Feature Article: Baseline Data, an Important Part of Adaptive Management at Pheasant Branch

By Garrett Hopkins, Rock River Coalition

Pheasant Branch Conservancy is superb sampling of Wisconsin’s natural eclecticism. Located in Middleton, the 549-acre ecological safe haven contains forested hills, freshwater streams, oak savannah, native prairie and a spring-fed, open-water marsh. And while the sprawling conservancy is an invaluable source of human-to-nature connectedness, it’s also a particularly consequential component of Dane County’s freshwater resources. Every day, more than 2.5 million gallons of freshwater flows from the springs of Pheasant Branch into Lake Mendota. For this reason, the conservancy has been a focal point of environmental restoration efforts for nearly three decades.

Through the years, countless conservation professionals have applied their expertise to the betterment of Pheasant Branch. One of these individuals, Herb Garn, has been doing so from the very beginning of the conservancy’s existence, through an organization called The Friends of Pheasant Branch Conservancy (FOPB). “I’ve been on the Board and have been a member since 1996,” he says. Garn, now retired, spent most of his career as a hydrologist and supervisor for the U.S. Geological Survey (USGS). “I had been doing a lot of research for the watershed through the USGS. That’s how I got involved in Pheasant Branch, and I’ve been volunteering there ever since.”

The 3,452-acre Pheasant Branch Watershed includes the North Fork in an agricultural region of Middleton and the South Fork near urban Madison. FOPB’s conservation work has centered on monitoring the pollutant loads (primarily phosphorus) that are carried into the conservancy through stormwater and agricultural runoff. “The conservancy is at the bottom end of the watershed’s drainage way,” explains Garn, “so sediment, nutrients and other stuff like seeds from invasive species come from the upper parts of the watershed, get deposited into the conservancy, then go into Lake Mendota.”

FOPB’s conservation efforts are in step with the Yahara Watershed Improvement Network (Yahara WINS), an unprecedented initiative intended to reduce phosphorus in the 170,000-acre watershed. Yahara WINS, launched by the Madison Metropolitan Sewerage District in 2012, uses a conservation approach called watershed adaptive management, which allows decision-makers to tailor a management plan to a specific region and issue, and adjust strategies as data fluctuates.

For Yahara WINS, adaptive management is a strategy in which all sources of phosphorus work together to reduce phosphorus. Pheasant Branch Creek, partially located in the Pheasant Branch Conservancy, is one of eight paths in which phosphorus travels into the Yahara Watershed and is therefore a critical piece to the success of Yahara WINS’ adaptive management approach.

One measurable objective of Yahara WINS – reducing phosphorus loading into Lake Mendota to 50% – requires an extraordinary amount of time and coordination and is reliant on large amounts of data gained through stream monitoring. Stream monitoring provides critical baseline and ongoing data, and for this reason, is the crux of FOPB’s phosphorus reduction work in the conservancy.

“We collect data on critters and basic water quality information like water temperature, clarity, dissolved oxygen and nutrient content,” says Garn. FOPB assists others in monitoring five sites on Pheasant Branch Creek, two that are within the conservancy and three that are upstream on the North Fork.

But perhaps most importantly, in the year 2003 FOPB began monitoring a 159-acre dairy farm that was adjacent the conservancy. “I started monitoring flows coming from the farm that flowed into the conservancy,” says Garn. “We learned the farm was not using any conservation practices to speak of, so Dane County constructed two sediment ponds within the conservancy to try to trap some of the water from the farm before it flowed into the marsh.”

Garn conducted a three-year study (2003-06) that proved the ponds were not making enough of an impact. In 2009, FOBP worked with the landowners, the DNR and Dane County Land & Water Resources Department to install a broad range of conservation practices on the farm. Garn then conducted a second three-year study (2010-12), which showed improvements but ultimately ascertained the need for a more drastic management approach. His data was presented to the County and, in 2019, Dane County decided to purchase the land, remove the farmstead and restore all 159 acres to prairie.

“Since 2019,” says Garn, “Friends of Pheasant Branch and the County have been planting portions of the farm. As of this past spring, the entire farm has been seeded to prairie plants.”
The results are already astonishing. “Since 2003, we’ve had a greater than 90% reduction in total solids and 75% reduction in phosphorus concentrations, and the prairie isn’t even fully grown up yet. And most importantly, there’s a tenfold reduction of runoff from the farm.”

In addition to their robust stream monitoring regiment, FOBP’s work with the dairy farm is among Rock River Basin’s most impactful conservation projects in recent history. Garn was happy to discuss this monumental achievement but – as most lifelong conservationists usually are – seemed more interested in looking toward the future. “The key now is how we use this data. We have 20 years’ worth of quantitative data to show people that restoration works, that it’s possible to reduce runoff and phosphorus by conserving wetlands and prairie.”

The success story of Dane County’s new 159-acre prairie – all of which is now part of Pheasant Branch Conservancy – is proof of concept for adaptive management. The team remained persistent and flexible, and relied on data to find the most effective solution. The prairie is also a source of inspiration for all who hope to see a cleaner, healthier and (even) more beautiful Rock River Basin. If you are looking for a special place to spend a warm summer day, consider visiting the Pheasant Branch Conservancy! 

Learn more about the Pheasant Branch Conservancy here: visitmiddleton.com/recreation/pheasant-branch-conservancy.

Learn more about The Friends of Pheasant Branch Conservancy here: pheasantbranch.org.