Association of State Wetland Managers - Protecting the Nation's Wetlands.

The Compleat Wetlander: Publications Available to Support Community Decision Making to Minimize Flood Risks

cwlogoBy Jeanne Christie, Executive Director, ASWM

The recent flood in Louisiana has moved off the front page of the news in many areas of the country.  But recovery is just beginning for the people and communities where 150,000 homes were damaged by the flood.  An estimated 80% of these homes lacked flood insurance.  The price tag for recovery could reach $15 billion.  If so, it would be one of the costliest natural disasters in U.S. history.  For those of us who live far away from where the flooding occurred, it’s difficult to comprehend the extent of the flooding as well as the grief and exhaustion and hard work ahead for the people trying to recover.

In the wake of the flooding there have been a number of news stories describing how warmer air and water temperatures that are being recorded worldwide are likely to lead to more intense and frequent rainstorms.

There are opportunities to provide aid.  Some will donate money or supplies; some will assist with the recovery efforts.  Others will begin thinking about how to support actions to reduce the extent of the impact caused by such events in the future.

To do this, it is necessary to assess the usefulness of some of the tools that are available.  One tool that is extensively used is floodplain maps that identify areas at risk for flooding.  As noted above, the majority of flooded buildings were owned by people who had not purchased flood insurance.  Many were not in the floodplain. In fact according to a story in The Advocate, just three weeks before the flood, about 2,000 homes in the town of Central LA received letters letting them know they were no longer required to purchase flood insurance.  According to the story, the change was expected to save residents $2 million a year in flood insurance premiums.

legalissuesjon0416A number of risk-averse communities around the country are likely to take another look at flood insurance and floodplain maps and try to assess their options.  A starting point for understanding how the courts have treated floodplain mapping, both Federal Emergency Management Agency (FEMA) flood insurance maps, maps that anticipate climate change impact, a new publication by ASWM Associate Director Emeritus, Jon Kusler may prove useful.  Legal Issues in Upgrading Flood Maps to Reflect climate change, Other Changed Conditions provides information about some of the different kinds of floodplain maps that have been completed around the country and cites court cases that have addressed challenges to different basis for developing floodplain maps.  At the end of the nine-page document there are five recommendations for avoiding problems with flood mapping procedures and flood maps that incorporate climate change or other changed conditions:

  1. Follow statutory and ordinances procedures and other requirements.
  2. Incorporate the best information available.
  3. Over time, develop increasingly specific and quantified flood maps reflecting climate change and other changes in floodplain hydrology and hydraulics.
  4. Provide procedures for updating or making more specific flood elevations, velocities, erosive forces and other flood factors on a case-by-case basis.
  5. Request the legislature to endorse the maps and fact finding upon which the maps are based.

As the report points out, there are uncertainties in mapping floodplains.  So it is logical that risk averse communities will want to take action beyond proactive mapping of the floodplain. This may take a number of forms such as participating in FEMA’s Community Rating System (CRS)  which is a voluntary incentive program which encourages communities to take actions that exceed minimum National Flood Insurance Program requirements by reducing flood insurance premium rates for residents in communities by up to 45% by achieving the three goals of CRS.

  1. Reduce flood damage to insurable property;
  2. Strengthen and support the insurance aspects of the NFIP, and
  3. Encourage a comprehensive approach to floodplain management.

definitonsreportjon0416Protecting natural floodplains as open space and preserving and restoring natural shorelines are among the activities that can contribute to reducing flood insurance rates.  Flood storage is one of many benefits of restoring and protecting floodplains, shorelines and wetlands.  Another recent ASWM publication: Definition of Wetland, Floodplain, Riparian “Functions” and “Values” provides an overview of how the terminology and methods are used to identify and quantify the functions and values of these resources as well as some of the inherent strengths and weaknesses of different approaches.  The publication includes floodplain storage as a value/function of these aquatic systems. It highlights the importance of understanding what aspects of flood retention and storage are considered by various methods and which ones are ignored. It also describes a much larger suite of scientific and societal benefits derived from these resources as well as the importance of location. For example, a wetland/floodplain in or upstream of a town can provide substantive flood storage so that waters don’t flood residences.  However, if the floodplain is developed and the ‘storage’ replaced at a different location, it will no longer be located where it will reduce flood risks in that area.

The flooding in Louisiana this summer was unprecedented.  Communities will need to decide whether to ignore it because it is something that will not happen again, or as a harbinger of future challenges.  Following superstorm Sandy, the U.S. Army Corps published North Atlantic Coast Comprehensive Study: Resilient Adaptation to Increasing Risk: Emergency Costs (January 2015).

The resources described above and many others are available to allow communities to evaluate risks, weigh options, and move forward with plans to protect the health, safety and property of their residents.


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