Emily Keys Innes
by Emily Keys Innes
The effects of climate change and sea-level rise are changing how we plan for and build in coastal areas. It affects development at all scales, including individual buildings and lots and neighborhood, municipal, and regional projects. The development concerns are two-fold — storm surges and rising tides — and both are the focus of professional services firms serving coastal cities and towns.
Scientists around the world agree that seas are rising now, and that climate change will affect the number and intensity of storms. No agreement has been reached on the rate or level, but recent reports in the New York Times suggest that a faster-melting Greenland ice sheet may negatively alter earlier estimates. Planning for higher daily tides requires a different set of strategies than planning for more intensive storm surges. If sea levels rise at a faster rate, then mitigation strategies will require major infrastructure investments or moving development away from coastal areas.
The social, political, and financial implications of coastal resiliency strategies are only now beginning to be assessed, but in the meantime, design and building professionals should become aware of the probable impacts and the range of strategies available to best serve their clients.
Local and state governments and utility companies must be involved in planning for resiliency at the neighborhood, municipal, and regional levels. Infrastructure improvements such as coastal roads, sea walls, levees, jetties and piers, and regional utility systems will need to be reengineered to meet new requirements.
Resiliency strategies will require cooperation from local and regional governments, insurance companies, financial institutions and investors, and property owners and developers. Recent updates to FEMA maps have caused pushback from property owners who found that their insurance premiums soared as a result. Proposals to not allow certain areas of New Orleans to be rebuilt after Hurricane Katrina created serious controversy. The Boston/New England chapter of the Urban Land Institute has created a public discussion on the implications of sea-level rise, and communities throughout New England, including Boston and Quincy, are planning now for future impacts.
How can you protect your development interests now? In the short term, strategies will focus on the individual building or site. Existing buildings in danger of flooding can be retrofitted to protect materials and systems from floodwaters, mold, and the corrosive effects of saltwater. Aqua fence flood protection barrier system is one example of a short-term strategy that can be installed in advance of a storm event.
Other solutions include design strategies in new development that mitigate the effect of higher tide levels and storm surges. Site plans that include landscape treatments and hardscapes that allow the tide and/or floodwaters to interact with the site will likely be more effective over time than those that seek to exclude water.
Building designs should locate mechanical systems and utility connections, including the electrical vault, to higher floors. Ground floors in areas subject to frequent flooding should have uses that can be temporarily interrupted and materials that are resistant to damage from floodwaters. Parking levels at ground level or below should be designed to allow water to flow in and out. These are examples of working with water rather than excluding it.
The amount and cause of sea-level rise varies in each region — in some areas, the land itself is subsiding because of the structure of existing soils or because of groundwater being removed to support development. The bigger question is, just how high will the water rise? The answer is a function of time, planetary temperature, location, and the rate at which the glaciers and the Antarctic and Greenland ice sheets melt.
Emily Keys Innes, LEED AP ND, is an urban planner at The Cecil Group in Boston.
