Articles

The Rush Creek watershed contains approximately 31,000 highly urbanized acres and approximately 72 miles of main channel and tributary.  The watershed has developed significantly over the past 40 years, while City stormwater ordinances allowed development without considering cumulative downstream impacts.  This has had a significant impact on the floodplains and creeks and has led to increased volumes, velocities and base flood elevations as well as decreased water quality.  The watershed hydrologic modeling has not been updated to take this period of development into account. 

On September 8, 2010, the Rush Creek Watershed experienced a significant flood event.  Over 200 homes were reported to have flooded and the event is estimated to be about a 50-year event.  This flood sparked two major projects and the passing of the City’s first stormwater bond for $41 million with $18 million dedicated exclusively to buyouts and studies.  About six months after the flood the City Council preliminarily approved a comprehensive watershed study to update the floodplain maps and identify flood and erosion control projects.  

We have now almost completed one of the first basin-wide unsteady state models in North Texas.  The complexities of the watershed and interactions between the tributaries and the main stem necessitated unsteady state and 2D modeling.  The Rush Creek Watershed Study has been broken up in order to hasten the study process by adding more modeling resources than one firm could provide.  A project management consultant is overseeing the effort and acting as an extension of City Staff.  Hydrology and a stream stability analysis are being completed basin-wide while three sub-consultants are modeling the hydraulics of the watershed and identifying future CIP projects.  The end result will be an accurate depiction of the flood risk in the watershed, updated FEMA mapping, and a Comprehensive Watershed Plan that identifies Capital Improvement Projects for flood risk reduction, erosion mitigation and water quality improvement.

 

Presenters:

Audra Valamides, PE, CFM is a stormwater engineer for the City of Arlington. She has experience with land development, flood mitigation, stormwater infrastructure, watershed studies, MS4 Permitting and regional program management of the North Central Texas Council of Governments’ Public Works Council and Floodplain Management Task Force. She earned a Bachelors of Science in Civil Engineering and a Master of Engineering in Environmental Engineering from the University of Texas at Arlington. 

 

Dan Buhman, P.E. is a water resources engineering specialist with particular emphasis on hydraulic and hydrologic analysis, water supply planning, channel stabilization and restoration design, and stormwater analysis.  He holds a B.S. from Brigham Young University, an M.S. from Colorado State University.  Dan’s experience in stormwater/floodplain management includes the application of one-, two-, and cutting edge three-dimensional hydraulic models to simulate river mechanics, delineate floodplains, and design whitewater boating channels.  He works in CDM Smith’s Fort Worth and Dallas offices and works on projects throughout Texas.