The United States Environmental Protection Agency (USEPA) requires the Minnesota Pollution Control Agency (MPCA) to carry out the Total Maximum Daily Load Program (TMDL) in the state of Minnesota. Minnesota has an abundance of lakes and river reaches, many of which will require a TMDL study. In an effort to expedite the completion of TMDL projects, the MPCA has decided to construct watershed models. These models have the potential to support the simultaneous development of TMDL studies for multiple listings within a cataloging unit or 8-digit Hydrologic Unit Code watershed.