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October 13, 2022


Online Resources for Inland Flood Protection Rule Available; Virtual Engagement
Sessions Announced for the Week of October 17

Sessions to Educate Stakeholders on Updated Rainfall Data, Necessary Changes in Elevation
and Flood Hazard Standards to Protect Public Safety 

Following an initial stakeholder engagement and feedback on the New Jersey Department of Environmental Protection’s plan to propose an Inland Flood Protection Rule to better protect New Jersey residents, their property, and communities from dangerous flooding that continues to worsen due to increased precipitation resulting from climate change, the Department will hold a pair of engagement sessions to provide an additional opportunity for attendees to better understand the basis, specifics and implications of riverine flood threat protections statewide as well as engage in conversation regarding considerations in implementing changes in elevation and flood hazard standards to protect public safety. The goal is to ensure that investments in new and reconstructed development are more resilient and better protect the state from worsening flooding events as experienced by many New Jersey communities when the remnants of Tropical Storm Ida slammed into the state in September 2021.

Two public engagement sessions will be as follows:

For more information on signing up for the sessions, visit


Tragically, flooding caused by Ida killed 30 people in New Jersey. This storm event came at the tail end of a series of intense weather events during summer of 2021. With patterns of increasingly intense storms becoming more routine due to climate change and current state and Federal Emergency Management Agency (FEMA) flood standards being based on backward-looking, 1999 precipitation data, New Jersey residents are at risk of being unprotected and potentially uninformed about flood risks from climate-influenced precipitation, including unmapped areas that now routinely flood.

In an effort to close these severe data gaps and provide a reliable scientific basis for regulatory adjustments, the DEP commissioned New Jersey-specific studies that confirm precipitation has increased in the state over the past 20 years and will continue to increase through the end of this century. The peer-reviewed studies, released in November 2021, were performed by the Northeast Regional Climate Center, a partner of the National Oceanic and Atmospheric Administration (NOAA).

Key findings show that:

  • Precipitation amounts that long guided state policy, planning and development criteria relied upon data obtained through 1999 and did not accurately reflect current precipitation intensity conditions. Extreme precipitation amounts are 1 percent to 15 percent higher now than the 1999 data suggests. Therefore, the 1999 data previously in use is outdated and not reflective of current precipitation.
  • Precipitation during the 100-year storm is likely to increase by 23 percent to 50 percent above the 1999 baseline by 2100. These numbers represent the upper end of the likely range as defined by the Intergovernmental Panel on Climate Change (IPCC). Projected changes will be greater in the northern part of the state than in the southern and coastal areas.

The Inland Flood Protection Rule would require applicants for certain development permits to use precipitation data generated by these studies when calculating peak flow rates of streams and rivers for permits under the Flood Hazard Area Control Act Rules, N.J.A.C. 7:13, as well as when proposed development triggers compliance with the DEP's Stormwater Management rules, N.J.A.C. 7:8. Municipalities will also need to utilize the precipitation data generated by these studies when considering stormwater designs for residential development. Municipalities will need to update their local ordinances before these new requirements will apply to non-residential developments at the municipal level.

Design elevations for structures in riverine (or fluvial) areas will be two feet higher than currently indicated on DEP flood maps and three feet higher than indicated on FEMA maps. The rule changes will apply to new development and redevelopment and does not apply to existing development.

In connection with the Inland Flood Protection Rule, to aid the public to gauge flood risk and provide a visual approximation of regulatory jurisdiction on specific parcels, the DEP has launched a flood indicator tool. While the tool does not provide a definitive demonstration of regulatory jurisdiction or calculate actual risk, it can be useful in assisting property owners or prospective property owners on potential risk and, by referencing the 500-year flood extent, approximate DEP’s regulatory jurisdiction and flood risk. Armed with this information, property owners may then decide to take additional steps to determine actual risk, which is dependent on site-specific conditions.

Stormwater grant funding is available help local officials understand and improve local stormwater management, thereby reducing flooding and improving water quality. The deadline to apply for the Stormwater Utility Technical Assistance Grant is November 1, 2022.

Flooded Streets in Bound Brook photo

Photo: An aerial view of flooded streets in Bound Brook resulting from the remnants of Tropical Storm Ida