Figure 4. Cross-section view through the Jupiter Carlin Beach Nourishment Project borrow site.

This cross section indicates that Area #1 is to be dredged to -72 feet NGVD (National Geodetic Vertical Data, developed in 1929 as a measure of sea level) and Area #2 to -71 feet NGVD. The 1-foot allowable overdraft (indicated at the left) in an allowance granted to dredging contractors because of the imprecision that is inherent in this work; contractos are generally paid based on the quantity of material that is dredged, based on a comparison of a pre and post-dredging surveys. JC-11 and JC-14 are locations where vibracore samples were taken. SM, SP, GM, and ML are classes of materials -- silty sand, clean sand, silty gravel, and silt, respectively.