In order for Best Management Practices to remain effective, they must be maintained and monitored for effectiveness. For a residential BMP such as a gravel infiltration trench, monitoring is visual observation done by the homeowner during a storm to see if the trench is still infiltrating water. Gravel infiltration trenches typically have a life span of eight to twelve years before they need maintenance. Maintenance in this example is the homeowner removing sediment and debris that accumulates in the trench to ensure the trench's effectiveness.

For a commercial site, monitoring may include storm water quality sampling to ensure that water leaving pre-treatment falls within TRPA's guidelines for surface or groundwater discharge. Maintenance in this example would include the commercial property owner having a storm water pollution prevention plan which incorporates routine servicing of the storm water pretreatment system and the parking areas.