The Boston Planning & Development Agency plans to roll out a new coastal flood zoning overlay that will cover every parcel with a projected 1 percent annual chance of flooding in 2070. Image courtesy of the city of Boston

As thousands of activists rally at today’s Climate Strike rally at Government Center, city hall planners are preparing a new set of rules for development in Boston neighborhoods that are vulnerable to climate change-induced flooding.

The coastal flood resilience design guidelines approved by the Boston Planning & Development Agency last week will be the basis for a new overlay zoning district governing both new development and retrofits of existing properties.

“We wanted to get this out to provide general guidelines and what expectations are going to be moving forward in terms of what we require,” said Chris Busch, the BPDA’s assistant deputy director for climate and environmental planning.

The BPDA already requires developers of large projects to fill out a resiliency checklist, but zoning code does not reflect such strategies.

The new overlay could be adopted in approximately six months, Busch said. It will apply to properties with a 1 percent annual chance of flooding in 2070, when researchers predict Boston Harbor sea levels will have risen by 40 inches. That would put large portions of neighborhoods including the South End, East Boston and the Seaport District at risk.

The guidelines provide a range of options for property owners to elevate and fortify properties, such as building structures on pilings and elevating mechanical equipment to upper floors.

The zoning overlay will include new building height and density rules that don’t penalize developers for adopting resiliency strategies such as elevated structures, Busch said.

Waterfront developers have begun to voluntarily adopt aggressive flood-proofing strategies. Lendlease’s 478-unit Clippership Wharf condo and apartment complex that opened last month in East Boston placed residential floors 14 feet above current high tide levels and installed a living shoreline, while equipping ground floors with deployable flood gates.

New Boston Building Rules Will Require Resiliency

by Steve Adams time to read: 1 min