Because of urbanization, the Red Clay Creek at Stanton Delaware had been experiencing severe erosion for the last four decades threatening homes that had been constructed near its banks. To protect their homes, the residents of these homes had constructed a series of masonry and rubble retaining walls. By the mid-1990’s these walls had begun to collapse. Their deteriorated condition not only posed a threat to children, but the collapsing walls fell into the stream obstructing flows and causing even more erosion. Finally, the loss of the protective walls also threatened the homes located behind them.

Duffield Associates was retained to study the problem and develop a solution. Our engineers and scientists, after conducting modeling studies to evaluate stream hydraulics and morphology, recommended construction of an innovative and aesthetically pleasing retaining wall and installation of two innovative rock “flow vanes” to naturally channel and redirect the stream’s energy and erosive forces. This project, which represents the first large-scale use of Flow Vanes in Delaware, has been instrumental in stabilizing the stream’s form and dimension while protecting adjacent residential properties. The greatest test to the project occurred in September, 1999, when Hurricane Floyd caused rampaging flooding in the Red Clay Creek and the adjacent community. The retaining wall and Flow Vanes successfully weathered Floyd which was assessed as being a 500 year frequency storm. Our design solution received the Consulting Engineers Council of Delaware’s Grand Conceptor Award for Engineering Excellence and the top award from the American Society of Civil Engineers (Delaware).