Geomorphic processes of Ship Creek in the vicinity of the Knik Arm Power Plant Dam
Dates
Year
2014
Citation
Straka, Nicholas B., 2014, Geomorphic processes of Ship Creek in the vicinity of the Knik Arm Power Plant Dam: University of Alaska Anchorage.
Summary
The bedload geomorphic processes of Ship Creek in the vicinity of the Knik Arm Power Plant (KAPP) Dam are unknown. These processes are necessary to understand the consequences of removing the KAPP Dam. With the aid of hydrologic flow modeling software, the induced shear stress was analyzed for a given flood event with and without the KAPP Dam in place. The shear stress was used to estimate the volume of bedload sediment transport related to a given flood event. The model showed that the removal of the KAPP Dam will increase the shear stress upstream for approximately 200 feet for a low-order event, and 400 feet for a high order event. This increase in shear stress indicates that the creek will become more susceptible to bedload transport [...]
Summary
The bedload geomorphic processes of Ship Creek in the vicinity of the Knik Arm Power Plant (KAPP) Dam are unknown. These processes are necessary to understand the consequences of removing the KAPP Dam. With the aid of hydrologic flow modeling software, the induced shear stress was analyzed for a given flood event with and without the KAPP Dam in place. The shear stress was used to estimate the volume of bedload sediment transport related to a given flood event. The model showed that the removal of the KAPP Dam will increase the shear stress upstream for approximately 200 feet for a low-order event, and 400 feet for a high order event. This increase in shear stress indicates that the creek will become more susceptible to bedload transport and thereby enhance erosion in this region. If the dam is removed, countermeasures will be necessary to maintain creek stability. While working on this thesis, it was observed that during a flood event when the KAPP Dam is being overtopped, sediment accumulates behind the dam, only to be flushed out with lower stream flow over the course of the summer months. Therefore, the dam does not permanently stop any sediment and any possibility of downstream creek bed elevation rise is dismissed. No bed elevation rise is assuming that if the dam is removed, the proper countermeasures will be put in place to stabilize the upstream creek bed.
