Thoughts From Engineers: Stepping Up Source-Water Protection
If a watershed was the subject of a play, this one could fill the house. Set in southwestern Wisconsin in a watershed known as Black Earth Creek, the plot has some interesting elements: a failing landfill; a Class 1 trout stream; development pressure from a bustling urban area nearby; and a cast of supporting characters that includes farmers, a few quirky residents, developers, local officials and more. But if you thought this play would be all downhill from here (no pun intended), you would be wrong. Aside from the 1980s incident involving the leaky landfill, which was capably dealt with, all other parameters indicate that Black Earth Creek—a primary source of the region’s drinking water, among other uses—is on an upward trajectory in terms of the quality of its management.
The case offers some important lessons relating to source-water protection, an all-too-important topic as more communities across the United States grapple with contaminated drinking-water supplies. A recent investigation by Consumer Reports and The Guardian showed that roughly 35 percent of tap-water samples collected at random throughout the United States were found to be contaminated by PFAS, an infamous “forever chemical,” and 8 percent had high levels of arsenic. Nitrate contamination is increasingly common in wells throughout Wisconsin, as is contamination by atrazine, an herbicide associated with agricultural activities. The list of similarly affected communities across the United States goes on.
As experts have lately pointed out, drinking water is a uniquely challenging resource to manage. We’ve created agencies and regulatory systems, and built the necessary infrastructure to protect, manage and distribute our water resources. These take the form of point-source permits for specific discharges, stormwater ordinances for polluted runoff, and infrastructure that collects and treats our waste. These systems work well—to a degree. But in most cases, these agencies and systems work independently of one another and independently of something far more basic: the raw hydrologic processes that underlie the interconnections and flow of water.
The Main Disconnect: Hydrology Does Not Follow Political Boundaries
The Black Earth Creek Watershed is a relatively small watershed that drains approximately 45 square miles of terrain consisting of steep woodland areas, agricultural lands and, increasingly, developing urban areas. The watershed is a short drive from where I live in Madison, Wis., a fast-growing metropolitan area of roughly 270,000 people. Development pressure has increased significantly in the idyllic rural communities of southwestern Wisconsin, mirroring trends apparent throughout the United States.
Black Earth Creek has been classified as an “Outstanding and Exceptional Resource Water” by the Wisconsin Department of Natural Resources and supports a self-sustaining population of roughly 1,600 wild trout per square mile. It’s estimated that nearly 80 percent of the Creek’s streamflow is groundwater discharge. The multiple springs in the Black Earth Creek valley are principal indicators of the strong hydrologic connections between the region’s Cambrian-era aquifer and the area’s lakes and rivers. The groundwater that supplies drinking water to the cities and villages in the watershed as well as the trout stream and its tributaries is one hydrologic system—plain and simple. Land-use activities that affect one element of the system will invariably affect the rest, and vice versa.
By virtue of the watershed’s proximity to the University of Wisconsin-Madison as well as the state capital, and due to its status as an outstanding resource water, the watershed and its associated geophysical and biological features have been extensively studied, inventoried and mapped. These studies and the data collected guide many planning decisions in the Black Earth Creek Watershed.
Partnerships at Work
The Black Earth Creek Watershed is made up of several units of government, but one influential actor behind the management of the watershed is an entity made up of citizen-residents: the BECWA. This organization educates; facilitates communication among landowners, interest groups and municipalities; and solidifies the partnerships and trust that help the watershed work toward common goals. The BECWA was organized on the principal that management along political boundaries was inadequate to deal with a resource that moved independent of political boundaries.
The organization’s positions have been controversial at times, but the group has found common ground with most interest groups, using surveys and other tools to identify overarching goals. The BECWA’s mission to protect the region’s water resources informs municipal land-use plans, zoning and the siting of industrial operations, including conditions placed on residential and commercial development. Some measures include deed-mandated rain gardens for residential lots, widespread stormwater infiltration standards, and restored stream corridors fortified with vegetated swales and other green infrastructure, to name just a few. Funding on the order of $2 million also helped the sizable farming community implement measures designed to minimize risk of contamination from agricultural operations.
Land surrounding sensitive groundwater recharge areas and headwaters as well as large swathes of shoreline and wetland have been purchased outright or protected through conservation easements. A premium is placed on scientific analysis via data collection and frequent technical input from the U.S. Geological Survey, the University of Wisconsin and other consultants. Stream gages and other IoT-enabled devices gather data along the stream channel and at multiple points within the watershed; monitoring equipment is purchased on an annual basis.
Minding the Watershed
It’s anyone’s guess as to how the watershed will develop in the next 50 years and what—if any—will be the associated effects on the watershed’s resources. It’s entirely possible that in spite of the proactive approach of the watershed’s municipalities, BECWA and others involved, widespread drinking-water contamination will still occur. As long as industrial, agricultural and other contaminants remain in circulation, the risk is real and ongoing.
I suspect, however, that Black Earth Creek would be in significantly worse shape if the practices reminiscent of a “business as usual” approach had dominated. After all, measures to protect source water are not a federal mandate, only a recommendation. In the end, this case demonstrates that more than a set of agencies, government units and regulatory systems is needed to protect drinking-water resources now and into the future. Strong local partnerships are needed as well as a level of oversight beyond what the status quo offers. In addition to the technical knowledge of engineers, modelers and regulators, we need the “buy-in” and partnership of citizen interests with a stake in the quality of our water resources.
About Chris Maeder
Chris Maeder, P.E., M.S., CFM, is engineering director at CivilGEO Inc.; email: [email protected].
