In October, the City Council approved a contract with the firm Aquatic Environments to perform dredging in certain lagoons at Redwood Shores. This work will help specified areas of the lagoon to better “flush” and therefore improve water quality and appearance (please see www.redwoodcity.org/shoresdredging ).
As part of the outreach to affected residents, in addition to a direct mail flyer and an article in last month’s Pilot, the Redwood Shores Community Association and Redwood City hosted a project community information meeting on Thursday, October 22, 2009, during which residents heard from and asked questions of City staff, contractors, and consultants. At that meeting, staff provided an overview of the project, outlined the scope of work, and presented a tentative schedule. Here is a brief overview:
* The two areas to be dredged are the lagoon around Shorebird Island, and portions of the lagoon near Area H between Laguna Pointe and California Harbor Court.
* It’s expected that the contractor will begin prep work the first week of November, and start actual dredging a bit later in the month (a more specific schedule will be available on the project website in November).
* The work hours will be 7:30 am – 4:00 pm, weekdays only.
* While the contractor has up to 180 days to complete the work, it’s expected that the dredging will be completed by January 31st.
* Dredging will be done with one or two small barges which will hydraulically pump the sediment from the lagoon floor, sending it through a pipeline running along the main lagoon, to be deposited into Area H as part of the wetland restoration.
The key issues raised by residents attending the meeting, and summaries of staff responses, were:
* The expected noise levels of the dredge machinery and booster pump.
Some level of noise is unavoidable, but it is temporary. The contractor estimates that the noise of the pumps is similar to a mid-sized pickup truck engine. The expected noise level is approximately 80-85 decibels at 20 feet distance from the machinery. The machinery utilizes mufflers and is enclosed to minimize noise. We ask for residents’ patience throughout this project.
* Inability to launch boats from certain areas while the temporary pipeline is in place.
While it’s in place, it will not be possible for boats to cross over the pipeline, as it will be only partially submerged. This may be a particular issue for residents living on parts of Shorebird Island, and along the northern side of the main lagoon, for about a month while the Shorebird Island area is being dredged. Once Shorebird Island lagoon is dredged, the pipeline will be removed and boats will have easy access. The contractor will have floating buoys and markers attached to the pipeline to clearly indicate its location.
* There will only be partial dredging in the lagoon between Laguna Pointe and California Harbor Court.
Some parts of this lagoon contain the compound PAH (polycyclic aromatic hydrocarbons – likely from roadway runoff) in levels higher than is allowed for use as wetland restoration fill. Such sediment would have to be mechanically dredged and trucked to an alternate disposal site, at a significantly higher expense than disposal in Area H. Because of this higher expense, it is not financially feasible at this time for the City to dredge those portions of this lagoon – therefore only specified sections of this lagoon will be dredged. The City’s intent is to determine a way to finance the complete dredging of this area at a later date, once funds are fully available, likely several years away.
Much more information and diagrams are online at the City’s project website at www.redwoodcity.org/shoresdredging. There, you can also sign up to receive periodic updates via email.
The City and its contractor wish to thank the Redwood Shores community for its patience and understanding as this lagoon dredging project gets underway – the result will be an improved lagoon that more positively contributes to the beauty and pride of Redwood Shores, as well as the quality of life of its residents.