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The North Delta Flood Control and Ecosystem Restoration Project is committed to basing proposed improvements on the best possible science. Staff is identifying critical uncertainties that will affect the project alternatives including:


  • Will mercury methylation in restored wetlands result in unacceptable risk levels to the environment and public health?
  • What management practices (including restoration locations) might reduce rates of mercury methylation or be at lower risk of mercury methylation?


  • How can restoration such as dendritic tidal wetlands be designed to discourage exotic species use?


  • What are the potential sediment accretion and erosion rates in the project area and how will these rates affect ecosystem restoration and flood control design?
  • How can existing sedimentation processes be modified to enhance ecosystem restoration and flood control?
  • How will sedimentation processes affect geomorphic changes in wetlands and other restoration?


  • Does current hydrology and sedimentation support the creation and maintenance of a dendritic channel system in the North Delta area?

North Delta Planning staff is working to identify and address these uncertainties by conducting pilot projects and studies and through coordination with other research groups. Some examples of ongoing work regarding these critical uncertainties are: CALFED-funded research into mercury methylation at wetland restoration sites, a strategy to maintain adequate flows and periodic tidal drying to minimize exotic warmwater fish habitat, sediment transport modeling. Uncertainties that cannot be resolved prior to project implementation will be addressed through adaptive management during project implementation. The project schedule shows how the process for managing key scientific uncertainties is integrated with the North Delta EIR/EIS schedule.