Tidegates and Self-regulating Tidegates

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• Beach Nourishment
• Non-natal Nearshore Rearing of Salmon
• Natural Resource Damage Assessment
• River Delta Restoration
• Clean Water Act

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What Links To This Page?

• Topics ‎ (← links)
• Fisher Slough Restoration ‎ (← links)
• Self-regulating Tidegate (redirect page) ‎ (← links)
  • Smuggler's Slough Restoration ‎ (← links)
  • SRT (redirect page) ‎ (← links)
    • Samish Delta ‎ (← links)

Tidegates are typically one-way culvert placed under a levee or dike that separates freshwater and tidally influenced areas. It is designed to open and allow freshwater to drain to the sea during low tide, but to close at high tide.

Self-regulating Tidegates (SRTs) are a kind of tide gate technology that uses a float or another mechanism to detect water level, and delays closing of the tide gate until flood tide reaches a certain level. Compared to a standard tide gate or flood gate, a SRT maintains connectivity between the Salish Sea and tidal channels, purportedly improving water quality and access for estuarine dependent fish.

• Wikipedia article on Floodgates

Notes

• Lyons & Ramsey 2013 provides an analysis of the Tide gate effects analysis work completed by the NWFSC
• The Tidegate Fish Initiative in the Skagit Delta defines a negotiated agreement that balances the diking and drainage district interests in maintaining drainage infrastructure, and the federal interest (as administered by NOAA) in recovery of Chinook salmon under the Endangered Species Act.
• The following restoration efforts have used self-regulating tide gates:
  • Fisher Slough Restoration in the Skagit Delta
  • Fornsby Slough Restoration in the Skagit Delta
  • McElroy Slough Restoration in the Samish Delta
  • Smuggler's Slough Restoration in the Nooksack Delta
  • Edison Slough has been retrofitted with a SRT.