In a coastal city such as Boston, how can we balance the immediate pressure for new development with an understanding that, in the long-term, the waterfront will be subject to regular flooding? The key lies in linking a vision for the future with the ability to incrementally finance and build today.
We addressed this in a recent design competition intended to make Boston’s Fort Point neighborhood resilient in the face of sea-level rise and other climate change impacts. For inspiration we looked to the policy framework employed by Boston’s successful Harborwalk, which requires developers to integrate into new construction a segment-by-segment build-out of a contiguous pedestrian promenade along Boston’s 46-mile waterfront. Since 1984 this requirement and publicly constructed segments have completed more than 80% of the path system.
Our proposal, “Resilient Linkages,” consists of planning policies that raise resiliency requirements and incentivize responsible building — establishing, today, the supporting infrastructure for the elevated street grid of tomorrow. Specifically:
- All new development will be required to build elevated terraces and structural piers 14-16 feet above current street levels; in time (unless we are successful at reversing the current trajectory), as sea-level rise becomes undeniable and investments in resiliency gain public support, the city will provide the final road panels that link together these structural supports to create a fully-functional, elevated street grid and utility network.
- Existing buildings would be allowed to add floors or sell air rights to cover the cost of flood-proofing lower levels.
- All new development must be constructed to survive periodic and eventual inundation of the lower levels; these sacrificial lower floors will be compensated in the form of an additional height allowance above existing limits.
- Additional height incentives are provided for buildings that provide public plazas at the elevated street level, produce renewable power or create affordable housing.
- Existing ground-level open space will over time convert to waterparks that accept high tides or storm surges, or collect and store rainwater.
Our proposal consists of much more — included in the accompanying diagrams — but at its heart is our belief that the best resiliency strategy embraces mounting sea levels through public and private investment in responsive infrastructure. As the Harborwalk has shown us, long-range benefits can result from the sum of incremental actions over a long period of time.
Banner image courtesy of Oliver Clarke/Flickr.
All other images courtesy of NBBJ.Follow nbbX