Phone: 603-778-0885
Fax: 603-778-9183

High Water Mark Initiative

The Rockingham Planning Commission (RPC) has worked with the municipalities of Portsmouth, Rye, Hampton, and Seabrook, and the Department of Natural and Cultural Resources (DNCR) NH State Parks to design, coordinate, and implement a community-based High Water Mark Initiative (HWM) and identify flood adaptation and resilience actions. One goal of the High Water Mark project is to install high water markers in each municipality.

The HWM project has four main goals:

  1. Install permanent markers and signage in strategic locations showing the elevation and causes of flooding from past and/or future events (e.g. future projected sea-level rise) and climate related conditions.
  2. Provide information on flooding and flood risks provided to large numbers of local residents and visitors from the Seacoast region.
  3. Engage municipal decision makers engaged in discussions about flood risks in their community and what their community is doing and can do to address those risks.
  4. Prepare Case Stories about how the project participants are responding to flood risks and actions they’ve taken and intend to complete in the future.

Follow the links below to the project materials and tools.


High Water Mark Signs at Seabrook (Browns Lobster, River Street boat launch), Hampton (Transfer Station), Rye (Route 1A/Wallis Road at Parsons Creek), Odiorne State Park Boat Launch and Strawbery Banke (Mechanic Street parking lot)

Case Stories about climate adaptation and resilience accomplishments for Portsmouth, Rye, Hampton and Seabrook

Climate Adaptation and Resilience Checklist and Guidance


Follow RPC on Facebook or Twitter and watch for photos taken at the High Water markers using #highwatermarknh.


What can you do to spread the word about flooding?

Take a photo with a High Water Mark sign and post it to social media using the hashtag #highwatermarknh.

This project was funded, in part, by NOAA's Office for Coastal Management under the Coastal Zone Management Act in conjunction with the NH Department of Environmental Services Coastal Program.