Total Maximum Daily Loads (TMDLs) are a regulatory management strategy to partition waste load allocations (WLAs) among various dischargers to keep concentrations within limits in the receiving water body. They are a step beyond the National Pollution Discharge Elimination System (NPDES) permitting system for point source discharges by incorporating a broader perspective. Water quality management can be improved by using a comprehensive watershed approach that reflects cumulative effects of activities within a drainage basin.