Degradation of natural waters has become an issue of national concern over the past fifty years. In Minnesota, water quality in lakes and rivers is prone to rapid deterioration due to increased phosphorus loading resulting in an amplification of nuisance species of aquatic plants and organisms. Big Detroit Lake in Becker County, MN, is a large recreational lake that is threatened by declining water quality. Several national, state, and county organizations have come together to study the watershed surrounding this lake in the interest of taking preventive measures to protect the lake from further degradation. Through preliminary studies, it was found that Rice Lake Wetland contributes significant amounts of phosphorus via a manmade ditch to Big Detroit Lake. The objectives of this study were to describe the local hydrology around and within the wetland, establish a generalized mass balance of phosphorus for the wetland, define phosphorus loading in the ditch system as a result of temporal, meteorological, and chemical changes, and define the major processes controlling the discharge of total and ortho phosphorus.