Estuary Transformed  

Government Island and tidal canalThe Oakland Estuary has been transformed to serve the needs of the cities at its shore. A channel, 5 feet deep at extreme low tide, was cut through the sand bar at its mouth in 1859. In 1877, the ship channel was deepened to 20 feet at high tide; by 1939 it had reached 35 feet at low tide; current dredging projects will deepen the channel to 42 feet. In 1901, the Army Corps of Engineers cut through the neck of land that connected Oakland and Alameda. Alameda became an island, separated from Oakland by the Tidal Canal. It is called the Tidal Canal because it was supposed create a tidal flow that would scour out the Estuary ship channel and minimize the continual need to dredge. However, the scouring action of the tides has never been effective in keeping the ship channel clear.

Deborah Cooper
Oakland Museum of California

Oakland Museum of California Logo  "Walk Along the Water"
  Oakland Museum of California, used with permission.

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Link to excavation photoImage of tidal canal excavation - Oakland History Room, Oakland Public Library


Link to 1856 estuary map1856 Map of estuary and landforms - United States Coast Guard

Google Maps current satellite image of estuary

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