Blog: The floodplain forward – Bypasses and fish habitat
Today, 95% of the Central Valley’s historical floodplains are cut off from the river by levees. Built in the early 1900s to combat devastating floods, levees and bypasses were constructed to corral mighty rivers and push water quickly through the system. Even before invasive species, large rim dams, and Delta water export facilities were introduced into the system, salmon populations started to dramatically decline with the construction of the levees. Simply put, the levees prevented Chinook salmon from accessing their primary food source.