Springshed Mapping in Support of Watershed Management

Abstract

Fillmore County has been the focal point of dye tracing efforts in Minnesota for several decades. In 1995, a 1:100,000, county-scale springshed map was published. At the county scale, we primarily delineated springsheds greater than 500 hectares. After that project was completed, dye-tracing efforts continued and focused on the South Branch Root River (SBRR) springshed in the western part of the county. At the scale of the SBRR springshed (about 20% of the county), we expanded the boundaries of the large springsheds but also located and refined the boundaries of springsheds that are less than 200 hectares. We found one previously unmapped small springshed (Meyers springshed), documented complex flow boundaries between a large springshed (11. Canfield) and an adjacent small springshed (26. Rainy), and expanded the boundaries of four other springsheds. The small springsheds present a new opportunity for karst watershed research, monitoring and management. The small springsheds are often dominated by one or a few land uses, which permit simpler, more evident identification of the causes of water quality degradation.