New Hampshire Coastal Flood Risk Summary

An update of the 2019-2020 New Hampshire Coastal Flood Risk Summary is currently underway and will fulfill the requirements of RSA 483-B:22, which directs NHDES to supervise updates to the 2014 Coastal Risk and Hazard Commission Science and Technical Advisory Panel report, Sea-Level Rise, Storm Surges, and Extreme Precipitation in Coastal New Hampshire, Analysis of Past and Projected Trends , at least every five years. The New Hampshire Coastal Flood Risk Summary is comprised of two parts, including "Part I: Science" and "Part II: Guidance for Using Scientific Projections."

NHDES will collaborate with staff from New Hampshire Sea Grant (NHSG)/University of New Hampshire Cooperative Extension (UNHCE) to facilitate the Steering Committee, and the Science and Guidance Teams, who will review and update the 2019 Part I: Science and 2020 Part II: Guidance reports. In addition, the project team will develop and implement an inclusive engagement and training plan and associated materials.

Updates and notifications about the 2025-2026 Summary Update, public input opportunities and future training events will be posted on this webpage. If you would like to receive notifications, please email jennifer.r.gilbert@des.nh.gov and lisa.wise@unh.edu.

2019 New Hampshire Coastal Flood RIsk Summary - Part I: Science

Published in August 2019, Part I: Science provides a synthesis of the state of the science relevant to coastal flood risks in New Hampshire and includes updated projections of relative sea-level rise, coastal storms, groundwater rise, precipitation and freshwater flooding. “Part I: Science” was developed by a team of scientific advisers from the University of New Hampshire and was reviewed by the STAP and an external panel of regional climate experts from the Northeast Regional Climate Center at Cornell University, Massachusetts Institute of Technology, Purdue University, Rutgers University, U.S. Geological Survey, HydroAnalysis, Inc. and the National Oceanic and Atmospheric Administration.

• Watch Part I: Science Video

2020 New Hampshire Coastal Flood Risk Summary - Part II: Guidance for Using Scientific Projections

Published in March 2020, Part II: Guidance for Using Scientific Projections provides science-based and user-informed guiding principles and a step-by-step approach for incorporating the updated coastal flood risk projections from “Part I: Science” into private, local, state, and federal projects, including planning, regulatory and site-specific efforts. “Part II: Guidance for Using Scientific Projections” was prepared in partnership with the STAP, UNH and NHDES and underwent public review throughout September 2019.

• Watch Part II: Guidance Video

Past Webinar Materials

The NHDES Coastal Program, UNH Cooperative Extension, NH Sea Grant and Piscataqua Region Estuaries Partnership held two webinar trainings on the 2019-2020 New Hampshire Coastal Flood Risk Summary on March 30 and 31, 2020. Links to the webinar slides and recordings, as well as written responses to questions asked during the webinars, are available below.

• March 30, 2020 – Webinar Training for the General Public
  Presentation Slides 
  Webinar Recording
• March 31, 2020 – Webinar Training for Municipal Staff, Boards and Professionals
  Presentation Slides 
  Webinar Recording
• Written Responses to Questions 

Funding for this project was provided by the National Oceanic and Atmospheric Administration Office for Coastal Management under the Coastal Zone Management Act in conjunction with the NHDES Coastal Program.