Meet a Forest Hydrologist

By Robert Godfrey

Forest lands provide a clean and dependable supply of water and a handful of professionals – known as forest hydrologists – monitor our state’s water quality before, during and after forests are harvested. One is Nolan Kriegel. Through his work in safeguarding one of our major sources of clean water, he serves us all in this important job.

He has three major responsibilities. One of the most critical ones is monitoring what is known as Wisconsin’s Forestry Best Management Practices (BMPs) for Water Quality where his focus is on timber harvesting and its effects on water quality.

A forest hydrologist’s work life is largely dictated by the seasons. “I have different sorts of responsibilities depending on the time of the year,” said Nolan. “In the winter I am starting to collect data for the BMP monitoring visits that occur during the following fall season.”

He has five different types of landowner groups that he monitors: federal, state, county, large private landowners (owning over 1,000 acres) and small private landowner. Usually one or two landowner groups are monitored per year.  This year he will be focusing on small private landowners, also known as non-industrial private forests. Whatever the group he is monitoring, one of his responsibilities is to compile a complete list of harvests that were completed in the state for the past year.

But it is not always a simple process to get that information, especially for timber harvests by private landowners. there is no central database of timber harvests that occur on private lands in the state of Wisconsin.  Nolan has to collect the information from various sources and the data comes to him in different forms, with duplicates that need to be removed.

“Once I get all the data, I have to streamline it into a usable fashion,” Nolan said. After that is completed, the next step is to narrow down the list of suitable timber harvests. He must figure out which harvests have water resources close by. He does this using computer satellite reconnaissance data. Using this pre-screening process, he determines which harvests are close to lakes or streams. “If they look like they have crossed wetlands or waterways, those are the best, followed by those with water features around the border of the harvest; we will keep those. And that usually eliminates about half to almost two-thirds [of the harvests] right off the top.”

They try to do a good job during this screening process, but they don’t have the exact sale boundaries for private forests. It may be that the harvest took place nowhere near a water source. That happens about 10% of the time. This process is a lot easier for harvest sales that take place at the county, state and federal level because he gets their sale maps.

Based off the number of sales from the previous round of monitoring, the minimum sample size is determined. This is done to ensure statistically-valid results. Anywhere from 30 to 50 different property visits will then be made by Nolan Kriegel’s group in the spring time. These visits are done to make sure the site has water present where they harvested. If that proves to be the case, the site is selected for BMP monitoring in the fall.

But before they can make those visits, they must contact the private landowner to seek permission to go on their land. “Often we do not have a phone number or email. So, we have to do a bit of sleuthing for that information to find and contact them.”

These private forests can be very spread out across the state. “So, we try to meet with multiple land owners, even if they are a few hours away. It’s realistic to meet with three or four land owners per day depending on how close they are together. Then we walk through the harvests to make sure that it meets the criteria that we thought we would see, based on satellite imagery.”

What does a hydrologist look for when they come on to a piece of land? “I always walk to the water,” Nolan added, “whether it is a stream or wetland, especially if it is dividing the harvest. Then I look for crossings of water features or how close did that harvesting come to the edge of it.”

“The slopes are another thing I look at when I’m there.” They can cause many problems. If any mistakes happen, they are not forgiving. Bare soil after a timber harvest can lead to erosion. Slopes can make erosion even more likely. “It’s interesting to see how loggers and foresters can navigate around steep slopes while preserving water quality. Did they go up and down vertically along it, did they miss it all together, did they avoid mechanized logging but still hand-cut trees with a chain saw?”

In the fall, when the leaves are off the trees, a group of resource professionals goes out to each of the properties that were selected in the spring. They go through a 119-item BMP checklist. “It is a lot easier to walk around the landscape and see skids trails when all the leaves are down,” said Nolan. And they must complete their work before the snow falls. Essentially, they try to get all their monitoring done from mid-September to November.

In 2019, they evaluated 35 federal and 19 industrial sales and between the screening visit in the spring and the fall visit for monitoring, Nolan made it to almost all of them.

Winter is spent writing reports on the sites visited in the fall by the BMP monitoring teams and then preparing for reconnaissance visits again in the spring.

In addition, Nolan’s second responsibility is to provide trainings for landowners, loggers, foresters and other natural resources professionals. Nolan is also available for questions and site visits when asked by landowners, loggers, and foresters to help evaluate BMP options for forest management. These questions may be about how to best cross a stream or wetland or how to best build a road up a steep slope.

And lastly, Nolan is available any time a forester with public or private lands needs assistance with the permitting process for timber harvests involving wetlands or waterways. He is the person you can turn to when you have questions about the best way to cross streams for timber harvesting and how you can go about getting a DNR permit. “We can educate foresters and help them apply for the permit they will need to do a timber harvest. Whether it’s a wetland or stream crossing, we can help.”

The timelines for the permitting process for stream crossings or wetlands can vary considerably depending on the site. No matter what needs to get done, Nolan Kriegel is always there to help. Surely, he is a man for all seasons.

You can read some past monitoring reports and other BMP-related publications from Wisconsin DNR here. (We advise using the Chrome browser to open this link.)


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