PRHP completed work on the south  bank cofferdam on April 7, 2017. The 1.6 km-long cofferdam has been constructed along the south bank of the Peace River and is a temporary structure that works as a barrier to impede groundwater seepage during construction of the next phase of the project.

The construction of the cofferdam will allow PRHP to start the dewatering and RCC excavation from the water elevation down to the bedrock. The cofferdam consists of an earth-fill embankment with slurry cut-off wall core, which is up to 18 m depth in average. Construction activities on the footprint of the cofferdam commenced on August 2016 and were completed in early April 2017, with approximately 120 employees working per day to complete this portion of the project.