City of Portsmouth NH Hosts 165 Attendees for 10th National Keeping History Above Water Conferen

May 17, 2023

Three institutions who have worked together to assess the impacts of sea level rise on Portsmouth NH, including its most historic waterfront neighborhood, hosted the 10th national Keeping History Above Water® (KHAW) conference this week. The City of Portsmouth Planning and Sustainability Department and Water, Wastewater, Stormwater Division of the Department of Public Works along with Strawbery Banke Museum and University of New Hampshire Institute for the Study of Earth, Oceans, and Space welcomed 165 attendees to the three-day conference to explore “Water Has a Memory: Preserving Historic Port Cities from Sea Level Rise.”

Founded in 2016 by the Newport Restoration Foundation to foster a national conversation focused on the increasing and varied risks posed by sea-level rise to historic coastal communities, KHAW® has visited Annapolis, Palo Alto, Des Moines, St. Augustine, Nantucket, Charleston, Salem, Norfolk, Puerto Rico, Trinidad/Tobago and now Portsmouth – a location timed to coincide with the city’s 400th anniversary.

KHAW® programs, conferences, and workshops focus on protecting historic buildings, landscapes, and neighborhoods from the increasing threat of inundation. KHAW Portsmouth 2023 welcomed 27 speakers, including US Senator Jeanne Shaheen, Portsmouth Mayor Deaglan McEachern, author Howard Mansfield, NOAA Senior Advisor for Coastal Inundation and Resilience Mark Osler, UNH climatologist and research professor Dr. Cameron Wake and case studies detailing how municipalities and preservationists from Portland ME to Tidewater VA are addressing the challenges of sea level rise.

The message repeated throughout the conference was, “It’s not a matter of ‘if’ but ‘when’ sea level rise flooding will have increasing impact.

As Howard Mansfield, author of The Habit of Turning the World Upside Down said in his keynote, “We are in daily conflict with the tides. The reassuring sense of continuity is gone and there is no going back.”

NOAA’s Mark Osler reported that while the interconnectedness of water cycles in poorly understood, sea level rise has “inarguably evolved past natural fluctuations.” Billion-dollar climate change weather disasters that in the 1980s happened on average once every four months, now happen every three weeks. He said, “We won’t address these facts with ‘top down’ answers and solutions, they must be defined and sustained locally, with support.”

Many of the speakers provided tools and resources to guide local communities as they take action:  the NOAA Flood Risk Assessment & Application Guide, the NH Coastal Flood Risk Summary: the Scientific Projects and Guidance and the US Senate Advisory Council on Historic Preservation Zoning Atlas. All of the KHAW Portsmouth 2023 presentations will be made available at

In addition to the presentations, the group visited the City’s Prescott Park for an on-site discussion of planned resiliency efforts around the historic 1806 Shaw Warehouse, Strawbery Banke to understand its Water Management Master Plan and the city’s oldest cemetery – the 1671 Point of Graves Burying Ground.

CAPTION: Keeping History Above Water Portsmouth 2023 conference attendees visited the Shaw Warehouse in Prescott Park as week as Strawbery Banke Museum to discuss ongoing resiliency initiatives to protect historic resources from sea level rise.

KHAW conference attendees tour Prescott Park