Tidal Channel Restoration Guidelines

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This project is addressing the lack of tidal channel reference data to efficiently design restoration of barrier embayments in Puget Sound. This project is systematically inventorying the tidal channel geometry of intact barrier embayments, collecting field data from a subset of these barrier embayment systems, and conducting a regression analysis to determine the best predictor of channel geometry. The project outcome will be guidelines for appropriately sizing tidal channels for restoration projects based on empirically derived models which describe the relationship between channel geometry, marsh area, and tidal prism.


  • Data collection for the study began in 2017. Topographic/bathymetric and discharge data were collected at 7 locations across Puget Sound.
  • Desktop data analysis was completed between 2018 and 2019.
  • In 2019 a large number of sites were visited and topographic data only was collected, these site visits were used to determine final sites for data collection in 2020.
  • In 2020 Topographic/bathymetric and discharge data were collected at an additional 4 locations around Puget Sound.

Related Materials


  • PSNERP tidal channel restoration guidelines were based on studies in San Francisco Bay.
  • San Francisco Bay data are not fully applicable to Puget Sound. Tidal channels in Puget Sound have different geometry than channels in San Francisco Bay due to different sedimentparticles of clay, silt, sand, gravel, or cobble, transported by water, are called sediment. composition, larger tide ranges, greater rainfall, and salinity distribution and plants (Hood 2007,Hood 2002).
  • Studies on the geographic variation of tidal channel geometry in Puget Sound have shown that tidal channel geometry might be better predicted by tide range than tidal prism (Hood 2015).
  • Tidal channel data will be used to conduct a regression analysis and develop hydraulic geometry scaling relationships.
  • The goal of the study will be to develop one set of regression lines for the Puget Sound basin; however, if the data collection reveals important differences between sub-basins, then two or more regressions may be developed.

Partners and Roles


  • Develop project plan (Complete)
  • Develop Wiki pages (Ongoing)
  • Conduct Desktop Inventory of Barrier Embayments in Puget Sound (Complete)
  • Conduct Field Inventory of Barrier Embayments (Complete)
  • Conduct Interim Results Analysis (In Progress)
  • Convene technical advisory group (Two TAG meetings complete, one more after draft final results)
  • Author final project report (Winter 2020-Spring 2021)
  • Final project presentation (June 2020)