Beach nourishment alternative assessment to constrain cross-shore and longshore sediment transport

• A combined field and laboratory approach was chosen to investigate beach nourishment alternatives with structures.
• Different design alternatives were tested in laboratory to investigate their effect on the lifetime and evolution of a beach nourishment project.
• A methodology is presented to allow comparisons between the performances of each design, considering non-dimensional cost, benefit and lifetime.
• The results reveal nourishment performance of different design alternatives and a methodology is presented to allow quantitative comparisons.
• The methodology presented can be applied at other sites to compare performance of beach nourishment designs based on physical parameters.

A combined field and laboratory investigation was conducted to assess five options for creation of a recreational beach on a steep, armored shoreline on the eastern Black Sea coast. All designs incorporated a beach nourishment project placed between two existing, shore-normal, rubble-mound groins. Alternatives included the placement of a nearshore berm, longshore extensions added to the existing groins, and shore-parallel breakwaters. Several alternatives are reviewed for quantifying the performance of each design, including assessment of the change in shoreline position and project volume retained between the groins. Dimensionless benefits and benefit-cost ratios are quantified, and recommendations made on how to select the best outcome from a benefit-to-cost standpoint when options including hard structures are incorporated into a beach nourishment project design.