Net Shore-Drift Mapping

Problem: Incomplete Net Shore-Drift Mapping

Long-term littoral drift, or net shore-drift, is the slow movement of beach sediment alongshore by waves and currents. Understanding of historical and current net shore-drift is essential for interpreting beach geomorphic change, for determining the most appropriate actions at specific sites, and for management of forage fish spawning and other beach habitat areas.


The CGS Solution

In 1992, Jim Johannessen of CGS originally mapped 500 miles of Puget Sound shores for the Washington State Department of Ecology. This was expanded, revised, and updated through several subsequent CGS projects. These efforts included mapping historical net shore-drift for the US Army Corps of Engineers in 2007, and most recently in 2017.



Net shore-drift mapping provides the framework for all coastal process assessments in the region. These data have formed the basis for CGS work on the Puget Sound Nearshore Ecosystem Restoration Project (PSNERP) and Beach Strategies. Corrected digital mapping of net shore-drift has enabled restoration prioritization throughout the region.


More Regional Assessment Case Studies

Click on each image below to learn more about CGS regional assessment projects.

Completing net shore-drift mapping in the Puget Sound
Feeder Bluff Mapping of the Puget Sound
Assessing risk to utility cable landing, Blakely Island, San Juan County