The Borough of Stone Harbor conducted sediment dredging from all bay shore lagoons within the Borough associated with Great Channel, the main channel along the western margin of Seven Mile Island. Each lagoon was initially surveyed by the Coastal Research Center (CRC) prior to final permitting documents, then re-surveyed by the dredging contractor (Sevenson) prior to dredging and after each lagoon was completed. This means that the after-dredging survey dates vary between November 2016 and February 2017 as each lagoon was finished. The CRC returned as requested by the Borough and surveyed the entire lagoon set on October 3, 2017 to determine the changes that occurred and if new problems had developed. Although the CRC survey methodology represented a less dense survey pattern as compared to Stevenson’s post-dredging pattern, a review of the data shows that depths after dredging are essentially the same as those obtained immediately following sediment excavation. The noted localized changes in some lagoons appear to be the result of the different methodology rather than any accumulation or erosion of sediment. Good news!
The Beach and Bay committee of SHPOA recommends that the Borough consider having the CRC survey the Great Channel later in 2018 or in the first half of 2019.