dredging events totaling some 24,803 cu yd (18,964 m3) was placed on the erod-
ing beach just south of the mainland beach rock revetment at Andrew Harding's
Lane. This placement is seen in Figure 24 as the white area on the beach just
south of Holway Street.
A proposed new channel orientation is also shown in magenta in Figure 54 for
dredging by the New England District in 2000. This channel is within the dredge
area maintained by Barnstable County (in yellow). This new channel orientation is
based on the recent evolution of the west ebb spit of the north flood shoal, where
the narrowest point to cut through the spit is in the orientation shown. This chan-
nel location is the same one used by the county, which has only had to dredge the
outer end to maintain access. With the possible breach of the flood shoal spillover
lobe and re-establishment of the west flood channel in its prebreach position and
possible detachment of the entire west side of the flood shoal, the most likely path
of a stable navigation channel for the next few years is on a northwest-southeast
orientation, through the western ebb spit area.
Dredged Volumes Relative to Inlet Volumes
Records of volumes of material dredged from the Aunt Lydia's Cove entrance
channel and anchorage in front of the Fish Pier are available since 1993. A com-
parison of the volume estimated to be contained in the north flood shoal was
compared with the volume of material dredged from the entrance channel and
anchorage over the study period (Figure 55a,b). For 1993, about 4.5 percent of the
material contained in the flood shoal at that time was dredged. The 1994/95
dredging by the New England District removed about 13.2 percent of the esti-
mated volume of the flood shoal that year. The three dredging operations of 1993
removed some 2.0 percent of the estimated volume of the 1993 flood shoal. In
1999, about 1.5 percent of the estimated flood shoal sand volume was removed.
From Table 5 a total of 170,553 cu yd (130,405 m3) have been documented to
have been dredged from the cove since 1993.
To assess what impacts the dredging may have had on the entire inlet system,
a compilation of the total estimated volume from all of the inlet morphologic
features was done over time. Figure 56 shows the cumulative total estimated
volume of each separate inlet feature through time. Comparison of the dredged
volumes with the total estimated volume of sand in each inlet feature indicates
that the 1993 dredging quantities were 0.36 percent of the inlet sediment volume.
The 1994/95 dredge quantity was 0.96 percent of the inlets volume of sand
located in the measured inlet features in 1995. The combined dredging in 1998
was 0.16 percent of the total inlet sand volume that year. The two dredging events
in 1999 accounted for 0.13 percent of the total inlet sand volume in 1999.
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Chapter 6 Dredging Plan Recommendations
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