Paper No. 112-8
Presentation Time: 9:00 AM-6:30 PM
WHAT IS CAUSING WATER QUALITY AND STREAMFLOW DECLINES IN SAGANING CREEK WATERSHED, MI?
The Saganing Creek Watershed (MI) is a small watershed (78 km2) with a low order stream that drains to Saginaw Bay; declining water quality and stream discharge have been reported during the past years, however, the cause(s) have not been fully examined. Saganing Creek has significant value to the Saginaw Chippewa Indian Tribe as a cultural site and for its historic fish populations; as recently as 30 years ago, the Saganing was a highly popular smelt dipping stream. Since this time, flow in the creek has ceased during several summers, turning the creek into separate stagnant pools. Algal blooms are common and measures of ecological health (including invertebrate studies) have indicated significant water quality impairment. To better understand the cause(s) behind the decline of Saganing Creek, a study was undertaken in 2015 assessing the sources of flow and nutrients during the summer season. Seepage meters were used to estimate groundwater discharge and nutrient loading, agricultural drains were surveyed and sampled, and streamflow and water quality were measured along the creek. These results were combined with historic land use data, agricultural census data, and results from previous ecological monitoring studies to develop a conceptual understanding of flow and water quality declines in the creek. Results show that changes in the agricultural drainage system within the watershed may have altered timing and magnitude of stream discharge as well as affected nutrient loading. Groundwater discharge to the creek was observed even during times of flow stagnation; the amount may not be sufficient during baseflow conditions to maintain flow in the creek. Further study is necessary to quantify additional potential sources of N and P to the system (such as septic waste) that may be significant. It is vital to the rehabilitation and conservation efforts in the Saganing Creek Watershed that the hydrology and nutrient cycling is better understood.