The New Jersey Department of Environmental Protection (DEP) has launched an online tool to help planners, local governments, developers, and residents better understand that extreme precipitation events are increasing, as confirmed by recent studies by the Northeast Regional Climate Center.
The New Jersey Extreme Precipitation Projection Tool allows users to view a range of rainfall depths, with options for frequencies, emission scenarios, and time periods. Due to increasing greenhouse gas emissions and a changing climate, extreme precipitation events are expected to increase in frequency and intensity throughout the century. An improved understanding of these changes could help decision-makers and the public take informed actions necessary to adapt to a changing climate.
The tool allows users to zoom in to local areas and view a depiction of the likely precipitation depth that would occur with various storm scenarios. It also allows users to compare this projection with the values currently published in the NOAA Atlas 14 reference report. The tool is being launched during Earth Week.
“While Earth Week is certainly a time to celebrate our planet and our environment, it is also a time to commit to making hard choices to adapt to a changing planet and become more resilient,” said Environmental Protection Commissioner Shawn M. LaTourette. “This Extreme Precipitation Projection Tool is an investment in our planet by helping to open our eyes to the realities of climate change-induced flooding and helping us make better decisions on how and where we build. This tool will help all of us make informed choices to ensure that development is able to withstand the test of a changing planet.”
The tool incorporates the important findings detailed in two New Jersey-specific studies by the Northeast Regional Climate Center at Cornell University and in partnership with DEP. The studies, released in November, found that extreme precipitation events have been increasing for the past 20 years and are going to continue to increase throughout the end of the century.
The studies found that precipitation expectations that long guided state policy, planning, and development criteria, and which rely upon data obtained through 2000, do not accurately reflect current precipitation intensity conditions. By including additional data through 2019, extreme precipitation amounts are 2.5 percent higher, and some parts of the state have seen a 10 percent increase above the outdated data.
The studies also found that precipitation is likely to increase by more than 20 percent from the historical baseline (1950-1999) through 2100, and projected changes will be greater in the northern part of the state than in the southern and coastal areas, with upper likelihood projections for some northwestern counties seeing the greatest increases, by as much as 50 percent.
DEP will be using the Extreme Precipitation Projection Tool in planning and decision-making processes and encourages local government agencies, planners and developers to use the tool when assessing needs for flood hazard and stormwater management permits.
