Complete question: Was heavy machinery used to on the bridge and deck at Horseshoe Lake dam for recent parapet work and could that have contributed to further and more drastic deterioration and weakening of the dam and spillway?
Answer: The equipment used to make the recent repairs to the observation deck would have had minimal, if any, impact on the structure. The forces of the equipment on the deck are more vertical in nature. It is our understanding, the structural instability of the dam and spillway structure are primarily a result of the hydraulic pressure (which is horizontal). While backfilling the excavation, we purposely placed material in lifts to minimize the hydraulic pressure. Also, the material used did not require any a vibratory equipment for compaction as this may have led to additional damage.
Posted August 6 in response to question submitted for August 9 public meeting.