Figure 59. Evolution of Aunt Lydia's Cove entrance channel 1990-1994
landward end of the north ebb channel, the elongated south ebb channel and the
east and west flood channels. This scour hole was present on a field survey in the
summer of 1999 and was located immediately off the edge of the mainland shore
rock revetment. The westward growth of the north beach spit has also narrowed
Chatham Harbor in this area. The entire tidal prism for Pleasant Bay has been
forced through this narrowing area, which has increased the tidal velocities. Tidal
currents from all four channels meet in this area, along with waves entering the
inlet throat, and most likely create a turbulent flow condition during parts of the
tidal cycle. This scour hole needs to be monitored to assess any erosion of the bed
89
Chapter 7 Conclusions