emplacement and removal, and the pipe lengths. Profiles are numbered in 

 this paper according to CERC's numbering system designed for computer 

 usage. The correspondence between CERC's profile numbers and the profile 

 identification used by the surveyors in the field is shown in columns 

 2 and 3 of Table I. Pipes are numbered in this paper consecutively from 

 the land towards the sea. 



It was necessary to request permission from local authorities to 

 place the pipes on the beaches. Permission was granted in all cases, 

 usually subject to the condition that the pipes be removed before the 

 summer tourist season. Unpaid local observers (Table I), enlisted by the 

 New York and Philadelphia Districts, observed the sand levels on the pipes 

 at approximately 1-week intervals. These observations were recorded on 

 forms (Figure 2) which were mailed weekly to CERC. At CERC, the sand 

 elevations with respect to the pipes were converted to elevations above 

 MSL, using a template overlay on the form. 



To check accuracy of the method, reduced values of the observed 

 sand elevations on each pipe profile were plotted against elevations 

 obtained by normal surveying methods on the same profile for the' same 

 date (Figures 3 and 4). Agreement between surveys and sand levels ob- 

 served on the pipes was good on the New Jersey beaches (Figure 3) and 

 Westhampton Beach, but was questionable on Jones Beach (Figure 4). No 

 explanation is available for the lack of agreement shown at profile 07 on 

 Jones Beach, in Figure 4. Although sand levels at the pipes on profile 11 

 of Jones Beach agree well with the survey, the 50-foot pipe spacing on a 

 steep beach gives a poor indication of the surveyed sand levels between 

 the pipes (Figure 4 ) . 



4. Period Covered 



The main period of interest for this report is the 3-month 

 interval from January through March 1968. However, the earliest pipe 

 range survey was on 17 November 1967, at Jones Beach. Before summer 

 1968, the pipes were removed from Long Beach Island, Atlantic City, and 

 Jones Beach. Readings continued all year at Westhampton Beach, but were 

 discontinued at Ludlam Island, although most of the pipes remained in 

 place there. 



The time interval between successive observations of sand levels on 

 the pipes are referred to as "1-week" intervals. Actually, although most 

 readings were taken at 7-day intervals, the interval between observations 

 ranged from 3 days to 3 weeks. The exact time intervals are in Appendix A. 



