The Seattle District U.S. Army Corps of Engineers plans to make repairs to approximately 200 linear feet of deteriorated Point Chehalis revetment sometime in late August or early September. The project is expected to take two to three days to complete. The section that will be rehabilitated is approximately 200 feet in length and lies directly northwest of the Port of Grays Harbor Viewing Tower at the foot of Neddie Rose Drive.
A Corps survey completed in December 2009 indicated the structure in that area known as Section A is approximately 2-3 feet below the authorized crest height. According to the study, “Smaller core rock has been dislodged from the structure matrix resulting in a more porous structure. Recent engineering analysis has determined that wave energy has increased in the area over the past ten years due to significant morphology of the channel throat immediately north of Point Chehalis. As a result, the frequency and degree of overtopping has increased resulting in progressive structural damage. The scheduled repairs are intended to prevent further instability to the structure where damages have been observed.”
Workers will remove the existing large armor rock at the top of the revetment in that section in order to restore the intermediate core rock section that has washed away. New core rock will be installed to support a reworked armor rock layer. The submerged toe rock layer will be also be restored to provide additional stability to the outboard slope of the structure.
City of Westport officials hope that the work will decrease the amount of wave overtopping along that section of the revetment during storm events pushed by westerly winds and high tides. The excess water regularly floods Westhaven Drive and Neddie Rose Drive. In addition to inundating business buildings along both streets, the excess water has caused extensive erosion damage along the Westport Marina bankline in the Islander Resort RV Park. Recent upgrades to Westhaven Drive include a drainage system down the middle of the street with added vaults to channel water into the marina that are expected to help with flooding.
The Islander Resort RV property was also recently repaired with the addition of an open rock-lined drainage ditch alongside the motel units that is hoped to protect the bankline from further erosion. Despite hopes that the revetment repair will help with the flooding situation, the Corps of Engineers has been very clear in specifically stating that, “The repair is not intended to eliminate wave overtopping and water flow over the structure.” The Corps’ mandate in this area is to maintain the Grays Harbor shipping channel and the Westport boat basin. The revetment wall along Pt. Chehalis supports both those mandates.
The revetment, in combination with the system of six groins that start near the Observation Tower and run out to the end of Pt. Chehalis, stabilizes the Point against erosion and protects the boat basin at Westhaven and its navigation access channel. The River and Harbor Act of August 30, 1935 authorized the Grays Harbor and Chehalis River Project, including associated operation and maintenance of the Federal navigation channel. Additionally, Federal maintenance of the entrance channel to the boat basin at Westhaven was authorized in the River and Harbor Act of 1948. The same Act authorized construction of the Point Chehalis revetment in 1972. Different sections of the revetment have been periodically rehabilitated over the years since. Project Permitting The revetment repairs are being performed under the provision of a Categorical Exclusion under the National Environmental Policy Act because the work is routine repair and rehabilitation.
The project is also exempt from a requirement for a Clean Water Act Water Quality Certification because the repair of the revetment will not alter the character, scope, or size of the initial revetment and constitutes maintenance of a currently serviceable water control structure. According to project documents, the Corps has determined that the proposed project would have no effect on Environmental Species Act listed species or critical habitat. In addition, after construction is completed, the minimal construction footprint would be expected to quickly recolonize with organisms from adjacent areas resulting in formation of a similar community within a year’s time.
The Corps has also determined that the proposed project is consistent to the maximum extent practicable with the enforceable polices of the Washington Coastal Zone Management Plan, Lands in the vicinity of the project area have accreted since 1870, therefore it is unlikely that buried archaeological resources materials exist within the project site, therefore it is believed that no resources included or eligible for inclusion in the National Register of Historic Places would be affected by the proposed project.
*story courtesy Barb Aue, South Beach Bulletin July 15, 2010
