What is Dredging?
Once the dredging schedule is released for Oceaside Harbor, it is usually immediately followed by an influx of questions: What is dredging? What is the purpose of dredging? And most importantly, is the beach still accessible while dredging is underway? To answer these questions, we sat down with the Harbor Maintenance Supervisor for the City of Oceanside, to debunk the fact from the fiction surrounding the annual beach and harbor maintenance protocol known as drudging.
What exactly is dredging?
Dredging is the process of digging up the sand that has accumulated at the entrance of the Harbor. The purpose is to keep the waterway deep enough to allow vessels to enter and exit the Harbor safely. Federal Waterways throughout the United States are controlled by the United States Army Corps of Engineers (USACE). They regularly measure the depth of our entrance. It is a federally funded program. The City of Oceanside does not pay to have the Harbor entrance dredged or to have the sand placed on the beach. The Oceanside Harbor District serves as the host for the program.
Why does the City of Oceanside need to dredge?
The dredge is important for several reasons, primarily to remove excess sand from the mouth of the Harbor. Through natural migration, the sand drifts into the entrance of the harbor and accumulates making the entrance shallow. Sailboats with long keels find it very difficult to navigate in the shallow entrance. The shallow water also creates a wave in the entrance which is dangerous for all vessels and their passengers. The large waves could tip a vessel over or create enough turbulence on board that would jolt passengers overboard. It is especially dangerous during low tide. The sand from the Harbor mouth is pumped onto the Oceanside Coastline allowing the City of Oceanside beaches to stay wide and sandy.
Is the dredging in Oceanside to be done mechanically or hydraulically?
The dredging is performed hydraulically. The dredge vessel knows where the sand is located. It is mapped out by survey of the bottom of the harbor entrance. The survey has been conducted by USACE. The dredge has a hydraulically operated auger that combs the bottom of the entrance sucking sand into the intake. A very large pumps sucks the sand into a pipe which runs along the beach and places the sand where it is needed as determined by the contractor and USACE. If the waves are large or the swell is very active the auger cannot maintain a steady contact with the sea bottom. Waves could cause the vessel to rise and lower rapidly which could cause damage to the auger. For that reason, even on a clear sunny day, dredging activity could be suspended until the swell calms.
Are you still able to access the beach?
Yes, visitors are still able to access the beach during this time and beach services are not interrupted during this process. Large pipes and heavy machinery are being used at varying locations on the beach; visitors are requested to stay away from the equipment (signage will be posted where the public is not allowed).
If you are boating in the Harbor entrance you should know the dredge vessel will put out anchor lines that boats should not cross. There will warnings on the dredge barge and warnings may be sent out to vessels via radio. When the operation begins they will move sand from the entrance of the Harbor and place it on Oceanside Beaches. Sand is placed along the shoreline where there is little or no sand to support the dredge pipe out of the water. Once an adequate amount is placed along the shoreline the pipe will be extended down the beach to the Oceanside Municipal Pier. The majority of the sand removed from the harbor entrance will be place on the South side of the pier. Heavy equipment is used to ensure the sand is placed where it is most beneficial. Portions of the beach will be closed off as this equipment is operated.
The fenced area around the South side of the San Luis Rey River is for the protection of the Western Snowy Plover. No one is allowed to enter this area with the exception of the environmental monitors hired by the dredge contractor.
Will there be issues with noise during the dredge?
When the product (sand) is taken from the bottom of the entrance a large number of rocks enter the pipe as well. These rocks bang against the pipe walls causing some noise surrounding the work zone. Another source of noise may be from the mechanical equipment used to put the pipes in place or move the sand up onto the beach. The equipment is only operated during daylight hours.
Are there any safety instructions that any beach-goers need to be aware of?
- This is a very interesting project and many people would like to come and watch the placement of the pipe in the Harbor entrance. It is usually placed by heavy equipment from the shore to the water. The contractor is a professional and has taken all precautions to ensure this procedure is performed safely. However, in order to maintain a safe environment the public should keep a safe distance from this activity at all times. Please keep an eye on your children.
- The dredge pipe south of the San Luis Rey River will be exposed. The contractor will make ramps available for the public to safely cross over the pipe. Please use these ramps. Climbing onto the dredge pipe is prohibited and may be dangerous. A fall onto the sand may seem harmless but you can get hurt. Please, for your safety, stay off of the pipe.
- Much activity will be going on at the discharge site of the pipe. Sand, water and rocks will be spewing out of the pipe at a high volume. The public is not allowed near the discharge area and will still need to stay away from the discharge end of the pipe.
- Heavy equipment will be operating on the beach. The operators are high off the ground and their visibility around them is limited. Their focus is on the placement of the sand. Again their work area will be fenced off and they will have spotters on the ground. Please stay away from heavy equipment on the beach at all times. The fenced area south of the San Luis Rey River is designated as a protected area for the Western Snowy Plover. The Contractor is required to monitor that area for the duration of the project. We ask that the Public not enter into the protected area at all times.
Where can I learn more about dredging in Oceanside?
Dredging is directed by the USACE. They contact the Oceanside Harbor as to any changes in the schedule or procedure. Due to weather and other factors, the schedule can change daily. As a result, information is not regularly posted onto the City of Oceanside Harbor website. For current information, please visit the Oceanside Harbor on Facebook or call 760-435-4031.