PENINSULA — Silt continues plaguing two local ports, threatening access and limiting moorage. Port Manager Guy Glenn Jr. is hopeful a remedy to the mucky situation will result from recent funding in the state’s supplemental budget.
On March 6, Washington legislators finalized Senate Bill 6095, including $450,000 to help the ports of Ilwaco and Chinook with marina maintenance dredging. Chinook and Ilwaco will receive $275,000 and $175,000, respectively. Lawmakers also provided $77,000 to explore options for sediment disposal, a crucial need as current disposal sites have reached or are near capacity.
“Current state funding should carry us through two to three years in Chinook while we work on a comprehensive approach for both marinas, including dredge material disposal alternatives,” Glenn said. Since 2016, the Port of Ilwaco and Chinook have operated under an interlocal agreement.
Port of Chinook
During low tide at the Port of Chinook, boats crowd the center fingers of the marina as shallower docks on the fringes remain vacant.
“The depth conditions in Chinook have made some areas inaccessible in the marina,” Glenn said. “We have areas in the marina where the docks sit in the mud at low tide.”
The Port of Chinook marina is federally permitted to minus 10 feet in the commercial dock area and minus 8 feet in the recreational dock areas. In February 2017, depths varied throughout the marina — ranging from 3.5 feet to 9 feet, and have worsened in some areas since.
“Silt continues to build up in the marina and we do our best to accommodate the needs of our moorage customers,” Glenn said. Compromises have already been made with some slips being restricted to shallow draft vessels only.
The rate of accumulation is unclear.
“A formal study has not been performed to determine the rate of siltation in our marinas,” Glenn said. “Chinook went several years without significant maintenance dredging leading to the buildup of material in their marina.”
Port of Ilwaco
The Port of Ilwaco started a maintenance dredging program nearly 20 years ago. Between 15,000 and 30,000 cubic yards of material are removed annually from the marina from Nov. 1 to Feb. 28, dates designated to avoid potential impacts with migrating salmon. The permitted depths in the Ilwaco marina range from 8-16 feet.
“The current conditions require us to perform annual maintenance dredging in our priority areas in Ilwaco,” Glenn said. “We continue to focus our efforts on maintaining access for commercial fishing vessels and maintaining access to our fuel docks and to our haul-out facility (Ilwaco boatyard).”
Commercial fishing vessels generally have a deeper draft in comparison with most recreational vessels, and count for more when it comes to keeping the port’s access open to the deeper waters of the Columbia River and Pacific Ocean.
“Commercial seafood tonnage and off-ship value landed at our ports is essential when advocating for federal funds to maintain our entrance channels connecting our marinas to the Columbia River and Pacific Ocean,” Glenn said. “Commercial seafood tonnage and the corresponding off-ship value are determining factors when advocating for federal funding to perform maintenance dredging in the Ilwaco and Chinook entrance channels.”
Addressing failing pile dikes — which are essentially walls to direct sediment away from navigation channels — along the outer portion of the Ilwaco entrance channel is also an ongoing concern for Glenn.
“A long-term investment in the pile dikes along the Ilwaco channel should ultimately increase reliability for channel users and decrease annual maintenance dredging costs with less pressure to dredge on an annual basis,” he said. “The pile dikes were originally designed to utilize the water current to scour the bottom and prevent the channel from silting in. These structures were constructed in the late 1930s and have not been maintained. They are separating from land and deteriorating leading to much higher rates of siltation in the channel.”
Disposal sites near capacity
Glenn said it is critical for both ports to find alternative dredge material disposal options. They will explore potential sites through the combined Ilwaco/Chinook dredge material disposal plan.
The Chinook upland dredge material disposal site is currently at capacity. The plan is to increase the capacity by managing the material on site to allow dredging in early 2019, Glenn said. The dredge material disposal site in Ilwaco is nearing capacity, despite years of managing the material on site. Up to 2,500 single dump truck loads of material are dredged from Ilwaco marina each year.
“We estimate in excess of 170,000 cubic yards of dredge material is currently contained at our upland dredge material disposal site in Ilwaco,” Glenn said. “It would fill over 14,000 single dump trucks.”
It would be “extremely expensive” to relocate the existing upland dredge material, according to Glenn.
“We would need to identify sites where it could be hauled to contingent on adequate funding,” he said.
Options for in-water disposal will be explored during the planning process.
“Dredge material would have to be transported by a submerged pipeline to a permitted location within one to two miles of our marinas in Baker Bay,” Glenn explained. “A booster pump may also be needed, adding additional expenses, along with the challenge of managing submerged dredge pipe in the strong tidal currents we experience at the mouth of the Columbia River.” Other alternatives may emerge during the planning process. Work on the Chinook upland disposal site will take place in the next four to six months to prepare for dredging in early 2019. Dredging in Ilwaco is planned to start Nov. 1.
“The funding we received from the State is greatly appreciated and we would like to thank Rep, Brian Blake, Sen. Dean Takko and Rep. Jim Walsh for their support,” Glenn said. “A more comprehensive approach is needed and this funding will buy us time to keep the priority areas maintained.”