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River Ice Network Mission Statement |
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An ice jam is an accumulation of ice in a channel that restricts the flow of water. This flow restriction can lead to rapid and substantial increases in stage upstream of the jam and equally substantial decreases in stage downstream. Ice jams can cause severe local flooding, and disrupt navigation, municipal water supplies and hydropower operations. When they break up and flow downstream they may erode river beds and banks, destroy wildlife habitat, and damage structures such as bridges and dams. Ice jams cause over $100 million in damages annually in the United States and can occur throughout the northern tier of states and even mountainous regions as far south as Arizona and New Mexico.
Efforts to mitigate the problems caused by ice jams are often hampered by a lack of data. When ice jam problems arise, there are typically little or no data describing the development or the current condition of an ice jam. There is also a lack of historic river ice data needed to develop predictive models for a particular site.
The North Central River Forecast Center (NCRFC) in cooperation with the U.S. Army Corps of Engineers (USACE) is conducting a cooperative river ice monitoring network for river basins in the North Central Region of the United States. The network provides weekly ice reports to support seasonal mitigation of problems caused by ice jams, and has begun to build a database which would aid in the development of river ice models.
The network is a cooperative effort between federal, state, and local agencies. The NCRFC uses its facilities to store and distribute the data and provide a means for observers to transmit data to the NCRFC database. Additional support is provided by interested federal, state, and local agencies to identify and select locations on rivers where ice jam flooding is a recurrent or serious problem. These interagency cooperators also help enlist or provide field observers.
The initial implementation of the network was held during the winter season of 1995-1996 and includes data collected by the USGS, USACE, the NCRFC. Initially, the network plans to become be established on a small scale, primarily in Minnesota, before attempts are made to extend it to other states in the North Central Region. Observers monitor some or all of the following variables on a weekly basis depending on their qualifications and the ice conditions. The USGS will be collecting data at each site two to four times a winter when they take flow measurements.
An observer handbook is planned to document standardize methods and procedures for taking ice measurements and characterizing river ice is being developed. The handbook would also outline safety guidelines for working on or near the ice and include an observation form and instructions on transmitting data to the NWS database.
With the help of other federal, state, and local agencies, a river ice monitoring network could become a reality in the North Central Region. It is hoped that such a network will help provide earlier and more accurate warnings of ice related flooding, supply other agencies with more centrally located information to effectively mitigate the effects of ice jams, and build a database for the development of predictive models.