Rivers and Lakes

Monitoring and reporting on the condition of New Hampshire’s surface waters.

Water flows over a rocky stream bed in the forest.The primary factor that impacts the water quality in rivers and lakes is what drains from the land into the water. All of the land that drains to a particular body of water is called its watershed. Within every watershed, water runs to the lowest point on that landscape - a stream, river, lake, estuary or ocean. On its way, the water travels across farm fields, forestland, parking lots, highways, city streets and backyards. Watershed management incorporates monitoring, public participation, planning and restoration.

Learn more about watersheds!

NHDES has multiple programs responsible for monitoring the water quality in the state’s lake and rivers, and protecting these water bodies. NHDES also relies on citizen science volunteers to fulfill its mission.

a river winds through snowy banksProtecting our natural and cultural resources 

The Rivers Management and Protection Program strives to protect the outstanding natural and cultural resources associated with the designated rivers of New Hampshire. 

The Lakes Management and Protection Program strives to protect the health and water quality of lakes and ponds while balancing its multiple uses. 

a lake surrounded by treesMonitoring the quality of our rivers, streams, lakes and ponds 

New Hampshire has over 800 lakes and ponds and approximately 19,000 miles of rivers and streams. NHDES is responsible for monitoring the quality of these waterbodies and reporting on their condition. There are several well-established programs designed to accomplish these objectives.  

Learn more about river and lake monitoring  

 two volunteers collect a water sample from Country Pond

Volunteer Lake Assessment Program 

The Volunteer Lake Assessment Program (VLAP) engages citizen volunteers to monitor lake water quality and play an active role in watershed management through science, training, reporting, community education and outreach.  

Learn more about VLAP  

the Lamprey River flows through a lush forest

Ensuring we have enough water to support people and wildlife 

The Instream Flow Program ensures that New Hampshire’s 19 designated rivers have enough water to support the needs of people and aquatic life.

Learn more about instream flow  

Water Quality Standards

people take water samples off of the side of a boatEvery two years, NHDES produces an Integrated Report describing the quality of New Hampshire’s surface waters and an analysis of how well the waters provide for the protection and propagation of a balanced population of shellfish, fish and wildlife, and allow recreational activities in and on the water. Some waters are categorized as impaired and require the creation of a Total Maximum Daily Load (TMDL): the calculation of the maximum amount of a pollutant that a waterbody can receive or contain while maintaining the water quality standard for its designated use. Learn more about water quality assessments!

The Water Quality Standards Information Exchange exists to facilitate public input, solicit advice and provide a forum for the discussion of focused surface water quality standards issues.

Water Quality Certification

The purpose of the Water Quality Certification program is to protect surface water quality and uses (such as swimming and aquatic life) by ensuring compliance with the state’s surface water quality standards.

How is the water?

Want to know about your waterbody? Check out our interactive map! It allows you to: see where sampling data were collected; access Watershed Report Cards; and run reports of water quality data summaries.

Watershed Assistance

The Watershed Assistance Section works with local groups and EPA to improve the state’s water quality at the watershed level by implementing the Nonpoint Source Management Program Plan.