How Do You Know If A Stream Is Healthy?

One day last summer, I took the road WAY less traveled. It was a blistering hot day and I was on an odyssey with the kid and dog, trying to find a fabled route to the St. Croix River from a secret location in western Wisconsin. In short, it was the kind of adventure that a normal person would never embark upon.  Our first false start led us deep into the woods down an overgrown trail where raspberry vines clawed at my legs. From atop my shoulders, my son slowly slurped away at the water in my Camelback until not a drop was left for me or the dog. After a slow and sweaty hike back to the car, we gathered more food and water and headed down the road to try another trail. There, we discovered a treasure in the woods – a spring-fed stream with water so cold it made my feet ache, a plunging waterfall, and a mossy fairy wonderland with a prince turned into a frog. We stayed and played for hours, deciding the river could wait for another day.

This way to the road less traveled.

Dozens of streams crisscross Washington County. There are cold, groundwater-fed trout streams like Brown’s Creek, Arcola Creek and Valley Creek that wind through wooded valleys to the St. Croix River. There are warm-water streams like Hardwood Creek and Clearwater Creek that connect lakes and wetlands in the upper reaches of the Rice Creek Watershed. There are also intermittent streams that flow only occasionally, when the snow melts or lake water levels get too high. In total, the Washington Conservation District monitors 44 stream locations in the county, including a handful of stormwater pipes that transport water underground through now-developed landscapes.

Collecting water quality data from streams is not nearly as easy as collecting data from lakes and rivers. Not only are streams difficult to access, but they also transform continually throughout the year, and even from day to day, as they swell with rain and then disappear in the summer heat. For this reason, the Conservation District installs automated sampling equipment to collect water samples during storm events. The samplers activate when water levels reach a certain depth and then collect samples once every 15-min. or once every 30-min. until the rain is over. Monitoring staff also collect water samples by hand once a month between April and November, as well as during the spring snowmelt. In addition to recording water levels, flow rate, temperature and dissolved oxygen, staff also send water samples to a laboratory to measure phosphorus, total suspended solids (TSS), chlorides (salt), nitrates, heavy metals, and E. coli (bacteria).

Automated samplers allow the Conservation District to collect stream water samples throughout storm events.

Water quality monitoring provides the Conservation District and local watershed districts with consistent data that can be used to evaluate long-term trends (ie. Is a stream getting better or worse?) and also enables them to detect invisible pollutants like E. coli that can make people sick. In addition, fish surveys and macroinvertebrate sampling are conducted periodically to create a more comprehensive assessment of stream health. Students at Stillwater Area High School participate in the state’s Volunteer Stream Monitoring Program by conducting macroinvertebrate sampling on Brown’s Creek and Valley Creek twice a year. Biology teachers Andy Weaver and Ben Straka use the streams as an outdoor classroom where the students learn how to collect insects and other critters from the streams and practice sorting and identifying the tiny animals they find using taxonomic keys. Based on the number and diversity of species they find, they then calculate an “index of biotic integrity.” Results are presented to the Brown’s Creek and Valley Creek Watershed District boards each year.

Students from Stillwater Area High School assess aquatic invertebrates in Brown’s Creek and Valley Creek each year.

When water quality monitoring identifies a problem, watershed districts will typically follow-up with more in-depth analysis. For example, after monitoring staff determined that E. coli was a problem in Kelles Creek in Afton, the Valley Creek Watershed District conducted additional research and determined that the bacteria is coming from failing septic systems that are leaching wastewater into the shallow groundwater aquifer that feeds the stream. In contrast, the Brown’s Creek Watershed District determined that E. coli contamination in the upper portion of Brown’s Creek is coming from animals, not humans. More research will be conducted this year to determine whether wildlife or farm animals are the culprits.

Though stream monitoring can be complicated, the goals of local watershed programs are easy to understand. Resource managers envision a future in which every stream hidden in the woods is clean enough to play in and able to support fish, wildlife, and fairy wonderlands.

Our goal is to have streams clean enough for any kid to play in.