Crisis Averted: The 2007 Montpelier Ice-Up
A Disaster Preparedness Success Story
A lot of luck and a little wastewater and sand turned out to be a recipe for success. Despite our worst fears of a repeat of the 1992 flood, the city of Montpelier, Vermont escaped the "great ice-up" of 2007 unscathed.
When the Winooski River froze solid in January the threat of flooding was immediately apparent - and plans for the flood fight commenced. The city began meeting with Vermont Emergency Management (VEM) almost immediately and the group eventually grew to include other state and federal agencies. Those other resources included the Cold Regions Research and Engineering Laboratory (CRREL) in Hanover that is run by the Army Corps of Engineers; the National Weather Service (NWS); the U.S. Geological Survey (USGS); the Civil Air Patrol (CAP); the Federal Emergency Management Agency (FEMA); the Vermont National Guard; the Vermont Agency of Natural Resources; The Vermont Agency of Transportation; the Vermont State Police; and the Colchester Technical Rescue Team.
CRREL assessed the condition of the river and installed gages that would monitor the water level on the river (15 feet is flood stage in Montpelier, and the gages never went much above 10 feet.) CRREL also determined ice thickness and channel width at various times throughout February and March. These measurements helped us understand what the river was doing, and more importantly, what it might do in the future.
Two strategies were developed based on this information. One was to "dust" the ice with a dark organic material in an effort to attract the sun, heat the ice, and if not melt it away, at least weaken those sections so channels could eventually be created. The other was to pump water from fire hydrants into the river, and to divert treated wastewater that normally enters the river downstream a bit farther upstream; both water sources were warmer than the river and the hope was they too would create channels where ice could eventually travel during a thaw.
Despite these efforts, it seemed that a flood in Montpelier was more a question of when rather than if, so the city and state took steps to prepare for the worst-case scenario. Evacuation maps with tips on what to do before, during, and after a flood were developed and distributed to an eager public, many of whom started to plan accordingly. Businesses removed inventory from basements and low-lying areas and held pre-flood sales. The people of Montpelier reacted rationally and appropriately in the face of this threat, which made preparations go smoothly.
Sandbags were a key component of those preparations and that effort was given a boost by the Vermont National Guard. Volunteer Guard members came to town on a Tuesday and worked hard through sometimes adverse conditions (including rain and a small flood where they worked) and in four days more than filled the needs of city residents and businesses with more than 5,000 filled sandbags. While eventually not needed, the city now has those sandbags stored for future use.
The lack of a flood is due largely to the one factor none of us could control - the weather. Despite some tense moments on March 15-16, when warm weather and rain caused other rivers to flood and made the ice in Montpelier start to crack, the Winooski stayed below flood stage and eventually receded and re-froze during a cold spell. After that, the warm days, cool nights, and lack of rain made for perfect conditions to evenly and slowly weaken and break up the ice.
This is not to say mitigation efforts were fruitless; the channels that had been created by wastewater and sections dusted and weakened by the sun gave the ice upstream an avenue to exit the city without jamming and flooding Montpelier. They were simple, unspectacular methods that proved successful.
This event showed how disaster preparation is supposed to work; through cooperation at all levels - from the highest reaches of government, to individuals planning their family's evacuation, to volunteers helping to fill sandbags, to the Times-Argus, the local newspaper, which printed daily updates informing the public of current conditions on the river. We hope not to have a repeat of this anywhere in Vermont anytime soon, but if we do, we have a sound model to follow courtesy of the city of Montpelier.
This article appears courtesy of Vermont Emergency Management.
Last Modified: Tuesday, 26-Feb-2008 11:53:51 EST