Designing Replacement Tide Gates for Fish Passage in the Estuaries of the West Coast of the United States: A Heads Up for the Engineers

Tide gates are deleterious to fish habitats in the low lying lands of estuary systems. Landowners occasionally desire to repair or replace the broken tide gates.  Due to the cost of the repairs, the landowners often seek financial assistance from government agencies and watershed oversight groups. Fish management agencies often seek to take advantage of these opportunities to replace the old gates with new ones that provide fish passage and improve habitat. This presentation provides an overview of the types of background investigations and analyses that should be completed by natural resource specialists before the engineers are directed to design the replacement tide gates.  These investigations should address:  restoration goals; evaluation of habitat objectives; property ownership; coordination with landowners, local governments, and watershed councils; transition of plant communities from dry land vegetation to tidal marsh vegetation; hydrologic effects, and estuarine geomorphologic impacts.  We also discuss applicable tools such as remote sensing products, GIS and mapping services, and hydraulic models and how those tools can assist in the pre-design investigations.