Hull is a narrow, low-lying peninsula located 12 miles south of Boston. This town of approximately 11,000 residents covers 33 miles of densely developed shoreline separating Hingham Bay from the Atlantic Ocean. The community experiences regular damages and flood claims from northeasters and is also vulnerable to hurricanes.
To address current and future storm damage impacts, the town sought to improve standards guiding development and redevelopment and to enhance education and outreach regarding the risks associated with coastal storms and sea level rise.
Approach and Results
The Hull StormSmart Coasts pilot project resulted in the development of two innovative tools that can be used as models in other coastal communities:
- Freeboard Incentive: In September 2009, the Hull Board of Selectman unanimously voted to enact the state's first freeboard incentive program to encourage the elevation of flood-prone buildings above currently predicted floodwater levels to account for future coastal storm events and sea level rise. Through this freeboard incentive program, the town seeks to protect the health and safety of citizens, prevent property damage, and reduce costly emergency services. Hull's Conservation Agent worked with CZM and the town's Building Commissioner to develop the freeboard incentive, which enables the Building Department to offer a credit up to $500 for permit fees to builders and homeowners who elevate new and renovated structures at least two feet above the highest federal or state requirement. (Buildings in A and V zones need to be elevated at least two to four feet above the base flood elevation, respectively, to meet the freeboard requirements.) In the first four years of the program, 26 of 30 permit requests for new construction or to elevate existing development included two or more feet of freeboard and qualified for the credit. An added benefit for property owners is significant discounts to flood insurance premiums. Many homeowners are building higher than required to maximize flood insurance savings and provide added protection from coastal storms. In May 2011, Hull's zoning bylaw was amended to address height restrictions and better accommodate freeboard. The Zoning Board of Appeals may now grant Special Permits to elevate existing buildings for flood protection. These building may exceed the height limit to provide a maximum of four feet of freeboard.
- Storm Surge Visualization Tool: The StormSmart Coasts team also developed a three-dimensional (3D) visualization tool to improve local understanding of the impacts of flood events and sea level rise. Through a contract with Applied Science Associates, photorealistic 3D models were developed for seven Hull facilities that are critical to public safety, health, and welfare. High-resolution topographic data were used to create the 3D models of five flooding scenarios at seven critical facilities. The flooding scenarios defined by the StormSmart Coasts team include:
- Base Flood Elevation (BFE) determined by the Federal Emergency Management Agency and shown on Flood Insurance Rate Maps
- BFE + current sea level trend (0.3 meter [m] or 1.0 feet [ft])
- BFE + low rate of sea level rise (0.5 m or 1.6 ft)
- BFE + moderate rate of sea level rise (1.0 m or 3.3 ft)
- BFE + high rate of sea level rise (3.0 m or 9.8 ft)
The town of Hull received the National Oceanic and Atmospheric Administration (NOAA) 2010 Walter B. Jones Memorial Award for Excellence in Local Government for their innovative work on this project and their outstanding efforts at local management of coastal hazards.
See Using Freeboard to Elevate Structures above Predicted Floodwaters for related information on freeboard. The NOAA CanVis tool provides another way to develop realistic storm surge visualizations using photographs.