Duchesne & Hawthorn Culvert Replacements

Impacted Ward: 7
Design Consultant: George Butler Associates (GBA)

Project Description

The existing culverts under Hawthorn Ave and Duchesne Drive on Boschert Creek do not adequately convey existing storm water flows and are the cause of frequent flooding of properties upstream of the culverts. The City of St. Charles Comprehensive Stormwater Masterplan identified the flooding issues, and anticipated replacing the existing structures with new Reinforced Concrete Box (RCB) Culverts. The design will include HEC-RAS modeling to determine the actual size and final layout of the culverts for construction. Following completion of construction, the City intends to submit a Letter of Map Revision (LOMR) to FEMA to remove adjacent structures from the floodplain.

Boschert Creek between Hawthorn Ave and Pine Street was identified in the Comprehensive Stormwater Masterplan as widening with bank failures in several locations. Repairs have been attempted with dumped rock. Though not identified in the masterplan, the creek banks between the culverts will also be evaluated to determine whether additional stabilization is needed. The project will include stabilization of the creek banks along this reach by use of grade controls, revetment, native vegetation, etc.

Project Location

Boschert Creek near between Pine Street and Duchesne, under Hawthorne Avenue.
Hawthorn Culvert
Duchesne Culvert

Improvements

  • Box culverts will be replaced to help with back up during heavy rain. 
  • New retaining walls will be constructed. Roadway elevation at Hawthorn Avenue will be raised slightly. 
  • Sanitary sewer and water main will be replaced. 
  • New 6-foot wide sidewalks added to both sides 

Schedule

Project is still in planning stages. Construction is expected to start Spring of 2022.

Related Documents

Contact Information

Kierstyn Lorince
Project Manager
636-949-3237
Kierstyn.Lorince@stcharlescitymo.gov  

Project Activities

  • Crews performed soil borings and survey beginning in August 2020.
  • Designer submitted Alternatives Analysis report in September 2020 for replacing the culverts. 
  • As of October 2021, easement acquisitions have been completed. Construction expected to begin in Spring 2022.
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