Water Quality in the Saint Joseph River Watershed

The St. Joseph River is fed by a 694,400-acre watershed that drains parts of Michigan, Ohio, and Indiana and serves as a source of domestic water for more than 200,000 residents in the City of Fort Wayne and surrounding area (Fig. 1). The St. Joseph River Watershed Initiative Partnership (SJRWI) was formed in 1996 in response to the detection of atrazine in Fort Wayne’s drinking water. Since then, the Initiative has worked tirelessly to educate stakeholders about water quality and to encourage the installation and use of conservation best management practices. The SJRWI and its water quality sampling program are recognized by water quality experts across the nation, and even internationally, for excellence.

Since 2007, Dr. Gillespie and a crew of graduate students have managed the water quality monitoring program for the SJRWI. His lab monitors and collects water samples weekly from April through October at 24 sites over the entire 700,000-acres (Figures 2 and 3). In the field technicians record measurements, such as temperature, dissolved oxygen, pH, and turbidity (Fig. 4). Additionally, they collect samples for analysis of nutrients, herbicides, and E. coli. Over the past seven years, Erin McKinney (M.S. Biology, 2012) has been the lead technician for the monitoring program, including authoring annual reports. Data collected from the water monitoring program are used primarily to support watershed management plans to inform decisions about implementation of programs to improve water quality in targeted areas of sub-watersheds. Data are also provided to federal (USGS) and state (IDEM) agencies to support their databases.


Figure 2: The David Link drainage ditch (Site 142) typifies a headwater stream in an agricultural landscape of the Cedar Creek watershed, near Auburn, IN. These ditches comprise up to 80% of headwater streams in northeast Indiana. Note the channelized morphology and lack of adequate riparian habitat. Additionally, these ditches receive non-point source runoff from drainage tile outlets during rain events and delivere the load to Cedar Creek- running through the trees in the background.


Figure 3: The East Branch of the West Fork of the St. Joseph River in Hillsdale County, MI (Site 155) is a headwater stream whose habitat and water quality are suitable as a reference study site. The East Branch drains some agricultural and residential acreage, but water chemistry and habitat metrics show a relatively high-quality stream when compared to drainage ditches that typify headwater streams in agricultural landscapes.


Figure 4: Median turbidity at the confluence of Cedar Creek and the St. Joseph River (Site 100). The Cedar Creek watershed is the largest contributor to the St. Joe. The median comprises 16-30 samples from a single collection site. The “REF” line is a benchmark for turbidity. The highest quality streams have turbidity values below this metric. Note the apparent decreasing trend since 2008.


Dr. Gillespie has actively reported on water quality in the St. Joseph River Watershed through presentations to professional and public groups. One recent report, “State of the River- 2011” provided the City and resource managers with the conclusion that the St. Joseph River is impacted primarily by non-point source pollutants, such as suspended solids, nutrients and pathogenic microorganisms. Working with the Initiative, City of Fort Wayne, and Allen County Dr. Gillespie’s team provides important support to resource managers, and other stakeholders who need scientific information to improve water quality.