ANALYSIS OF STREAM TEMPERATURES IN EAST INDIAN CREEK, WABASHA COUNTY, MINNESOTA

Brook trout populations have been rebounding in southeastern Minnesota streams since the 1970s. Brook trout prefer cool, stable stream conditions, which can be supplied by groundwater inflow to streams. As a part of a Minnesota Environmental Trust Fund sponsored project, the Minnesota Geological Survey in cooperation with the Center for Transformative Environmental Monitoring Programs (CTEMPS) studied two thousand meters of the headwaters of East Indian Creek in Wabasha County, Minnesota to relate geology and hydrology to brook trout habitat. Areas of groundwater inflow to the stream can be identified to help understand trout habitat. A fiber optic distributed temperature sensor (DTS) cable placed along the streambed of the study reach continuously senses temperature using Raman light scattering. Data was collected every five minutes for 4 weeks at one meter resolution. This study involves analysis of calibrated temperature data to identify stream temperature trends based on time of day and location. Results are used to identify areas of groundwater inflow and other possible controls on stream temperature.