UNIVERSITY PARK, Pa. — As Pennsylvania streams go, Conewago Creek in Dauphin, Lebanon and Lancaster counties is really nothing special.
But it could hold the key to cleaning up the Chesapeake Bay.
Draining a rural, agriculture-dominated watershed of about 53 square miles and providing a water supply for the Elizabethtown area, the Conewago empties into the Susquehanna River near Three Mile Island at Falmouth.
It’s a small stream in places, but much of it has been declared “impaired” by the state Department of Environmental Protection. It is too polluted to sustain fish and other aquatic life. Assessments have identified sediment and nutrients from runoff as the major cause.
Because of this, the stream is the perfect laboratory for an experiment to see if nonpoint source pollution can be controlled and largely eliminated.
Penn State’s College of Agricultural Sciences, collaborating with a local watershed group, county conservation districts, USDA’s Natural Resource Conservation Service, municipalities and landowners recently launched a demonstration project in the Conewago watershed.
“If what we are trying to do works here, we believe it can work in tributaries throughout the Chesapeake Bay watershed,” said Matt Royer, director of the Lower Susquehanna Initiative for Penn State’s Ag and Environment Center.
The Conewago, which marks the county line between Dauphin and Lancaster counties, is not victimized only by agricultural runoff. While there are about 270 farms in the watershed, the creek also receives storm water runoff from development.
Using grants from the state Department of Environmental Protection, the organization mobilized volunteers to plant trees along streams and to implement stream-bank-restoration projects.
The association even developed a watershed assessment and restoration plan, identifying 129 priority projects to improve the creek’s water quality.
“But we couldn’t do it all alone — we realized we needed help, we needed partners,” Royer said.
According to Royer, Penn State was looking to work with conservation districts and grassroots-based partners in an “ag-impaired” watershed in the excess-nutrient hot spot of south-central Pennsylvania. The fact that Royer’s group already had done an assessment and restoration plan made the Conewago all the more attractive.
To start, Penn State is increasing outreach and education in the watershed, trying to tell as many farmers and residents about why clean water is important — and trying to get them excited about improving water quality.
“We want them to make a fundamental shift to adopt the land management practices that improve water quality,” Royer said.
For farmers, this means ensuring every farm has up-to-date conservation plans and nutrient- or manure-management plans, required by state law.
Core best-management practices being promoted in the watershed include using conservation tillage, such as no-till, to eliminate soil loss; planting of cover crops in growers’ rotations to have plants in the soil all the time, even through winter, to reduce erosion; managing nutrients by using proper manure-application rates and reducing runoff from barnyards; erecting stream-bank fencing and riparian buffers to keep livestock out of streams.
Forested buffers outperform grass buffers, Royer pointed out. At the same time, Penn State researchers and extension educators are developing innovative practices that minimize nutrient loss while maximizing yields and bottom lines.
“Manure application is a challenge in a no-till scenario because the manure does not get incorporated into the soil,” Royer said.
So Penn State Extension and the USDA Agricultural Research Service are offering opportunities for Conewago farmers to utilize equipment that injects manure into the ground. This minimizes surface runoff of nutrients or volatilization into the air, while directing the manure where it’s needed the most — in the soil for plant uptake.
Penn State Extension educators also have formed a discussion group of dairy farmers in the watershed that meets on a regular basis and discusses topics such as precision feeding, a practice that can reduce the amount of excess nutrients in manure.
Royer warned that it will take patience to assess the project, however.
“We won’t know right away if the actions being taken in the next few years are helping the Conewago,” Royer said.
“There could be a lag time of a decade or more until you see a difference in the stream. It can take 15 years after you plant a forested buffer for trees to mature.”