Macroscale Urban Culvert Daylighting & Stream Restoration, Flooded with Challenges, Innovation, and Restoration Success
Matthew D. Gramza, PE, CFM, CPESC
Civil & Environmental Consultants, Inc.
Cincinnati, OH
The former Hartwell Golf Course began operation in the mid-1930s when a large portion of the Congress Run Valley in Urban Central Cincinnati was culvertized and the floodplain disconnected. One fairway was originally built over top of the culvert and over the next decade the culvert was extended to accommodate a total of three fairways. The resulting structure was a 10.5-foot span by 7.5-foot rise metal arch culvert over 540 feet long with near complete floodplain disconnection. The project site is located on Congress Run, a Tributary of Mill Creek and includes a 3.8 square mile drainage area to the culvert. Increased precipitation/hydrologic peak flows, urban watershed development and the resulting stream hydromodification compounded with the lack of floodplain contributed to major repetitive flooding issues at the now undersized culvert. The former golf course was being decommissioned for alternative land use and several flood mitigation solutions were evaluated. The selected mitigation approach included daylighting of the culvert, stream restoration of Congress Run and complete reconnection to the floodplain unseen in nearly a century. The project was full of challenges including, location in a FEMA Flood Zone AE with backwater effects from the Mill Creek Confluence, record rainfall resulting in very flashy stream flow management required during construction, approximately 20,000 cu. yds. of relatively unknown type and environmental condition valley fill soils to cost-effectively excavate and manage, high voltage overhead utilities, large sanitary sewer main, etc. etc. etc. Innovative design solutions were implemented including, a two-phase project approach to install a temporary flood mitigation overflow channel for immediate flood relieve and use as a stream diversion around the proposed stream restoration, Unmanned Aerial Systems (UAS) for pre and post-project condition assessment, photo, and video documentation, and 2D Hydraulic Modeling utilized to optimize the stream restoration geomorphological design including in-stream and bank stabilization structures, and management of channel and bank shear stresses in addition to the FEMA Floodway No-Rise Analysis. Construction was recently completed and a post-construction UAS flyover will be presented along with lessons learned related to design and construction for insight on future projects.
About Matthew D. Gramza, PE, CFM, CPESC
Matt Gramza is a Water Resources Engineer, Certified Floodplain Manager, and Certified Professional in Erosion and Sediment Control with more than 20 years of experience. He has a Bachelor of Science in Civil Engineering from the University of Cincinnati and is registered as a Professional Engineer in five states. He currently serves Civil & Environmental Consultants, Inc. as a Principal and Water Resources Practice Lead in the Cincinnati Office. His project experience includes stream restoration assessment, design, and construction management, advanced riverine hydrologic and hydraulic analysis, stormwater management, erosion and sediment control design and inspection, floodplain management, dam safety including dam breach analysis, site design and infrastructure engineering in the public and private sectors.