A WRE must provide the vision and path to achieve the water quality levels necessary to support existing designated uses under Maryland's water quality standards through nonpoint source management and wastewater treatment. The WRE should also manage stormwater sufficiently to protect stream habitat. The implementation of the comprehensive plan's vision is realized through zoning and subdivision regulations. Suitable stormwater treatment involves two key considerations:

• The programmatic aspects of effective stormwater management, and
• ​The assessment of potential impacts of proposed land use changes on nonpoint source loads to state waters.

Limited assimilative capacity of receiving waters can inhibit or stop planned development within a watershed. This is the case whether assimilative capacity is exceeded as a result of increased point source loads, as a result of nonpoint source loads from new development or as a result of a combination of the two.

The National Pollutant Discharge Elimination System (NPDES) and State Stormwater Management programs do not directly regulate nonpoint source pollution loads from development or associated septic systems outside of areas served by water and sewer, which are typically also areas outside of Priority Funding Areas. For this reason, it is incumbent upon the WRE and land use management programs to properly manage and regulate development outside of PFAs. By doing so, local government can manage nonpoint source pollution loads, commensurate with the assimilative capacity of state waters. Failure to do so reduces assimilative capacity​ and may hasten the time when constraints must be placed on planned development in a watershed through the NPDES program.