Rodger Olson and Kevin Campbell, Fargo, letter: Diversion renders Fargo's risk manageable
FARGO -- There is some confusion these days over how much flood risk reduction the Fargo-Moorhead Metro Area Flood Diversion Project would provide. We would like to clarify.
Herald readers probably have heard public comments over the past few years saying the diversion would give us protection against a 500-year flood.
But based on the plan put forth in the final feasibility study, the diversion project is intended to provide 100-year flood level of risk reduction.
This means that with the diversion project in place, the communities of Fargo and Moorhead would need only very minor emergency protection measures during a 100-year flood event.
A 100-year flood event is now estimated at 42.4 feet, based on the 2010 findings from an expert panel of scientists and hydrologists formed by the US Army Corps of Engineers.
The changed definition of flood levels in Fargo is a result of changing hydrologic conditions and is not caused by the proposed diversion project.
The panel concluded that the current wet cycle has changed the definition of flood events such that the flood of record in 2009 is now estimated to be equivalent to a 50-year flood with a crest of 40.8 feet.
While the diversion project provides 100-year flood level of protection, it also gives us a fighting chance at protecting ourselves from a 500-year flood.
But that's true only when the diversion is combined with emergency flood fighting measures throughout our cities, such as the clay and sandbag dikes that had to be built during the 2009 flood fight.
The permanent dikes and levees now being built in Fargo-Moorhead and in Cass and Clay Counties will complement the diversion project to reduce our flood risk from events larger than a 100-year flood.
Without the diversion project, we likely could not win a fight against a 100-year or larger flood.
The 2009 flood, the worst flood we've ever fought, was approximately a 50-year event.
It took everything we had, and scores of volunteers from all around to "win" that battle.
Even at that, we came closer to losing our fight than most people realize.
Our community would not be dry and thriving like it is today without the efforts of thousands of people who exhausted themselves to save our communities.
The emergency flood fighting measures used in 2009 and previous floods should not be considered reliable for future flood fights. Emergency levees can fail, dikes can breach, and people can succumb to exhaustion.
The diversion project is absolutely needed if we are to survive the kind of flooding that is possible in the F-M Metro Area.
Rodger Olson and Kevin Campbell
Olson is chairman of the Public Outreach Committee of the Flood Diversion Board of Authority. Campbell also is a member of the both the authority and the committee.