Historic Preservation and Climate Change

Climate change is increasing New Jersey communities’ exposure to increasingly frequent flooding. The  New Jersey's Rising Seas and Changing Coastal Storms: Report of the 2019 Science and Technical Advisory Panel  notes that, along the coast, high-tide flooding events are increasing. The baseline flooding for coastal storms will increase because of higher sea levels. The  2020 New Jersey Scientific Report on Climate Change  advises that communities should prepare for more extreme rainfall, with corresponding increases to riverine and urban flooding.

Historic preservation allows communities to protect and maintain buildings and areas for their architectural value, archaeological value, or association with significant events. Riverine and coastal flooding place NJ historic and cultural resources at risk. Using data from the  NJ State Historic Preservation Office , this StoryMap will examine historic preservation assets exposed to current and future flood hazards, including:

1. The Walt Whitman District in Camden
2. Historic private homes in Beach Haven
3. The historic commercial and residential districts in Cape May
4. Identified historic resources in Penns Grove
5. The Hoboken Historic District in Hoboken
6. Historic mill districts in Tewksbury

The data include National Historic Landmarks, designated, identified, listed, or eligible for designation as historic resources, bringing economic, social, and cultural value to a community. Identified resources are those evaluated through statewide cultural resource survey efforts. Listed resources are on the New Jersey or National Registers of Historic Places. Eligible resources have formal determinations of eligibility for the Registers. Locally designated resources are designated by municipalities as local landmarks and districts. The resources shown reflect current designations as numerous historic resources are not yet designated and surveying and documentation continue. Additional information on the data used can be found at  http://nj.gov/dep/hpo/1identify/gis_LUCY_User_Guide_1.0.pdf .

Figure 1 and Table 1 show the historic properties and districts by type of resource in the state. New Jersey has 137,092 historic properties: National Historic Landmarks, listed, designated, eligible, or identified as historic. 544 of NJ’s 565 municipalities have at least one property. The state also has 1,596 districts: National Historic Landmarks, listed, designated, eligible, or identified as historic within every county and 512 municipalities.

Move the slider toward the right to view the historic properties and districts within the flood zones and toward the left to view the flood zones.

FEMA Flood Insurance Rate Maps (FIRMs) are commonly used to assess coastal and riverine flood hazard exposures in communities. Figure 2 above shows the areas from the FIRMs with a 1% or 0.2% annual chance of flooding. Individuals commonly refer to these areas as the 100-year (1%) and 500-year (0.2%) floodplain, respectively. The FEMA FIRMs do not include future projections of sea-level rise, precipitation, or coastal storms.

The area within the 100-year floodplain contains almost 16% of historic properties and 51% of historic districts in New Jersey. See Table 3 for the number of historic resources in the 100-year floodplain by their designation type. 1,494 of the at-risk historic properties are within a National Historic Landmark district, and one was evaluated individually as a National Historic Landmark. 5,317 historic properties are listed on the state or national registers, and 506 are locally designated. Eight are National Historic Landmarks, 229 are listed, and 24 are locally designated for the historic districts. As seen in Table 2, the area within the 500-year floodplain contains almost 22% of historic properties and over 54% of historic districts.

In addition to current FEMA Floodplain exposure, planners and decision-makers must identify assets that will become inundated by future flood events and sea-level rise (SLR) in coastal areas. The maps below further examine flood risk in NJ's 239 municipalities located along coastal and tidal water. We measure flood events using the height of the flood above Mean Higher High Water (MHHW). MHHW is the average height of the highest daily tide observed over the National Tidal Datum Epoch, a 19-year period. The analysis considers a property exposed to flooding when the modeled flood touches the center of the parcel. Districts are considered inundated when any part of the district is covered by a flood event. The color of each property or district represents the flood event that first touches the center of the parcel or part of the district. There are 84,486 historic properties and 749 historic districts within the coastal zone.

See Figure 3. Areas inundated during a 2-foot flood event experience nuisance flooding. Areas inundated by water during a 3-foot flood event may experience flooding during a Nor'Easter. Flooding will become more frequent in these areas as sea levels rise and the communities begin to experience more regular high tide flood events that are not associated with storms.

Source: NJSHPO and NJDEP

Zooming in on additional specific municipalities in the state shows how the statewide trends manifest at the local scale. Some communities face extreme risks because of their coastal location and low-lying communities, while others have minimal exposure due to their inland location and few waterways. The risk is varied. The maps and tables below examine six municipalities.

Source: NJSHPO, NJDEP, and FEMA

Hundreds of historic properties and districts in New Jersey are vulnerable to flood events due to either their location in a floodplain today or future increases in sea level. Almost 42% of historic districts and 22% of historic properties are in the 500-year floodplain. Over 20% of historic districts and 9% of historic properties in New Jersey are vulnerable to inundation during a 5-foot flood event. These properties include notable sites across the state like those already shown in the highlighted communities. Properties in the 500-year floodplain include dozens of historic homes and multiple houses of worship. Properties at risk of inundation during a 2-foot flood event include the Abel and Mary Nicholson House in Elsinboro. The landmarks Lucy the Elephant and the Atlantic City Convention Hall are vulnerable to inundation during a 5-foot flood event. These are only a few examples of the thousands of vulnerable resources bringing cultural value to their city and warranting protection.

This product was developed by the New Jersey Climate Change Resource Center Climate Resilience Corps. For more information about the Resource Center, visit:  https://njclimateresourcecenter.rutgers.edu/ 

This story map was developed using New Jersey Department of Environmental Protection Geographic Information System digital data, but this secondary product has not been verified by NJDEP and is not state-authorized or endorsed.