California Coastal Commission approves five-month project to clean up sediment.
CHULA VISTA — The city of San Diego received the green light to remove nearly 63 acres of bay bottom in Mission Bay, Oct. 12, as coastal commissioners approved a comprehensive dredging project during their October meetings in Chula Vista.
An estimated 483,880 cubic yards of sediment had accumulated in Mission Bay during a 10-year period between 1997 and 2007, according to California Coastal Commission staff.
Coastal Commission staff added the dredging project represents the largest action of its type in Mission Bay history.
Dredging the estimated 63 acres of bay bottom, according to Coastal Commission staff, would “improve public access and recreational opportunities in Mission Bay.”
“The project would restore the dredged areas to the original design elevation from when Mission Bay Park was first created by the City in the 1950’s. The dredged material will be used for two purposes, to restore beaches eroded beaches on Crown Point Shores and northeast Vacation Isle, and to fill subtidal depressions depleted by past dredging projects in Sail Bay and Leisure Lagoon,” Coastal Commission staff told commissioners in a report.
About 43 acres of the 63-acre dredging project is covered by eelgrass, according to Coastal Commissions staff. The eelgrass is home to sensitive habitat of birds, fish and invertebrates.
San Diego officials will plant a new bed of eelgrass in Mission Bay to offset the affected stretch of habitat in the area to be dredged.
A city analysis of Mission Bay sediment, conducted earlier this year, revealed about 483,880 cubic yard of sediment had accumulated at the bay bottom between 1997 and 2007.
“The sediment accretion was not uniform, but instead concentrated in certain parts of the bay such that the accretion eventually formed navigational hazards. The purpose of the dredging is to remove these hazards and improve recreational boating opportunities in Mission Bay,” Coastal Commission staff stated in its report to commissioners.
Dredging activity would begin in November and continue through March 2018, according to Coastal Commission staff.
Mission Bay Park is a 4,600-acre aquatic park – with 27 miles of coastline – within the city of San Diego. It is considered one of the largest parks of its kind in the country.
Boaters, kayakers and other water sport enthusiasts regular visit Mission Bay Park and partake in numerous on-the-water activities. Tidal mudflats primarily defined the area prior to the 1920s, but geological shifts during the 1930s and 1940s eventually helped create the Mission Bay people see today.
“Between 1948 and 1951 the San Diego River had been confined by the construction of northern and southern levees by the Army Corps of Engineers, thus ceasing its direct discharge of substantial amounts of sediment to Mission Bay. By 1955 offshore jetties were constructed to the north of the San Diego River mouth and north of the present day Mission Bay entrance channel,” Coastal Commission staff stated in a report. “The majority of the work constructing modern-day Mission Bay was completed by 1963. Mission Bay was the first and remains the largest west coast bay constructed for recreational uses.”
A wide diversity of motorized and personal watercrafts populates the waters of Mission Bay.
“The proposed maintenance dredging will increase the utility of Mission Bay Park above its current levels by restoring portions of the Bay to its original design depths, and widening three beaches,” Coastal Commission staff stated. “The proposed work will occur outside of the summer season to avoid impacts to the busy summer tourist season, when park visitation and recreational water activities are most common.”