Res10 P-2095 - Laserfiche WebLink

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i Existing Site Conditions: The existing facility is 25 years old and portions have deteriorated extensively in the marine environment. The most deteriorated portions are the concrete abutment and pier,metal gangway and floating dock that provide passenger access to boats,once the boats are launched into the water. Project Description: The project is a replacement and associated improvements to the gangway/dock between Wharf No.4 and the Public Access Area. It includes demolition of the existing concrete sidewalk abutment and pier, gangway,piling and floats. The sidewalk leading to the abutment and gangway will be replaced in the same footprint,but raised in elevation to slope from 9.0 to 11.0 feet. The existing abutment and pier are elevated on piles above the underlying rip rap protected slope. The existing abutment is supported on a 6 ft wide by 2 ft long footing adjacent to the sidewalk,it is elevated above the slope for the remaining 11.5 feet in length. The replacement project will utilize a sloped gangway and somewhat larger abutment(6 ft wide by 6 ft long). The gangway will be elevated above the underlying rip rap slope,as is the existing pier. Accordingly,there will be little change to the existing slope other than minor shifting of a few square feet of rip rap slope protection for the removal of the piles and to allow for the new abutment that is 4 ft wider than the old abutment. The existing project structures that will be demolished are summarized as follows(the concrete ramp,upon which trailered boats are launched,is in good condition and will remain): Item Area(Square Feet) Elevation(FT-MLLW) Material Sidewalk 144(6'x 24') 9.0 Concrete Abutment 81 (6"x 13.5') 9.0-10.0 Concrete Pit, 243(6'x 40.5') 10.0-12.0 Concrete with metal railing Gangway 60(3'x 20') Water surface-12.0 Timber with metal railing Floating dock 180(6'x 30') Water Surface Timber deck,polyethylene floats, (2)-14 inch concrete guide piles The replacement facility will replace the pier and gangway with an 80 ft long gangway to improve universal accessibility to the floating dock. The replacement dock will be larger than the existing dock in order to serve multiple vessels that may need to moor at the facility during an emergency event. The characteristics of the new facility are summarized as follows(see also Figure 3): Item Area(Square Feet) Elevation(FT-NLLW) Material Sidewalk 210(7'x 30') 9.0-11.0 Concrete � t 42(7'x 6') 11.0 Concrete Gangway 480(6'x 80') Water surface-11.0 Aluminum Floating dock 800(10'x 80') Water Surface Composite with polyethylene or Concrete floats,(2)14-18 inch concrete guide piles In addition,the facility will include a security gate,installation of utilities(water and electric)from shore to the dock feeding utility pedestals on the new dock system. The construction activities include vibration removal of the eight(8)existing concrete guide piles, followed by hammering in the two(2)replacement piles.A barge-mounted pile driver and a land-based crane would be used to remove the existing piles,concrete pier and to install the gangway. The floating docks would arrive to the project site by truck,assembled and floated out from the existing ramp that Port of Redwood City Multi-Agency Maritime Facility 5 February 2010 Initial Study