The Engineering Department recommends approval of an expenditure in the amount of $659,101 for engineering professional services from Lockwood, Andrews & Newnam, Inc. for the Spring Creek Drainage Analysis - 15th Street to Plano Parkway. This project includes a detailed hydrologic and hydraulic analysis for Spring Creek and its contributing watershed from 15th Street to Plano Parkway.
Recent drainage studies have identified errors in previous FEMA modeling in the vicinity of the Collin Creek development. Corrections to the FEMA modeling now show the triple culvert system that conveys the flow of Spring Creek through the Collin Creek property could experience overtopping during a 100-year storm.
The first phase of this project will include a detailed analysis and development of alternatives to eliminate the overtopping during a 100-year storm. After the recommended solution has been identified, a professional services agreement to provide the engineering services necessary for the design of the chosen alternative will be developed and presented to the City Council for their consideration.
Lockwood, Andrews & Newnam, Inc. was deemed the most qualified firm based on their Statement of Qualifications submitted in response to RFQ No. 2024-0571-B and their experience with the City of Plano on hydrologic and hydraulic studies and the associated impacts to the floodplain in the Spring Creek area.
The benefit of this project includes resolving potential flooding concerns associated with the drainage system and updating the hydrologic and hydraulic model to current design criteria for the Spring Creek corridor.
Not approving the expenditure would result in not developing a solution to address the culvert capacity necessary for a 100-year storm and the continued potential for overtopping that would impact infrastructure and adjacent properties.