Confronted with the possibility of continuing water shortages in northern Delaware, United Water Delaware sought to develop a more reliable water source for its Stanton Treatment Plant. They hired Duffield Associates to determine how to increase its intake of raw water from the White Clay Creek without disturbing the stream’s ecosystem.

Our design solution received the Consulting Engineers Council of Delaware’s Grand Conceptor Award for Engineering Excellence and the Water Resources Association’s Special Recognition Award.

Use of the almost inexhaustible quantity of water available in the White Clay Creek’s twice-daily freshwater flood tide is restricted by a regulatory requirement mandating the maintenance of a minimum downstream flow. We developed an innovative solution using an expandable water-filled bladder that inflates at peak high tide to impound and hold the tidally supplied fresh water. The period of high tide is essentially extended -- allowing United Water to pump the water into their treatment plant and meet their customers’ supply needs. The bladder is then deflated to allow the creek to flow naturally. Although similar technology has been used for irrigation projects in other parts of the world, the Tidal Capture Structure represents the first known application of this technology for water supply purposes in North America.