Up to 375 flood gauges to turn off because of fund cuts Detroit Free Press (4/26) Just in time for the spring flood season, the federal sequester is threatening to shut off funding for hundreds of stream gauges used by the U.S. Geological Survey to predict and monitor flood levels across the country.
Water supply down, Lake Superior drops Duluth News Tribune (4/3) Lake Superior dropped two inches in March, a month it usually drops only a half-inch, the International Lake Superior Board of Control announced Tuesday.
Boaters lament low lake levels The Windsor Star (3/12) Recreational boaters are concerned given that lakes Huron and Michigan had record lows in January and lakes St. Clair and Erie are expected to see only modest rises over the next month.
Weather conditions:
Wet conditions continued across the Great Lakes basin this week due to heavy rain, wet soil conditions, and continued snow melting in the northern areas. Overall, the basin has received 180% of average precipitation for the month of April, with the Michigan-Huron basin receiving over 200% of average. Temperatures dropped below average on Wednesday and Thursday but are expected to warm up over the weekend. Expect low chances of precipitation over the weekend with above average temperatures heading into next week.
Water Level Conditions:
The water levels of the Great Lakes have risen significantly over the past month. Lakes Superior and Michigan-Huron are 2 and 7 inches, respectively, lower than their levels of a year ago. Lakes St. Clair, Erie, and Ontario are 6, 8, and 3 inches, respectively, lower than at this time last year. Over the next month, Lakes Superior and Michigan-Huron are both forecasted to rise 3 inches. The water levels of lakes St. Clair, Erie, and Ontario are expected to rise 1, 2, and 3 inches, respectively, over the next thirty days.
See the Great Lakes Water Levels web page for more water level information.
Forecasted outflows / channel conditions:
Lake Superior’s outflow through the St. Marys River is projected to be below average for the month of April. Lake Huron’s outflow into the St. Clair River and the outflow from Lake St. Clair into the Detroit River are also expected to be below average throughout the month of April. Lake Erie’s outflow through the Niagara River is predicted to be below average and the outflow of Lake Ontario into the St. Lawrence River is expected to be below average in April.
Alerts:
Official records are based on monthly average water levels and not daily water levels. Lake Superior and Lake Michigan-Huron are below chart datum. Users of the Great Lakes, connecting channels and St. Lawrence River should keep informed of current conditions before undertaking any activities that could be affected by changing water levels. Mariners should utilize navigation charts and refer to current water level readings.
Overview
Carved by glaciers, the Great Lakes-St. Lawrence River system is a series of steps that drains from Lake Superior in the west to the Atlantic Ocean in the east. Covering more than 94,000 square miles, the Great Lakes and their connecting channels form the largest fresh, surface water system on earth, holding about 18 percent of the world's supply.
Ever since the last glaciers retreated about 10,000 years ago, the system's water levels and outflows have been fluctuating, affecting the lakeshore environment and human activities. Unlike oceans, where ebbs and tides are constant and predictable, Great Lakes water level fluctuations are almost never regular, nor can their levels be predicted accurately in the long term. This is because the many factors affecting Great Lakes water levels and flows are never constant and likely can not be predicted accurately in the long term.
The major influences on Great Lakes hydrology are weather and climate, which affect the balance of water in the Great Lakes and their connecting channels. Water enters the system as precipitation, runoff (including snowmelt) from the surrounding land, and groundwater inflow. Water leaving the system consists of evaporation from the water's surface, groundwater outflow, consumptive uses and diversions.
The GLIN hydrology section discusses these factors and links to resources from many relevant agencies. We hope that an understanding of the Great Lakes system's dynamics will promote living in harmony with one of the most precious natural resources of this planet.
Coordinating Committee Co-chairs:
John Kangas
U.S. Army Corps of Engineers, Great Lakes and Ohio River Division john.w.kangas@usace.army.mil
Peter Yee
Environment Canada, Great Lakes-St. Lawrence Regulation Office peter_yee@pch.gc.ca
Education TEACH Great Lakes: Water Levels Water levels are part of the ebb and flow of nature. Learn about the three types of water level fluctuations, how levels are measured on the Great Lakes, and what's causing the recent drop.
References Great Lakes Water Levels Home Page U.S. Army Corps of Engineers (USACE), Detroit District A regularly updated page of links to information on Great Lakes hydrology. Includes current conditions, recent water levels, forecasted levels, general news and information, multimedia, reference materials, and more!
Great Lakes Atlas U.S. Environmental Protection Agency (EPA) This Environmental Atlas and Resource Book is an excellent resource on the Great Lakes, including physical characteristics, natural processes, people, concerns, joint management and new directions (mirrored on Environment Canada's site).