Channel elevations for 3 July 1937 are shown in Figure 4-21a. The areal
extent of the flood shoal at this time is shown in Figure 4-21b, and channel
elevation change between 4 May 1936 and 3 July 1937 is plotted in Figure 4-21c.
For this 14-month period, the net volume change for the study area was
calculated to be 12,000 cu yd, yielding an annual sediment accumulation rate of
10,500 cu yd/year. The portion of the Federal navigation channel considered was
calculated to have 5,200 cu yd of infilling, for an average channel infilling rate of
4,500 cu yd/year for the period. The area of the Federal navigation channel
considered is 194,000 sq ft. The average depth of the channel for 3 July 1937
was calculated to be 7.8 ft. The flood shoal was calculated to have grown from
25,200 to 35,600 cu yd.
Figure 4-21a. Mattituck Inlet channel elevation, 3 July 1937
Chapter 4 Morphology Change, and Channel Shoaling and Migration