Underwater vehicle to map out sources of groundwater in White Bear Lake

July 9, 2011 - via Pioneer Press

Scientists looking into the low water levels on White Bear Lake have called in a new weapon to help their research. The EcoMapper, a torpedo-shaped "autonomous underwater vehicle," according to its manufacturer, will cruise the depths of White Bear over the next week, collecting data on water temperature and quality.

The goal?
To create a map that shows where groundwater is flowing into the east metro's largest body of water. The $20,000 submersible project is an addition to the $200,000 U.S. Geological Survey project taking place in and around the lake, said Perry Jones, a Geological Survey hydrologist heading up the research.

The larger study, aimed at figuring out how surface and groundwater interactions affect the lake level, is being funded by the Geological Survey and a consortium of lake stakeholders including the Minnesota Pollution Control Agency; Ramsey County; and cities such as Birchwood, White Bear Lake and White Bear Township.

The cost of the EcoMapper - on loan from the U.S. Geological Survey in Indiana - is being split between the agency and the White Bear Lake Homeowners Association. The latter has also contributed to the main study.

The lake, which has risen 9 inches since January, is still about 4 feet below its normal levels, according to data from Ramsey County. Scientists with the Minnesota Department of Natural Resources have said the lake is low because of a micro-drought that is centered over the region and because it has a smaller-than-normal watershed.

Mark Sather, White Bear Lake's city manager, said residents are still looking for answers to the poor condition of their namesake lake. During a stop at an area business this past week, Sather said a resident approached and immediately started chatting about the lake. "Here, the hottest topic is still the lake level," Sather said.

Because the study won't provide solutions to the dropping level - but rather insights into areas to study further - Sather said the city's main role now is managing expectations. "It's not going to answer all of the questions," he said of the study. But it should get researchers closer, Jones said.

Before it heads out on its first mission, the EcoMapper will be on public display beginning at 8 a.m. Monday at the Ramsey County beach on White Bear Lake, Jones said.

The 5-foot-long, propeller-driven vehicle will have its route programmed into it before it is lowered into the lake from a boat. Once underwater, it will cruise at about two knots - or about 2-1/2 mph - as it collects information about water temperature, and its acidity and the amount of dissolved oxygen in the water, Jones said.

"We've talked to local divers and local residents and they've given us ideas where there might be springs coming in," he said. "We'll use this tool to kind of confirm it or not. We want to verify at this point in time what we see."

As part of the larger study, Jones said well-water-level readings taken in March and April will be compared to well readings to be taken in August to see if water usage causes the aquifer underlying the lake to rise or fall. "We want to do a comparison to see how much of an impact the people in the area have. How much are we stressing the aquifer systems?" Jones said.

A draft report is expected in February 2012, Jones said, with a final report expected in September 2012. "It won't address various issues with augmentation," Jones said. "It's really to get an idea of what are the controlling factors causing changes in lake levels."

External link: http://www.twincities.com/localnews/ci_18448166?nclick_check=1

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Author:John Brewer