3.5 Cultural Resources
On the north, the paleochannel may have experienced a low energy transition from fluvial to marsh
sediments. In the central and southern portions of the grid core data suggest that much of the sediment was
deposited in a high-energy intertidal environment.
The potential for occurrence and preservation of prehistoric archaeological sites within MB-1 is moderate.
This site spans a well documented paleochannel of the San Diego River. In the northern portion of MB-1
there is a low energy transition between fluvial and marsh sediments that would help to preserve prehistoric
materials contained in the fluvial sediments. In the southern portion of the grid, however, the potential for
site presence and preservation is reduced, given that most of the material in this region is intertidal, perhaps
a lagoonal entrance sand bar.
Historical Results
This proposed borrow site is situated near many historical features. In addition to the intentionally sunken
vessels located in Wreck Alley, at least three other types of subsea cultural features exist within the
immediate vicinity of MB-1. Artificial reef materials are positioned in several locations proximate to or
directly within MB-1. To date, this area holds 13,000 tons of concrete rubble or quarry rock. Plans call
for an additional 12,000 tons of material to be deposited on this site. Several side scan sonar targets
detected in this dredge area may be related to the artificial reef materials. The NOSC tower collapsed onto
the sea floor in 1986, and lies to the east near the proposed dredge area. In addition, the City of San
Diego and the San Diego Oceans Foundation are creating a new underwater park near the MB-1 site. The
Canadian destroyer Yukon will be the first dive site/ artificial reef within the proposed park. Older sunken
historic wreck sites reportedly exist down coast from the NOSC tower location.
There are three unidentified side scan sonar targets in the dredge area. They may be related to the material
deposited over time or they may be historic resources.
SS-1
At SS-1, the water depth varies from 40 feet along the eastern edge of the grid to 53 feet along the western
portion of the grid. A region within the northeast quadrant of area SS-1 has been designated as a source
site for sand dredging. At this site neither side scan sonar, nor seismic sub-bottom profiler lines were
collected for this study, however, side scan sonar and sub-bottom profiler data covering the SS-1 site were
Regional Beach Sand Project EIR/EA
Page 3.5-13
99-69\SANDAG EIREA 3.5 to 3.12.wpd 7/17/00
Previous Page
