Coastal Waters

New Hampshire's coastal ecosystems and infrastructure are threatened by the effects of a changing climate.

Aerial view of coastal marshes.
Aerial image provided by UNH.

New Hampshire's coastal ecosystems are threatened by habitat loss, stormwater pollution and the effects of a changing climate. Coastal areas are especially vulnerable to storm surge, flooding and sea level rise, which puts coastal infrastructure, property and habitats at risk. The New Hampshire Coastal Program protects clean water, restores coastal habitats, and helps make communities more resilient to flooding and other natural hazards through staff assistance and funding to 42 coastal towns and cities as well as other local and regional groups. The NHCP is one of 34 federally approved coastal programs authorized under the Coastal Zone Management Act and is administered by NHDES. Learn more about the Coastal Program.

Coastal Flood Risk Summary

The 2019 New Hampshire Coastal Flood Risk Summary is comprised of two parts: a summary of best available science and guidance for how to use the science in decision-making.

aerial photo of coastal flooding in the streets and around homes  Include photo credit: Will Brown 

‘Building a Flood Smart Seacoast’ Workshop Series 

From cracked foundations, totaled cars and destroyed utility systems, recurrent coastal flooding has already inflicted considerable damage in Hampton Beach. This issue is prompting residents to search for ways to protect and continue enjoying their properties for years to come. The Coastal Program, in partnership with the Seabrook-Hamptons Estuary Alliance, hosted the first-in-the-state “Building a Flood Smart Seacoast” workshop series focused on helping property owners make better-informed decisions about how to make their properties more flood resilient.   

aerial photo of erosion on the banks of the shore 

Wagon Hill Farm Living Shoreline Project   

The Town of Durham received a NHDES Coastal Program Coastal Resilience Grant to complete design plans to control erosion problems at Wagon Hill Farm, a popular public recreation spot at the mouth of the tidally influenced Oyster River, through the construction of a living shoreline. This includes saltmarsh habitat and provides space for the marsh to move inland as sea levels rise. Thanks in part to the Coastal Program grant and staff technical assistance, the Wagon Hill Farm living shoreline project was awarded construction funding by the NHDES ARM fund. Construction was completed in 2019.  

aerial view of sand dunes photo credit: Gregg Moore   

Dune Restoration Hampton-Seabrook Estuary 

New Hampshire’s Hampton-Seabrook Estuary has lost 86% of its historic sand dunes since they were first mapped out in 1776. Sand dunes create a natural buffer from storms, shield from flooding and provide habitat. A project initiated by the NH Sea Grant and UNH Cooperative Extension with the support of two Coastal Program resiliency grants continues to restore and protect dunes. The project has focused on replanting and protecting vulnerable and eroded areas in Hampton. Work has included the installation of signs showing where people can access the paths across the sand dunes to the beach and re-vegetation by community volunteers. 

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Did you know?

Did you know?

Docking structures over tidal waters and coastal shoreline stabilization projects are regulated by the Wetlands Bureau. Visit the Wetlands Bureau webpage or check out our fact sheet on Residential Tidal Docks.

Check out our interactive maps!

NHDES has developed a number of online mapping tools to help you find water quality data and information. There are three primary tools: the coastal atlas, the assessment mapper and the lake information mapper.

an image of a lake surrounded by forest

Surface Water Quality Assessment 
  • Spatial extent of assessment units.   
  • Sampling data locations.   
  • Access the Watershed Report Cards (a.k.a. 305(b)/303(d) assessment info).   
  • Run reports to access water quality data summaries used in the assessment process.   
  • View the extent of the EPA's 2017 MS4 General Permit Areas.   

Access the Mapper  

 A beach with buildings in the background.

Find areas for shellfish harvesting and beach going 

The Coastal Atlas is a tool to show information on shellfish bed closures, beach advisories and coastal public access in an easy-to-use format.  

  • Shellfish bed closures.   
  • Beach advisories.   
  • Coastal public access.  

Access the map  

A flat blue lake and blue sky.

Water quality information of individual waterbodies  
  • Trophic studies.  
  • Lake TMDLs.  
  • VLAP reports.  
  • Ice cover history.  
  • Cyanobacteria bloom history.  
  • Watershed-based plans on lakes.  
  • Diagnostic feasibility studies.   
  • Invasive aquatic species information.  

Access the Map  

UNH Coastal Viewer

An online mapping tool that brings coastal resources, hazards-related and spatial data sets within New Hampshire's 42 coastal watershed communities together in one place.