Topanga Lagoon Restoration – Shoreline Morphology

Abstract The Topanga Lagoon Restoration project aims to expand the current Topanga Lagoon habitat area and return the lagoon toward its historic footprint, improve estuarine hydrologic function and water quality, enhance sea level rise and coastal erosion resilience, and integrate public and emergency access while not negatively affecting the quality of the Topanga Point surf break. Unintended negative consequences to the surrounding shoreline caused by the restoration efforts are of concern. To avoid these consequences, a shoreline morphology study is requested to further understand the effects of restoration alternatives. Two-dimensional hydrodynamics, waves, sediment transports, and morphological change numerical modeling were performed to investigate potential impacts on adjacent beaches and surf quality due to the restoration of Topanga Lagoon.