With its four tornadoes, 30 deaths, intense rainfall, and flooding, Tropical Storm Ida in September 2021 confirmed what many authorities already knew: New Jersey’s flood maps and building restrictions are out of date. In October 2022, Gov. Phil Murphy and the state Department of Environmental Protection (DEP) proposed an Inland Flood Protection Rule (IFPR) that would require higher elevations for at-risk housing construction and reconstruction: 2 feet higher than indicated on DEP flood maps and 3 feet higher than indicated on Federal Emergency Management Agency (FEMA) maps.
Current standards are based on historical flooding data compiled 20 to 40 years ago and don’t take climate change and increasing precipitation into account. “Tropical Storm Ida caused flooding as much as 3 feet or more above FEMA’s 100-year flood elevation,” the proposed rule notes.
Hundred-year floods in parts of northwest New Jersey could involve as much as 50% more rainfall than current models allow, NJ officials say.
In-house flood maps at the DEP do allow for stiffer building restrictions based on worsening flooding, but the FEMA maps contain no such safety factor, which is why the state is calling for different building elevations based on which set of flood maps are used. “The DEP finds that the factor of safety found in FEMA mapping needs to increase to a total of 3 feet to adequately protect the public from extreme flood events.”
IFPR concerns river flood zones, not oceanfront floods caused by sea level rise or severe storms, which are serious problems, too. In January 2020, Murphy ordered the DEP to incorporate sea level rise into land use permitting decisions, although the DEP missed its deadline for action this year. Meanwhile, the NJ Business and Industry Association, a powerful business lobby, complained that to them the proposed building standards seem excessively strict.
The DEP is accepting public comment on the IFPR through February 3, 2023, with a public hearing set for January 11, 2023. It is essential that members of the NJ Chapter submit public comments and help support this important flood protection effort.
Resources
Inland Flood Protection Rule: bit.ly/3O5uzSp
New Jersey Protecting Against Climate Threats, NJPACT: bit.ly/3E8n7S2
NJBIA response: bit.ly/3V8xhti