MetOcean, Wave and Sediment Transport Engineering Study
Lally Consulting LLC (Lally LLC) was contracted to conduct wave and sediment transport studies in support of development of several shoreline restoration projects in Washington State.
Field data collection, analyses and synthesis were carried out by Lally LLC’s coastal engineering personnel in order to establish relevant site hydrodynamic forces and other parameters to engineer long‐term, nature-based coastal resiliency solutions. Work included:
- MetOcean Data Acquisition and Analyses. Lally personnel collected historical water surface elevation data and conducted analyses to determine potential future water elevation rise. Hindcast wind data sets were acquired from multiple government and municipal sources, with quality assurance and statistical analyses performed to develop several recurrence interval and wind spectra data sets.
- ADCP Deployment. Lally LLC engineer-diver personnel implemented a field data acquisition program for needed oceanographic data through seasonal deployments of an Acoustic Doppler Current Profiler (ADCP) with waves array. A 1200 kHz TRDI Workhorse ADCP was deployed and retrieved via SCUBA and lift bag to yield empirical wave and currents data through a full storm season.
- Wave Analyses. Wave data acquired through the ADCP campaign was used to develop wave height, wave period and other critical characteristics based on site wind spectra and recurrence interval storm winds. We further evaluated compounding wave forces including reflected wind waves, wave transition from deep to shallow water, and vessel wakes.
- Hydrodynamic Modeling. 1D and 2D numerical modeling (ADCIRC) was conducted for the prediction of recurrence interval wave parameters, wave transformation, wave runup, gross and net littoral sediment transport rates for varying shoreline / nearshore geometries, coastal structures and recurrence interval wave conditions. Project sediment budgets were also determined using this data.
- Engineering Design. Lally LLC engineered long‐term shoreline erosion control and dredging management solutions, from conceptual through final designs, in order to achieve dynamic stability of coastal, riverine and lacustrine shoreline and nearshore sites based on the wave and sediment transport studies. Individual projects included a private beach restoration, nearshore habitat enhancement, and maintenance dredging plan for a boat basin. Associated maintenance and adaptive management plans were also developed as part of this work.
We authored a peer-reviewed Wave and Sediment Transport Study as part of the permit application process which supported multiple permit acquisitions, and has since been requested by federal, state, tribal, consultants and other stakeholders for planning and design of other shoreline management and aquatic restoration sites in the region.
Services Provided
MetOcean Data Acquisition and Analyses
Multiple Acoustic Doppler Current Profiler (ADCP) Deployments
Wave and Coastal Structures Modeling
Calculation of Sediment Budgets
Berth Maintenance Dredge Plan
Vessel Wake Analysis
Location
Washington State, USA