Flood Protection is Topic of Conversation in Virginia and California

On Wednesday, March 11th two of my NRDC colleagues, Joel Scata and Ben Chou, will be attending listening sessions on the updated federal flood protection standards that President Obama put in place with his January 30th executive order. Joel will be atten

On Wednesday, March 11 two of my NRDC colleagues, Joel Scata and Ben Chou, will be attending listening sessions on the updated federal flood protection standards that President Obama wisely put in place with his January 30th executive order.

With our climate and precipitation patterns changing, floods become much more likely than previously understood. That's why it's so important to ensure that when the federal government funds bridges, roads, schools, water treatment systems, and other critical infrastructure, they ensure that these facilities are built to a more protective standard.

Joel will be attending the meeting in Norfolk, Virginia while Ben will be at the meeting in Mather, California. Neither state is a stranger to floods.

Virginia experiences flood risks from every imaginable angle. Flash floods can affect small streams in the mountainous western part of the state, while the larger rivers in the eastern portion of the state experience larger flooding. But the scariest flood risks may be those associated with sea level rise. Virginia's coastline is experiencing some of the fastest rates of sea level rise in the world. This is particularly bad news for the U.S. Navy, since the largest base it owns on the planet is located in Norfolk, so in a very real sense, sea level rise and future flood risk have national security implications.

While drought is the main problem on the minds of Californians these days, floods are still an all-too regular occurrence. According to the state's disaster preparedness plan (also known as a hazard mitigation plan), there were 49 federal disasters declared in California for flood-related disasters alone between the years 1954 and 2011. And the state has a lot at risk from future floods. More than $575 billion worth of property is located in areas defined by the 500-year floodplain. One in five Californians lives within the 500-year floodplain, either along the state's long coastline or its rivers, many of which tend to be flashy, high-gradient streams susceptible to flash floods.

The new standard is a big improvement. It gives federal agencies the flexibility of selecting one of three benchmarks when evaluating project designs or deciding whether to fund public infrastructure projects: elevating infrastructure based on a projection of how much higher flood elevations may rise in response to climate change; the 100-year flood level plus at least two additional feet of elevation; or the 500-year flood level.

Reliance on the current 100-year flood elevation as the standard is predicated on two faulty assumptions.

First is the assumption that flood frequency projections made by the U.S. Army Corps of Engineers and FEMA mirror reality. In fact, these projections often underestimate the true risk of flooding. One study found the 100-year flood stage calculated for Hannibal, Mo. - Mark Twain's historical Mississippi River hometown - should more realistically be defined as the 10-year flood stage. Researchers at University of Iowa recently published a study that found floods are occurring with increasing frequency throughout the Midwest, confirming what most of us already realized -- that floods are happening more often.

Second, the way flood frequencies and elevations are calculated is based exclusively on past historical experience and our present knowledge of land use and hydrology. No accounting is made for future conditions, particularly those conditions that will arise in response to climate change. Currently, FEMA's flood maps and the Corps' projections of flood elevations fail to take into account the likelihood of more frequent extreme precipitation events, future sea level rise on our nation's coasts, and other conditions that may contribute to floods being more likely or more severe.

Critics wrongly claim that the new standards will raise premiums for the National Flood Insurance Program and will dramatically increase the costs of public projects -- but they're wrong. The new standards should have no impacts on how flood insurance premiums are calculated. And as far as project costs go, it's often far cheaper to either build outside the floodplain or build to a higher level of protection, than to rebuild a school, water treatment plant, or bridge that's damaged repeatedly by flooding.

The new standards will require federal agencies to use a more conservative estimate of flood risk when making decisions about what to build, where to build, and which local and state projects receive federal funding.

This is exactly what we need. Climate change is dramatically increasing flood risks, and it's time we help communities in Virginia, California, and beyond prepare.

Image Franklin, Va., September 22, 1999 -- Aerial view of flooded downtown Franklin, VA, shows oil contamination resulting from propane tanks and cars under water. Photo by: Liz Roll/ FEMA News Photo