Effect of Water-Table Manipulation on Beach Profiles

Abstract

The experimental study of the effects of water-table manipulation on beach erosion/accretion is meant to help engineers design and operate beach drain systems. The initial position of the drain and expected flow rates through the drain system are key design parameters. Whether or not drain systems can be used in both nontidal and tidal coastlines is discussed. The effectiveness of the drain for a range of wave climates is also addressed. The model study identified an important scale effect pertaining to the infiltration characteristics of the model beach face, which reduced the effectiveness of the model drain. The drain was effective for both accretive and slightly erosive wave climates and for both tidal and nontidal situations; the beach face steepens with the drain operating compared to the no-drain situation. This indicates that a drain system should be operated under a wide spectrum of wave conditions. Drain flow rates are dependent on wave climate and relative position of the drain.