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PRINCIPLES OF FLOOD MANAGEMENT AND FLOODPLAIN RESTORATION

In early 1997, partly in response to the New Year's floods in California, a group of 15 different environmental and fishing groups formulated a series of principles based on the scientific understanding of riverine processes and the repeated lessons gathered from disastrous flood evens around the nation:

1. Restore river systems and functions that improve hood management while also bolstering the effectiveness of existing hood control systems:

  1. Restore to a meaningful extent the historic capacity of rivers and their foodplains to better accommodate flood waters by setting back levees to widen the floodway (the river channel during high flood flows).
  2. Increase wetland and riverside forest habitat within the widened river zone.
  3. Increase the use of planned floodplain flooding to reduce downstream flood peaks.
  4. Strengthen existing, properly sited: but vulnerable levees, which protect high value floodplain uses that cannot be relocated of the floodplain.
  5. Reassess: the operations of reservoirs and waterworks to ensure the efficient, reliable and prudent use of flood control space. In some Cases, dams and waterworks need to be structurally modified to improve their ability to release water to avoid downstream flooding.
  6. Improve use of weather forecasting and monitoring of upstream conditions to have a better "early warning system" for when a flood could be coming.

 

2. Better manage the uses of floodplains to minimize taxpayer expense and maximize environmental health:

  1. Eliminate incentives or subsidies for development in the most dangerous parts of the floodplain. No more people shouls be put in harmís way.
  2. Reform floodplain mapping programs so that they accurately portray the risks and consequences of anticipated flooding. Ensure that Californianís understand that they are located in a floodplain.
  3. Ensure that new structures unavoidably being built in floodplains are designed to resist damage from foreseeable future floods.
  4. Educate Californianís on the risks of living, working, or farming in areas prone to floods  and make sure that they are willing to bear the appropriate financial responsibility for such use.
  5. Endeavor to relocate the most threatened Californianís and communities who volunteer to move to safer locations.
  6. Ensure the state and local governments responsible for floodplain land use bear an increase financial responsibility for flood recovery efforts.

3. Manage the entire watershed to provide the most protection from floods in an environmentally-sensitive way.

  1. Discourage development in remaining wetlands and floodplains. Wetlands and floodplains act as giant sponges which absorb and slow the progress of floodwaters.
  2. Use acquisition and easement programs to restore some of Californiaís historic wetlands and floodplain acreage and to promote functional restoration of associated river systems.
  3. Discourage clearcutting and road building in areas prone to mudslides.
  4. Where possible, replace non-native hillside annual vegetation with native perennials to improve rainwater absorption and reduce hillside erosion.

ďThe principles of floodplain management are now well known. Thereís no silver bullet. What you need is people willing to come to grips with the problem honestly. And now is the time to come to grips with it, because the half-life of memories of floods is very short.Ē

Brig. Gen. Gerald Galloway (retired) Chair, Interagency Floodplain Management Review Committee

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