Rocks are weeping along the St. Croix River. If you hike along the river’s edge, you can see clear, cold water trickling down the sides of their walls and burbling to the surface year-round. In seepage swamps, found low at the bases of cliffs, skunk cabbage blooms in late winter, while in the spring, rare and tiny flowers called false mermaid bloom quickly and then disappear. Aquifers feed this mystical space where land meets water.
So too, aquifers supply the clear cool water that feeds Valley Creek in Afton and Square Lake, north of Stillwater. Like many lakes, streams and wetlands in the area, they are almost entirely fed by groundwater that seeps upward from underground. In other places, such as the flat, sandy outwash plains between Lake Elmo and Cottage Grove, rain and melting snow soak easily into the ground and percolate down to refill the aquifers.
The second week of March was National Groundwater Awareness Week. One hundred percent of the drinking water in Washington County, and for that matter most Minnesota communities outside of Minneapolis and St. Paul, is pumped directly from underground aquifers. Through a network of private, municipal and commercially owned wells, communities in the east metro tap into the unconsolidated Quaternary, Prairie Du Chien limestone and Jordan sandstone aquifers. We turn to the same reservoirs of water that seep from cliffs along the St. Croix and use them for drinking water, as well as to irrigate farm fields, water lawns, power factories and flush toilets.
Groundwater literally makes our lives possible. Yet, like the Giving Tree in Shel Silverstein’s storybook, we tend to take it for granted. If aquifers were more like lakes, maybe then we would love them. A lake can be swam in, fished from, or ice skated upon. You can sit in a lawn chair and gaze out dreamily across a lake, dip your toes in the water and then skip a rock across its surface. An aquifer gives us few such visceral pleasures. Groundwater is essential, practical, and yet so terribly uncharismatic. An aquifer is a wet rock, an area where water fills the pore spaces in limestone and sandstone, not even an underground pool or a labyrinth of watery passages.
If we learn to recognize groundwater in the unique places it springs to the surface, though, we might begin to appreciate it for more than just utilitarian purposes. Nearly a dozen designated trout streams flow into the St. Croix River in Washington County. Only southeastern Minnesota and the North Shore have as many trout streams, and the fish can only survive in these streams because of the cold, spring-fed water from underground. Three of the most rare plants in the Lower St. Croix River watershed – American water-pennywort, false mermaid and bog bluegrass – are found only in seepage swamps, where groundwater bubbles to the surface. During the winter, parts of groundwater fed lakes and wetlands remain open, giving many birds and animals a critical lifeline to survive during the hardest time of the year.
We have become so efficient at making use of our groundwater resources, that we often forget they are neither limitless nor invincible. Though it may appear that there is enough water for us to run the shower as long as we please, water the lawn everyday and ignore the leaking toilet, many communities are already feeling the pinch, especially during the summer. If we draw down our aquifers faster than they can be naturally replenished, we incur astronomical expenses to drill new, deeper, private and municipal wells and increase the risk of contaminating our remaining groundwater resources. When the aquifers get too low, some communities will have to draw drinking water from the Mississippi River. It’s hard to predict how the seepage swamps and trout streams will fare.
There are a few key things that you can do to protect our groundwater and aquifers. While you are still trapped inside this winter, take time to fix leaking toilets and sinks and choose low-water use fixtures if you are replacing old dishwashers, washing machines and water heaters. When the summer finally comes, use our groundwater resources sparingly for your lawn. Water your lawn, not the sidewalk, and follow your city’s watering restrictions. Finally, be cautious with fertilizers, pesticides and other household chemicals, as those can easily make their way into our groundwater drinking supplies. Take household hazardous waste like cleaners, paints and used engine oil to the Washington County Environmental Center at 4039 Cottage Grove Drive in Woodbury. The county also recommends that people with private wells test their water annually for total coliform bacteria and nitrates. Call 651-430-6655 to request a sample kitor visit the Public Health and Environment’s website to learn more.