It’s Flood Season: Spring Flood Potential Starting out Normal
March 7, 2013
Sequestration Potentially to Affect Stream Gage Network
AUGUSTA, MAINE — With stream flows and snowpack within typical ranges and somewhat less river ice than usual, spring flood potential is normal for the time of year as “flood season” begins. The Maine River Flow Advisory Commission, meeting today in Augusta, reviewed information on current hydrologic conditions across the state, as well as short-term weather forecasts. However, the Commission also learned of potential changes in the state’s stream gage network because of budget cuts brought about by sequestration.
Robert Lent, Director of the Maine Office of the USGS New England Water Science Center and co-chair of the Commission advised the group that federal budget cuts due to sequestration could cause his office to discontinue a number of stream gages, between 7 and 12 sites (out of approximately 70 the agency currently maintains). Gage shutdowns would likely be in effect from April 1 until at least October 1, and possibly beyond. The data collected by the stream gage network is critical to accurate flood forecasting; however Lent said no gages necessary to flood forecasting will be discontinued during spring flood season.
Lent stressed that the stream gage network supplies critical data to a number of cooperating agencies, communities and industries. “All of these gages are important, for scientific or environmental reasons in addition to flood forecasting,” he said. Lent and his staff, along with MEMA, will be working with cooperators in the next few weeks to determine a final plan if gage shutdown is necessary. The USGS will be posting online(by Monday the 11th) a list of threatened gages online.
With regard to this year’s flood risk, Lent pointed out that “normal” does not mean “no risk”. “Spring in Maine always brings an elevated risk of flooding. As long as there is significant snowpack in the headwaters of Maine’s rivers, flood potential is much higher than it would be in the summer or fall. But at this point we don’t have any unusually high risk factors for the time of year.”
“Today’s conditions are a snapshot for today. Everyone should stay aware of current forecasts,” according to Rob McAleer, Director of the Maine Emergency Management Agency, and co-chair of the Commission. “It looks like conditions will be stable for at least the next couple of weeks. But one rainstorm at the wrong time could cause major flooding.”
The National Weather Service noted that for the next two weeks, temperatures are expected to be slightly below normal, and precipitation slightly above normal. This could add slightly to the snowpack already on the ground.
The most important factor influencing flooding is rainfall, but even a normal snowpack adds risk. When water in the snowpack is released suddenly, by rainfall accompanied by warm temperatures, runoff amounts are increased dramatically. The best case scenario is for days above freezing and cooler nights, to melt snow gradually.
Snowpack water content ranged from 2 to 5 inches in southern and coastal sections to 7 to 9 inches in northern and western Maine, though some areas in the western mountains have 9-12 inches of water in the snow. Currently, the snowpack can absorb some amount of rainfall. These levels put water content in the middle range compared to historical averages across most of the state. Snow survey maps are available at the Commission's web site.
River ice is below normal in most areas of the State. The US Coast Guard and the USGS measured ice in the lower Kennebec River this week and found ice to be thin or nonexistent in many areas. As a result, the Coast Guard does not plan to break ice in the Kennebec this season.
Reservoir storages in the headwaters of Maine’s large rivers are being drawn down to prepare for spring rains runoff. River basin managers report that they are on track to achieve their drawdown targets.
McAleer said it is most important to check your flood insurance coverage if you live or have a business in a flood-prone area. “Most home and business owner’s policies do not cover flood damages. And there is 30-day waiting period before a new policy goes into effect,” he said. “The time to check your insurance is now.”
Commission members will stay in close communication throughout the spring season, and will meet again if conditions warrant. Snow surveys will be conducted each week from now until the snow cover is gone.
The River Flow Advisory Commission meets annually in late winter to share information, examine potential for spring flooding and to renew operational protocols. The Commission is composed of state, federal and industry representatives with an interest in hydrologic issues. The full report of the March 7 meeting will be available on the Commission's website by close of business on Friday.