In South Florida cities like Fort Lauderdale, critical affordable housing units are threatened by sea level rise

“Every affordable unit that exists is a precious asset for our country,” says Laurie Schoeman, national director of resilience and disaster recovery for Enterprise Community Partners, a national nonprofit affordable housing developer. “It’s so hard to replenish housing stock once it’s lost, often due to NIMBYism and racism. Both lead to lost affordable housing stock not being replaced anytime soon.”

The specter of flooding hints at the cascading series of climate vulnerabilities slowly inundating lower-income Americans who depend on affordable, and often aged, housing. Older homes tend to be poorer quality, suffer from deferred maintenance, and are more physically vulnerable to flooding damage (not to mention rising heat), all while housing a disproportionate amount of disabled, elderly and otherwise at-risk residents.

The problem is intertwined with housing discrimination: Many flood-threatened properties also reside in areas that suffered from historic “redlining” practices that discriminated against Black homebuyers; these neighborhoods already bear an increased pollution burden and tend to be more vulnerable to extreme heat. Frequent flooding will likely result in disrupted electrical equipment, contaminated water sources and septic systems, mold formation, and damaged roads, exacerbating the $70 billion national maintenance backlog that already afflicts U.S. public housing.

Todd Nedwick of the National Housing Trust says there’s little funding for affordable housing to begin with, and cities are just starting to support risk assessments for future flooding damage (Washington, D.C., just updated its flood hazard rules this April). Losing any units amid a nationwide affordability crisis, where there’s just 35 units available for every 100 extremely low-income renters, only adds to what the National Low Income Housing Coalition says is a national shortfall of over 7 million units.

“The point here is that two neighbors can suffer from the same flood, one living in affordable housing and one in a home they own, and experience a very different outcome,” says Benjamin Strauss, a co-author of the report and CEO and chief scientist at Climate Central. “Many more people in the general population will be affected by sea level rise than the affordable housing population. But the affordable population group is the one likely to hurt the most, who can’t afford to find a remedy on their own, and tend to not have the voice needed to change the allocation of public resources.”

The analysis undergirding the report, which looks at both expected annual flood-risk events and expected annual exposure, is far more precise than previous efforts, and was made possible by recent advances in data collection. Microsoft recently curated a collection of the building footprints of every single structure in the lower 48 states, while the National Housing Preservation Database plotted every subsidized and naturally occurring affordable housing units in the country. The research and accompanying online mapping tool shows building-by-building impact. Previous analyses looked at census block-or-larger parcels and applied flooding risk equally across the area “like a thin layer of peanut butter,” according to Strauss.

This new, more detailed analysis reveals some potential good news, too. The threat is concentrated in a relatively small area, says Strauss, suggesting targeted intervention could protect a lot of at-risk housing. Remediation of housing and relocation of tenants are both expensive and challenging, so being able to pinpoint affected units and buildings makes it easier to stretch limited funding. Strauss and his co-authors hope this analysis can provide the information needed to fix the problem, and hopes to complete cost analyses in the future to underline the price of doing nothing.

A handful of existing programs have tried to boost the climate resilience of affordable housing. Boston, where 3,042 units could be lost to flooding, has a program to help owners assess the flood risks of their property. Miami mapped the vulnerability of its affordable housing stock a few years ago, especially multifamily buildings, and will soon launch a program in partnership with Enterprise Community Partners called Keep Safe Miami, which will provide funding so 50 owners of affordable housing can fortify their properties from flood and hurricane damage (it’s based on a similar program launched in Puerto Rico after Hurricane Maria). Miami is fronting half a million dollars for the program.

Schoeman says more funding and city-led programs that help fund mitigation, and not just repair damage after the fact, are needed. Keep Safe highlights an issue that makes affordable housing, especially older multifamily units, so vulnerable to climate change: decades of deferred maintenance. She points to Los Angeles’s program to retrofit older buildings to withstand earthquakes, the seismic retrofit ordinance, as an example of how to support change, update older buildings and push the market to embrace resilience.

Will the incoming Biden administration take this issue more seriously? Priya Jayachandran, president of the National Housing Trust, hopes the naming of a climate czar and the HUD transition team’s interest in energy efficiency and resiliency issues suggests more resources will be made available to tackle the issue, such as tapping community development block grant funding. It’s also one of her organization’s priorities to get the housing dimension of climate change in front of legislators and policymakers now, and start working on ways to preserve these units. It’s easy to imagine a climate-challenged future where residents of affordable housing are simply given vouchers and asked to move elsewhere.

“There are people who would say any buildings in the floodplain shouldn’t exist,” says Jayachandran. “It’s not necessarily fair to pit the climate and housing crisis against each other. The housing crisis is severe. We need to both save existing stock and make it more resilient.”