NWF Report: Global Warming and Flooding

Connecting the Dots: Midwest Flooding, Global Warming, Floodplain (Mis)Management, & National Legislation
Increased Flooding Risk Demands Better Choices to Manage Flood-Prone Areas

Washington, DC (July 9) – The United States is getting more heavy storms and major floods these days, detailed in a new report from the National Wildlife Federation.

Full Report: NWF Flood Report

“Global warming is partly to blame for these heavy rainfall events,” said Dr. Amanda Staudt, climate scientist, National Wildlife Federation. “Warmer air simply can hold more moisture, so heavier precipitation is expected in the years to come.”
To explain the bigger picture and provide recommendations for how to cope with projected changes and how to avoid the worst impacts of global warming, National Wildlife Federation’s mini-report Increased Flooding Risk: Global Warming’s Wake-Up Call for Riverfront Communities details:

• How global warming has caused more heavy rainfall events
• America’s over-reliance on levees and other strategies for taming rivers
• Communities that are on the front lines
• What must be done to confront the realities of global warming

In the Midwest and Northeast, big storms that historically would only be seen once every 20 years are projected to happen as much as every 4 to 6 years by the end of the 21st century. At the same time, shifts in snowfall patterns, the onset of spring, and river-ice melting may all exacerbate flooding risks. In the Pacific Northwest, snow melt discharge occurs 5 to 20 days earlier than it did 50 years ago, and it could be an additional 30 to 40 days earlier by the end of the 21st century if global warming pollution is not curbed.

The last year has been no exception:

• In June 2008, the rain-swollen Cedar, Illinois, Missouri and Mississippi Rivers and their tributaries topped their banks and levees, leaving hundreds of thousands of people displaced across the Midwest. Over $15 billion of agricultural and property losses were racked up and 24 people lost their lives.
• In January 2009, floods in the Pacific Northwest caused $125 million of damage, evacuations of more than 30,000 people, and shutdown of major roads and rail service.
• And, March brought record-high levels to the Red River bordering North Dakota and Minnesota, following an unusually wet fall and winter. Fargo narrowly averted a major disaster through a massive effort to build temporary sandbag levees and to evacuate thousands of people.

Many of our attempts to control rivers and our choices to live and farm in floodplains only serve to compound the risk of flood-related damages. The realization that the future will bring more flooding risk means that we need to make better choices about how we manage the landscape in flood-prone areas.
Grand Forks, North Dakota has done just that. Following devastating floods in 1997, the city took the bold action of buying out hundreds of properties in the floodplain and converting the land to parks, public recreation and habitat areas. They installed new grass covered levees and removable flood walls well back from the river’s edge, thereby allowing more space for the river to swell as it would under natural conditions. Grand Forks has absolutely reaped the benefits of these investments. None of the major floods in recent years have caused significant damages to the city.
“Now is the time to confront the realities of global warming, including the increasing frequency and intensity of heavy rainfall events across the country,” said Dr. Staudt. “We must aggressively move toward a cleaner energy future and reduce global warming pollution, thereby ensuring that we avoid the worst impacts.”
Important steps to reduce the risks to riverfront communities include discouraging development in flood-prone areas and protecting the natural systems, such as wetlands, that help to buffer against floods.