Intake Protection and Channel

The City of Aberdeen hired the IMEG and Wenck team to resolve problems with the water intake structure at their water treatment plant. The plant has a capacity of 12 MGD, serves 26,000 residents, and is located along the Elm River, the city’s source of drinking water. The existing concrete intake structure had intake screens constructed on wood piers within an oxbow along the river channel. Built in 1944, the structure had served its intended design life and was plagued by silt that restricted its capacity. A long-term solution was needed.

The project concept incorporated the natural aging of the river, where the oxbow would be bypassed eventually by river processes. The design was to construct a filter berm of rip rap to define the river channel, yet allow water to enter the oxbow to the intake. This allowed high sediment flows to remain in the main channel of the river and bypass the area of the intake. The oxbow was mechanically dredged to remove river sediment and increase the connectivity to the shallow aquifer. Wetlands were constructed within the oxbow to mitigate impacts from construction and utilize the natural river hydrology for reestablishment.

The project was less expensive than other alternatives, incorporated the natural aging of the channel, and allowed Aberdeen to address a long-term, ongoing project that threatened their existing intake. It allowed the city to continue utilizing existing infrastructure with no interruption of water service to residents.