WAR-SR123-29.40 Community Park Pl D 110740
Floodplain Affected: Clear Creek
Description of Project:
The City of Franklin, in cooperation with the Ohio Department of Transportation (ODOT) District 8, proposes to improve the intersection of State Route (SR) 123 and Franklin Community Park. The project includes the construction of a new roundabout serving SR 123, the entrance to the Franklin Community Park, and a proposed driveway that will serve the new Franklin High School and includes drainage, pedestrian sidewalk improvements, and lighting. Currently, SR 123 is a curbless two-way, one-lane road with a dedicated left hand turn lane into Community Park Drive. There is no current access point to the proposed new Franklin High School. Construction is anticipated to begin January 2024 and continue for approximately eight months.
Why must this project be located in the Floodplain?
The purpose of the project is to improve traffic flow and promote intermodal connectivity by addressing congestion and pedestrian facility deficiencies at the existing intersection of SR 123 and Community Park Drive. High peak traffic volumes for special events at Franklin Community Park complex have resulted in traffic congestion at the existing intersection. The current traffic issues combined with the future recreational developments on the west side of SR 123, as is noted in the Franklin Community Park Expansion Plan, will result in further degradation of traffic flow during future special events.
The project must be located in the floodplain in order to address the deficiencies of the existing intersection to meet the project purpose. The work is considered maintenance that does not change the alignment, grade, or hydraulic capacity of the existing structure. Because of this, the project is exempt from the normal permit process required for work encroaching on a SFHA
What alternative sites were considered, if any?
Alternative sites were not considered for this project, as the existing intersection is located within the 100- year floodplain of Clear Creek.
Were any mitigation measures utilized on this project? If so, please describe.
No adverse floodplain impacts to adjacent properties or structures are anticipated as a result of this project, as the project is considered maintenance that does not change the alignment, grade, or hydraulic capacity of the existing structure. The proposed work will not result in an increase to the Base Flood Elevation over the 1-foot allowable surcharge. Therefore, no mitigation measures are required to reduce floodplain impacts from this project.
To the best of my knowledge, this project has complied with all applicable Local, State, and Federal Floodplain protection standards.
Eric J Troyer, P.E.