White Bear Lake drying up: symptom of an emerging metro-area water problem

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White Bear Lake Restoration Association

What if White Bear Lake is only the beginning?

Here’s a scary thought: What if White Bear Lake is only the beginning?

The lake’s loss of a quarter of its volume over the past decade is a wake-up call for the Twin Cities, says Ali Elhassan, water supply planning manager for the Metropolitan Council.

“One of the biggest challenges for us is how we can switch from relying more on groundwater into other sources that are available here,” he says.

The status quo — 75 percent of the metro area depends on groundwater pumped from subterranean aquifers and just 25 percent uses surface water — just isn’t sustainable, Elhassan says.’

Municipal water use in seven-county Twin Cities Metro Area

Metropolitan Council

Currently, 75 percent of the metro area depends on groundwater pumped from subterranean aquifers and just 25 percent uses surface water.

Already, water levels in other lakes, including Turtle Lake in Shoreview, have diminished, he says, and in 2007 three of Chanhassen’s 11 municipal wells went dry.

“White Bear Lake is a symptom of the bigger problem,” Elhassan says.

Solving the problem is necessary both to ensure a stable supply of water and to guarantee that the area remains a desirable destination for economic development.

Changing Minnesota mindset

It will require big changes, starting with the tough task of shifting a classic Minnesota mindset.

“The challenge first of all is the perception of communities that we have an abundance of water,” Elhassan says.”We are the land of 10,000 lakes and planning for supply used to be built on water abundance.”

That doesn’t mean the region has a water shortage now or will soon have one, he says, but creating more balance in the water supply is essential to preclude that from ever happening.

The Minnesota Legislature authorized a $2 million study of water supply sustainability by the Metropolitan Council and $537,000 for the Council to hire the U.S. Geological Survey to study the changes that led to White Bear Lake’s problems.

Let’s pause here for some definitions:

• Groundwater: Water that lies beneath the earth’s surface. It comes from precipitation that infiltrates through the soil. Groundwater flows into many lakes and rivers and collects in aquifers.

• Aquifer: Underground storage reservoirs and pathways for water movement. They act like sponges. There are several aquifers beneath the metro area. Groundwater is pumped from wells, decreasing aquifer levels.

• Surface water: Water in rivers, lakes, streams and creeks. It is replenished mostly by precipitation but can include some groundwater flow.

Most communities prefer to extract groundwater from wells because it’s cheaper. “It’s more accessible, it’s cleaner,” Elhassan says. “You don’t have to treat it.”

Growth away from Mississippi

Water from the Mississippi River requires treatment before it can be used. Sixty years ago when most development was centered near the river, more than 80 percent of the water supply here came from surface water.

The shift of industrial, commercial and residential growth to areas far from the Mississippi prompted the reversal of that number.

That growth — and the accompanying spread of concrete, asphalt and other impervious surfaces — means less precipitation seeps through the soil to replenish, or recharge, water in aquifers.

Today, that means a plentiful local water supply is largely untapped. Each year, 5 trillion gallons of water move through the Mississippi, Minnesota and St. Croix rivers, Elhassan says.

Metropolitan Council

Groundwater moves from high pressure areas, usually where the aquifer is at a higher elevation, to low pressure areas. The area where groundwater comes from is called a recharge area; discharge areas are where groundwater reaches the land surface. Discharge areas may be nearby or very far away.

“We’re using 1 percent of that,” he says. “On top of that, we are putting back in the [Mississippi] about 300 million gallons a day water as treated wastewater.”

The Metropolitan Council is holding workshops now with residents and businesses in the northeast portions of the area. Solutions for White Bear Lake, including using water from the Mississippi, and implications for neighboring communities that rely on groundwater are being discussed.

But long-term answers are needed, Elhassan says.

Expensive change

A transition from reliance on wells to broader use of surface water, with the use of groundwater as backup systems, would be complex, expensive and lengthy, but it’s “the idea we want the communities to start to think about,” he says.

Elhassan also is working with several communities in the south and southeast metro areas who are concerned about water availability as they expand.

“By 2030 some of those communities will have different groundwater levels from now and they’re expecting growth,” he says. Their attitude, he says, stems partly from White Bear Lake’s woes: “We are worried about the future and we want to be proactive.”

Metropolitan Council

The aquifers of the Twin Cities Metropolitan Area consist of unconsolidated glacial deposits and underlying bedrock layers. They form a bowl shape called the Twin Cities Basin when viewed in cross section from west to east.

The Metropolitan Council is trying to identify locations where pressure on aquifers can be relieved, where new water treatment plants could be built, potential for stormwater reuse and other options.

“The first step,” Elhassan says, “is awareness.”

That means explaining to political leaders and residents the impact on aquifers if five or six communities are drilling new wells at the same time and the importance of water conservation.

Not everyone is convinced, Elhassan says. “In many places, to tell you the truth, there is denial.”

The challenge is enormous and so are the stakes.

It would take a big financial investment to funnel surface water to communities far from the rivers. Asking if it’s worth spending millions requires considering another question, he says: “How much will it cost to deal with a water shortage?”

“The cost of building this infrastructure right now is going to be cheaper,” he says, “than the cost of dealing with this crisis when it happens. Planning is our only tool to try to avoid such crisis situations.”