(a) Determination of the longshore transport characteristics of the 

 project site and adjacent coast and deficiency of material supply to the 

 problem area. 



(b) Determination of the composite average characteristics of 

 the existing beach material, or native sand, in the zone of active 

 littoral movement. 



(c) Evaluation and selection of borrow material for the initial beach 

 fill and periodic nourishment, including the determination of any extra 

 amount of borrow material required for placement based on the comparison 

 of the native beach sand and borrow material. 



(d) Determination of beach berm elevation and width. 



(e) Determination of wave-adjusted foreshore slopes. 



(f) Determination of beach-fill transition. 



(g) Determination of feeder-beach (stockpile) location. 



a . Direction of L ongshore Tran sport an d Deficiency of Supply . The methods 

 of determining the predominant direction of longshore transport are outlined 

 in Chapter 4, Section V. The deficiency of the material supply is the rate of 

 loss of beach material — the rate at which the material supply must be 

 increased to balance the transport by littoral forces to prevent net loss. If 

 no natural supply is available as downdrift from a major littoral barrier, the 

 net rate of longshore transport required will approximate the deficiency in 

 supply. A comparison of surveys of accreting or eroding areas over a long 

 period of time is the best method of estimating the longshore transport rate 

 (the nourishment required to maintain stability of the shore). Collecting 

 long-term survey data both before and after project construction is 

 recommended. When surveys suitable for volume measurements are unavailable, 

 approximations computed from changes in the shore position, as determined from 

 aerial photography or other suitable records, are often necessary. For such 

 computations, the relationship in which 1 square meter of change in heach 

 surface area equals 8 cubic meters of beach material (1 square foot of change 

 in beach surface area equals 1 cubic yard of beach material) appears to 

 provide acceptable values on exposed seacoasts. This relationship presumes 

 the active beach profile extends over a range in elevation of approximately 8 

 meters (27 feet). The relationship should be adjusted accordingly for shores 

 with greater or less extensive active beach profiles. 



b. Des cription of Native Beach Sand . It is first necessary to sample and 

 characterize native beach sand to obtain a standard for comparing the suita- 

 bility of potential borrow sediments. Native sediments constitute those beach 

 materials actively affected by beach processes during a suitable period of 

 time (1-year minimum). During a year, at least two sets of samples should be 

 collected from the surface of the active beach profile which extends from an 

 upper beach elevation of wave-dominated processes seaward to an offshore 

 depth or "seaward limit" of littoral sand movement. Ideally, a "winter" and 

 "summer" beach condition should be sampled. The textural properties of all 

 samples are then combined or averaged to form the native "composite" sample 

 which serves as the native beach textural standard. Textural properties of 



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