Bucknell University Professor Richard Crago, civil & environmental engineering, teaches his students to design solutions that protect and improve the natural environment around them. But he also wants them to remember that people live in that environment too — and that sometimes the best engineering solution is one those people will actually be willing to implement.
"They need to understand what the community wants, who the stakeholders are," he explained. "I'm working hard to help the students to understand why a Mennonite farmer might not want Bucknell students to tell him how to farm."
With both of those goals in mind, Crago partnered with a local watershed alliance, the Chesapeake Conservancy and Bucknell GIS specialist Janine Glathar to devise watershed protection tactics on local farms in the Buffalo Creek watershed, with the ultimate aim of improving water quality in the Chesapeake Bay, some 100 miles to the south. That meant hours carefully poring over GIS maps to identify areas that have the greatest impact on the environment around them and devising engineering solutions for those areas — a process the conservancy calls precision conservation. But it also meant getting out of the classroom one damp autumn morning to see the land they hope to improve, and meet the farmers who own it.
"We want to come up with a real-life engineering solution, like we'll be doing once we graduate," said Rahul Dhakal '16, a civil engineering major in Crago's class. "To make it as realistic as possible, we need to hear suggestions from the farmer, and get a sense of whether our plan is actually viable."
Students worked with GIS software to analyze land-cover classification and elevation data and calculate stormwater flow paths. Then, spreading out among the fields they had studied in the lab, the students checked their predictions against what was actually happening on the ground. Back in the lab, they used that data to find areas where water-protection projects would have the most impact, then devised solutions, including retention ponds, engineered swales (shallow, vegetated ditches) and vegetated streambank buffers.
"Chesapeake Conservancy taught us how to use aerial imagery and elevation data to create extremely high-resolution land-cover classification data," Glathar said. "With one-meter land-cover classification data instead of the typical 30-meter resolution, you can pinpoint much more precisely what is happening in a given area and make better, more effective decisions."
They also questioned farmers about their farming practices and efforts they've made to protect the land.
"We're here get a feel for what they're actually doing out here, and we've been able to talk to the farmers and hear what their thoughts are on best practices for managing runoff," said Max Wilder '16, a civil engineering major.
While the projects the students came up with are modest, collectively such small-scale projects can have a big impact. The Susquehanna River, into which the Buffalo Creek watershed drains, is the leading contributor of pollution to the Chesapeake Bay. Much of that pollution, primarily sediment and nutrients from fertilizers, originates on farms. Glathar and Crago are quick to point out that most of the pollution doesn't result from the farmers doing anything wrong; rather "it's about that land-cover conspiring with the elevation," Crago said.
"The Chesapeake Conservancy knows people think, 'I live 100 miles away from the bay — why should I care?' " Crago said. "They want you to understand that, actually, when you put fertilizer on your lawn it might end up in the bay eventually. One of the reasons the conservancy likes this precision conservation idea is that it lets you see at a highly detailed scale where pollutants are coming from."
Once in the bay, those pollutants create a variety of problems, filling in nooks and crannies on the bay floor, where many organisms live, as well as feeding algae whose eventual death and decay depletes dissolved oxygen, making it harder for animals to breathe. The problem is so severe the federal government has stepped in to help.
Ultimately, Crago and his collaborators hope farmers will adopt some of the solutions his students have proposed, and in some small way contribute to improving water quality in the bay.
"It should be easier to convince the farmers to do this in a few key spots than to do the whole stream," said Allan Grundstrom, an original board member and past president of the Buffalo Creek Watershed Alliance. "That's why this study is really a big deal for us. It's going to help us enormously."
"We can all learn from it," added Brock Saylor, one of the farmers whose land the students surveyed. "If they have ideas, I'm certainly willing to listen." Crago and Glathar also hope their project will be mirrored elsewhere, as the Chesapeake Conservancy, with help from a federal grant, is developing high-resolution land-cover data for the bay's entire watershed.
"By next summer, Chesapeake Conservancy will be providing land-cover classification data to anyone who wants to use it," Glathar said. "The students who worked with us on the research project in summer 2015 and in the hydrology class got to be on the cutting edge of a very exciting new approach to conservation and land management."