Topography and Surface Water. Topography. The Long Beach Peninsula exhibits long and low parallel north-south dune ridges interspersed with shallow xxxxx. The following dune forms are found in this landscape: foredune, deflation plain, sand hummock, blowout, dune ridge, and swale. (Xxxxxxxxx, 1984) From west to east, first there is a broad and gradually sloping ocean beach. The foredune is a ridge of sand parallel to the ocean beach and located just above the limit of ordinary wave action. Behind the foredune is a low-lying deflation plain where interdunal wetlands form at surface elevations of 14 feet National Geodetic Vertical Datum of 1929 (NGVD29) or lower. To the east of the deflation plain is the historic foredune, a dune ridge. The foredune, deflation plain, and dune ridge comprise the city’s dune area, or dune complex, averaging about 2,000 feet in width. The ocean floor from the shore outward to approximately seven (7) miles is considered the inner (nearshore-shallow) continental shelf with a relatively flat slope and depths up to 131 feet. West of the inner shelf is the midshelf, an irregular band varying in width from seven (7) to 17 miles, also of a relatively flat slope and with depths of 131 to 656 feet. Beyond the midshelf is a the relatively narrow mesobenthal upper continental slope with depths of 656 to 2,297 feet, and finally is the bathybenthal lower to toe of the continental slope with depths of 2,297 to 11,500 feet. The substrate of the inner shelf is sand; the substrate of the midshelf and the mesobenthal is sand and mud with some rock outcropping; and the substrate of the bathybental is mud. (Washington Marine Spatial Planning, 2014) Surface Water. Long Beach is located within the Willapa Watershed, also termed Water Resources Inventory Area (WRIA) No. 24. No natural rivers or streams are located in Long Beach. The city has several stormwater outfalls to the ocean beach, located—from south to north—at 11th Street Southwest, 3rd Street Northwest, between 6th and 7th Streets Northwest, and at 12th Street Northwest. Under section 303(d) of the Clean Water Act, states, territories, and authorized tribes are required to develop lists of waters that do not meet water quality standards set by states, territories, or authorized tribes. Currently, there are no identified 303(d) terrestrial waters located in Long Beach or near enough to be affected by activities in the city’s shoreline jurisdiction. (Ecology, 2014) Ocean waters off the shore of Long Beach are co...
