Managing Ice Jams

MarineLink.com
Wednesday, April 09, 2014
Photo: Karen Watson, U.S. Geological Survey

April showers may bring May flowers, but spring can also bring ice jams to the thawing rivers and streams across the northern United States.

An ice jam or ice dam, is a buildup of broken ice in the river system. It can be a problem that causes the water to back up over the top of highway bridges, roads, or into cities. At times, they can cause flooding. Ice jams can be large–backing up water for miles, or small and only back up water in a small area locally.

An ice jam can damage bridges with the amount of water pushing on the jam from behind; it can force the ice to push the bridge – moving it slightly.

USGS monitors ice jams across the north using cameras as well as by collecting ice thickness information when technicians do regular streamgage work or when measuring discharge on the rivers in the spring.

For example, each year, the Maine Emergency Management Agency and U.S. Coast Guard asks the USGS to measure the ice thickness and provide an ice jam flood potential on the Kennebec River. The U.S. Coast Guard has used their ice breakers to clear the ice in the lower Kennebec River in years when the ice jam flood potential was high.

Greg Stewart, data section chief for the USGS New England Water Science Center, said its part of the agency’s job to monitor river flows throughout the state of Maine and to measure the stream flow underneath the ice.

USGS technicians take ice cores to measure ice thickness at various places on the rivers. In order to make an ice measurement, it’s necessary to drill between 25-30 holes in the ice. Then, thickness is recorded at just several of the holes to help document the measurement conditions.

That information allows the USGS to assess the risk of ice jams, flooding or other problems when the ice begins to melt, Stewart said. According to Stewart, when ice jam flooding starts to happen, there is very little time and very little warning.

Thickness of the ice and how fast a melt occurs affects the ice jam flooding potential. For example while the weather is cold, and the water is freezing you have ice accumulation. When the weather changes and it starts to warm the ice begins to melt and begins to break up. A quick warmup with the ice strong and still in place can cause significant ice jam flooding.

Another sign of spring is the melting snowpack, which is the result of accumulated layers of snow with generally more at high altitudes. Snowpacks feed rivers and streams providing an aquatic life habitat, hydro power, a possible source of drinking water, but they are also a potential flood hazard.

With a quick warm up of high temperatures over a short period of time, there is an increased likelihood of flooding from snowpack melt, but when you have a gradual increase in spring temperatures with moderate temperatures during the day and slightly below freezing at night the flooding potential is decreased slowly and safely.

According to Stewart, when the snowpack starts to melt historically March, that’s when snowmelt driven runoff begins, the USGS looks at the flooding potential.

usgs.gov
 

  • Photo: Iowa Water Science Center, U.S. Geological Survey

    Photo: Iowa Water Science Center, U.S. Geological Survey

Maritime Reporter March 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Navigation

Power Cut in Turkey Disrupts Port Operations

Port operations in Turkey are facing disruption as a result of a massive power cut that has hit dozens of provinces across the country today (Tuesday 31 March).

USCG Rescues 9 from Canadian Tall Ship

Coast Guard search and rescue crews from Station Gloucester, Air Station Cape Cod and the Coast Guard Cutter Ocracoke rescued nine crewmembers from the Canadian

Great Lakes Losing Ice

The Great Lakes Environmental Research Laboratory reports ice cover for all of the Great Lakes combined at around 52%, thanks to milder temperatures and gusty winds over the past several weeks.

Environmental

Holland America Line Wins Sparkie Award

At a March 5 reception at the Seattle Waterfront Marriott, Holland America Line was presented with a Sparkie Award by the United Way of King County, Washington.

Interior opens Alaskan waters to Shell

Today, the Department of the Interior issued a Record of Decision affirming Lease Sale 193 in the Chukchi Sea in Northwest Alaska. The federal government unlawfully

Focus on Environment at Suny Maritime College Anniversary

The State University of New York Maritime College’s 140th Anniversary Speaker Series presented a panel discussion on March 26 in the College’s Maritime Academic Center.

Coast Guard

Costa Concordia Used For Mafia Drug Smuggling

The doomed Costa Concordia was carrying a huge shipment of Mafia-owned cocaine when it set off on its final voyage, AP reports quoting investigators who have collected evidence.

WaPo: Two German CEOs Launching Own Mediterranean Rescue

The Washington Post has a story today about two German men who are launching their own rescue mission to save migrants crossing the Mediterranean.   Harald

All American Marine Delivers Ferry to Seattle

All American Marine, Inc. (AAM) today announced the delivery of a new passenger ferry that will serve the city of Seattle.    The vessel, MV Sally Fox, was dedicated

Maritime Safety

China's Artificial Islands in South China Sea Raises U.S. Concerns

China has been building artificial islands on reefs in the many disputed areas around the South China Sea. The unprecedented land reclamation currently being conducted

Going Nuclear in Indian Ocean

As India, Pakistan and perhaps China develop their naval nuclear forces, they will enter increasingly murky waters, says a report published in the National Interest.

Costa Concordia Used For Mafia Drug Smuggling

The doomed Costa Concordia was carrying a huge shipment of Mafia-owned cocaine when it set off on its final voyage, AP reports quoting investigators who have collected evidence.

Government Update

Largest Vessel to Call ICTSI, Rijeka

Adriatic Gate Container Terminal (AGCT), International Container Terminal Services, Inc.’s (ICTSI) container handling facility in the Port of Rijeka, Croatia,

EU Takes Tough Stance on Ship Scrapping in South Asia

The EU is set to ban owners from scrapping ships on South Asian beaches, according to news report in Reuters.   The new rules will require that EU-registered

U.S. DoI Upholds 2008 Shell Arctic Lease

The U.S. Interior Department on Tuesday upheld a 2008 lease sale in the Chukchi Sea off Alaska, moving Royal Dutch Shell a step closer to returning to oil and gas

 
 
Maritime Careers / Shipboard Positions Maritime Standards Naval Architecture Navigation Pipelines Salvage Ship Electronics Ship Repair Shipbuilding / Vessel Construction Sonar
rss | archive | history | articles | privacy | terms and conditions | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.1874 sec (5 req/sec)