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

Navigation

MN 100: ContainerTug B.V.

The Company: ContainerTug B.V. is a specialized Dutch naval design engineering and construction company with a strong focus on developing workboats and the evaluation

Sunken Towboat Lifted from Neches River

A towboat that sank in Texas' Neches River August 21, and caused a temporary closure of the waterway, was lifted out of the water Wednesday Evening. T&T Marine,

Sailboat Catches Fire off Honolulu

A sailboat with five people aboard caught fire off Honolulu, Thursday, promting responsefrom the U.S. Coast Guard who sent a 45-foot Response Boat-Medium crew from

Environmental

China Passes New Pollution Law, Will Cap Coal Consumption

Legislators have approved amendments to China's 15-year-old air pollution law that grant the state new powers to punish offenders and create a legal framework to cap coal consumption,

Marad Celebrates Deployment of Maritime Fuel Cell Project

The U.S. Department of Transportation’s Maritime Administration (MARAD) today celebrated the launch of field trials for the first prototype hydrogen fuel cell

Panama Canal Suspends Draft Restriction

The Panama Canal Authority (ACP) has lifted scheduled vessel draft restrictions brought on by lingering draught conditions in the region.   The ACP had previously set restrictions of 11.

Coast Guard

Man Earns Jail Time for Hoax Coast Guard Calls

A man found guilty of making numerous hoax calls to the U.K. Coastguard has been jailed for four months, the U.K. Maritime and Coastguard Agency (MCA) reported.

Sunken Towboat Lifted from Neches River

A towboat that sank in Texas' Neches River August 21, and caused a temporary closure of the waterway, was lifted out of the water Wednesday Evening. T&T Marine,

Iranian Ship, Crew Escape Captivity off Somali Coast

An Iranian fishing vessel and its crew have escaped after being held captive for five months by Somali fishermen, maritime piracy experts said on Friday, but it

Maritime Safety

Man Earns Jail Time for Hoax Coast Guard Calls

A man found guilty of making numerous hoax calls to the U.K. Coastguard has been jailed for four months, the U.K. Maritime and Coastguard Agency (MCA) reported.

Tropical Storm Erika Heads for Florida

Tropical Storm Erika lashed Puerto Rico and the Virgin Islands with heavy rain and fierce winds on Friday, moving across the Caribbean and apparently heading for the Dominican Republic,

ClassNK to Issue Guidance on Composite Propellers

Classification society ClassNK announced it will release the world’s first Guidelines on Composite Propellers (Part on Manufacturing/Product Inspection) on August 31.

Government Update

Iranian Ship, Crew Escape Captivity off Somali Coast

An Iranian fishing vessel and its crew have escaped after being held captive for five months by Somali fishermen, maritime piracy experts said on Friday, but it

Migrant Boat Sinks off Libya; 200 Feared Dead

A boat packed with mainly African migrants bound for Italy sank off the Libyan coast on Thursday and officials said up to 200 might have died. A security official in the western town of Zuwara,

Oil Steadies as Equities Rally

Recovering stock markets boost oil prices; U.S. crude on track for first weekly gain in nine weeks. Oil prices steadied on Friday after bouncing back from six-and-a-half-year

 
 
Maritime Careers / Shipboard Positions Maritime Contracts Maritime Security Maritime Standards Navigation Pod Propulsion Salvage Ship Electronics Ship Repair Sonar
rss | archive | history | articles | privacy | 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: 0.3745 sec (3 req/sec)