The National Capital Region's long-term water monitoring program funded in part by the Water Resources Division is designed to ensure the National Capital Region's parks possess science-based information needed for effective resource management.

The NCRN Water Resources Program monitors four vital signs: Surface Water Dynamics which includes parameters such as channel area, water velocity, and discharge; Water Chemistry which deals with parameters such as temperature, dissolved oxygen, specific conductance, pH, and acid neutralizing capacity; Nutrient Dynamics which includes ammonia, nitrate, and total phosphorus; and Aquatic Macroinvertebrates. These parameters provide information that characterize a waterbody or stream segment, are fundamental components of monitoring and regulatory programs, and are relatively easy to measure.

The Network is also monitoring the biologic health of streams and has adopted the protocol used by the State of Maryland's Biological Stream Survey Program. Using this protocol, the Network monitors aquatic macroinvertebrates, fish and the physical habitat of streams.

The Water Quality Monitoring Program strives to develop partnerships among other National Park Service divisions, educational institutions, governmental agencies, and private sector organizations such as the Maryland Water Monitoring Council to manage, maintain, and analyze regionally common water resource inventory and monitoring data sets in accessible and usable forms in support of the regions long-term natural resource preservation, protection, and education.