NHARPC CORNER: Rising Seas: Impacting More than Just the Ebb and Flow of the Tides

Julie LaBranche, Rockingham Planning Commission, and Kyle Pimental, Strafford Regional Planning Commission

"The sea, the great unifier, is man's only hope. Now, as never before, the old phrase has a literal meaning: we are all in the same boat."   - Jacques Cousteau

Living at the Water’s Edge

It’s human nature to want to seek out and be close to bodies of water. A quick Google search captures hundreds of articles that attempt to explain why humans are so drawn to the water. Yet, what may have started as a primitive need for survival has evolved into a “way of life,” and shoreline development is now one of the primary economic drivers in coastal states. Based on sale prices driven by the real estate market, assessments of waterfront properties have risen steadily in recent years, and the revenues they generate are substantial. Coastal municipalities also benefit from tourism, which generates additional revenue, employment, and business opportunities. And let’s not forget the psychological factors. People living next to, or even within the sight of, water have reported a variety of positive benefits such as improved mental health and physical well-being. It’s not surprising, then, that nearly 40 percent of the American population lives in coastal areas.

Although demand for these properties is high, owners of homes and businesses in coastal areas are faced with the increased risk of flooding associated with sea level rise and storm surge. The NH Coastal Risk and Hazards Commission Report (2016) and Science and Technical Advisory Panel Report (2014) include the following key findings:

  • Sea levels in New Hampshire are expected to rise between 0.6 and 2.0 feet by 2050 and between 1.6 and 6.6 feet by 2100.
  • Today’s extreme storm surge events will have a significantly greater inundation extent and destructive impact due to higher sea levels.

Given these future projected conditions, coastal municipalities, home owners and businesses are faced with making decisions today that will ensure protection of critical assets and resources into the future.

Employing a New Paradigm for Our Coasts

The New Hampshire Seacoast has been fortunate in recent years to have been spared the ravages of extreme storms such as Hurricane Irene and Superstorm Sandy. Most recently, winter storm Grayson on January 3, 2018 caused blizzard conditions and extensive coastal flooding throughout New England. One needs only to have read the headlines and numerous articles about the devastation they caused to appreciate the challenges communities faced in rebuilding. In the aftermath of such storms, many communities employed innovative solutions to create more resilient coastlines, including restoring natural shoreline functions and applying more stringent flood protection requirements for both rebuilding and new development. These types of strategies protect against storms today as well as future impacts from long-term sea-level rise.

Examples of recent local actions to increase resilience to a changing climate include:

  • Master Plan Coastal Hazards and Climate Adaptation Chapter - adopted by Seabrook and Rye; in process by Dover, Greenland and Stratham.
  • “Freeboard” requirement to elevate structures above the base flood elevation - adopted by Hampton, Dover, Durham and Rye (pending 2018 town meeting vote).
  • Vulnerability assessment maps and data incorporated into Hazard Mitigation Plan updates: Rollinsford, Durham, Newmarket, Dover, Portsmouth, Rye, North Hampton and Hampton Falls.
  • Sand Dune Restoration in Seabrook and inland shoreland restoration projects- in Durham and Dover.

Recognizing that they do have choices, many communities have taken steps to ensure their decisions of today will protect them against flooding in the future. New Hampshire’s coastal municipalities are among those rethinking their long-term vision for their coastal areas. The catalyst in some cases is the “sunny day” flooding many regularly experience from the highest annual and seasonal tides and the increased flooding that occurs during moderate storms. These conditions could become the new normal as sea levels rise and precipitation increases. How would life change if our coastal areas flooded twice daily at high tide? No doubt our quality of life would be diminished, as business continuity, employment, and tourism decline and the cost of flood insurance rises.

With funding from federal agency partners, a handful of New Hampshire municipalities launched climate adaptation initiatives focused on planning, regulatory reform, assessment of local flood impacts, and community outreach. These actions have helped gain public support to enact regulatory standards for coastal development, invest in infrastructure improvements, and fund technical assistance and staffing needed to implement new programs and policies.

Envisioning the Future: Science and Sound Planning

Guided by the best available science, municipalities recognize that incremental steps are needed now and in the long term to address impacts from coastal flooding and increased precipitation. A series of actions can help municipalities respond to changing conditions while providing “no regrets” benefits to the community. These actions include preservation and restoration of shoreline ecosystems and their services, infrastructure that can be adapted to changing conditions, and prohibitions on new development in the areas at highest risk of flooding.

Municipalities have the power today to ensure the viability of their populations in the future. Let’s dare to focus on the big picture through the lens of climate change. New Hampshire’s coastal municipalities have already shown a willingness to embrace innovation to solve the complex problems posed by sea level rise and the possibility of a future with increased coastal storm activity. Whatever we do to improve our resiliency in vulnerable areas today will benefit our future throughout the state.

Julie LaBranche is a Senior Planner with the Rockingham Planning Commission and can be reached by phone at 603.658.0522 or by email at jlabranche@rpc-nh.org.  Kyle Pimental is Principal Regional Planner with the Strafford Regional Planning Commission and can be reached by phone at 603.994.3500 or by email at kpimental@strafford.org.