The problem with this approach is that it ignores longer-term issues that are potentially far more serious and far more expensive to address. Cities and counties have always assumed responsibility for protecting their citizens from a certain range of hazards and for proactively enhancing their quality of life by providing basic services that make urban living convenient and productive. Police Departments protect against criminals, Fire Departments respond when a structure catches fire, and utility departments (or private utility companies) provide water service, sanitary sewer service, electrical service and a variety of similar services that almost all of us have come to depend upon. Cities have also acted in response to occasional natural disasters (e.g. floods or tornadoes) with recovery services to help people get back on their feet when nature acts unpredictably. Both our society and our economy would be much worse off were it not for these cooperatively run services provided or organized through government action.
Increasingly, however, municipal officials and many citizens are worried that the landscape has fundamentally shifted to include life-safety issues that are, if not completely new, at least significantly different in scale, frequency and character. The recent wildfires in Los Angeles and the torrential rains and resulting flooding in Asheville, North Carolina, are two examples of the kinds of life-safety issues that I have in mind. I cannot categorically say that either event was caused by climate change or was even made worse by climate change. Wildfires and floods have been happening for a long time and there are always multiple contributing factors. But it is a reasonable assumption that climate change played some role and it is a connection that gets a lot of play in the popular press. More to the point, it may not matter whether climate change was involved or not. It is human nature to want an explanation for why bad things happen, and regardless of why these events happened, we as a society seem to believe that local government should help protect us.
Hence, part two of the conundrum: What should cities (and counties) do, if anything, before disaster strikes again? The flooding in the Asheville area, for example, was the result of Hurricane Helene moving inland with huge amounts of moisture that eventually fell in western North Carolina. Climate scientists have been warning that warmer oceans were likely to super-charge hurricanes, and various weather stations in the Asheville area reported unprecedented amounts of rain during the three day storm (14 to 23 inches). Should local officials have anticipated that this might happen and have taken steps to minimize damage or speed recovery efforts? Such steps, particularly if they were viewed as “extreme” compared with prior flood protection actions, would probably have been met with derision and concerns about wasted taxpayer dollars for such an unlikely event. Yet in hindsight, additional preventative actions might have saved lives and millions of dollars in property damage.
Unfortunately, hindsight tends to warp our perspective on what is reasonable. Actions that appear logical in hindsight might well have appeared wasteful or borderline crazy before the natural disaster occurred. Climate change, however, may have altered the nature of the game. If, in fact, citizens perceive that climate change is making disasters more frequent as climate scientists are predicting, then the range of preventative actions that city officials should consider will need to expand to include things that might have been rejected as government overreach just 20 or 30 years ago. No mayor or city manager wants to be at the front of a post-disaster press conference being asked “Why didn’t you do more to prevent this destruction?” This is an especially hard question to answer when climate activists have been ringing the alarm bells for years.
This post is not about preventing global warming or debating the merits of climate science. All of that is irrelevant because the earth has already warmed to 1.5 degrees C above the pre-industrial baseline and reaching 2 degrees C in the near future seems almost inevitable. This post will be about adapting to a warming planet regardless of why that warming is taking place. The narrative – already firmly entrenched in the public mind – can be summarized as follows:
The data shows the earth is warming to worrisome levels;
Climate scientists warn that global warming can make bad things happen; and
Bad things are happening.
It makes no difference whether climate change caused a particular disaster to happen or not, because government officials are going to be held accountable if there is a perception that they did not take “reasonable” steps to prevent or respond to the disaster. Unfortunately, they will also be held accountable if they take expensive actions to mitigate a disaster that never occurs. Navigating this minefield will be tricky.
The Basics of Climate Adaptation
Cities obviously change over time, but they don’t change their form quickly or easily. Much of the physical form of a city is literally poured in concrete and is designed to last for decades. Yes, anything that is built can be torn down, redesigned and rebuilt, but that is expensive and disruptive. If climate change is really tilting the playing field in a way that is so fundamental that it will affect city form, then cities need to start planning for how best to adapt to that new playing field as soon as possible. The cruel reality is that cities need to start the adaptation process before they know exactly the nature and extent of the changes that will be taking place.
Consequently, I am going to focus on the basics – the two climate impacts that seem most likely to happen and the three secondary effects that are potentially the most serious. Given my geographic emphasis on the midwest, I am going to ignore sea level rise and warming oceans even though those issues are crucial for coastal areas. I’m also going to ignore (at least for now) one of the most obvious ripple effects from global warming which is the negative health impacts from extreme heat days. Extreme heat is a clear problem, but I think the actions in response to that problem are likely to be easier to implement quickly than the topics I want to address in this post.
The first predicted climate impact is that droughts will be more frequent and longer in duration than what we are used to experiencing. A warmer atmosphere increases evaporation from both the soil and plants which then leads to drought conditions that can affect water supplies, agricultural production, and wildfire potential. Much of the midwest is already considered “abnormally dry” or in a “moderate drought” and continued climate change is likely to make that worse.
The second predicted impact is that rain storms will get more torrential in nature – in other words, heavier rains in shorter periods of time. These torrential storms may not be very frequent, but when they happen they will cause significant flooding to structures that are out of the traditional floodplain and damage to infrastructure that was thought to be safe from flood waters.
At first glance, it might seem that these two climate impacts would cancel each other out – several months of drought followed by a heavy rain that restores the normal balance. In practice, however, it rarely works out so neatly. A drought, for example, might last for years and create a moisture deficit that a single storm cannot overcome. In addition, a drought tends to bake the soil which makes it less able to absorb moisture when it eventually rains. The water from a heavy storm simply runs off and increases potential flooding rather than soaking into the ground where it is really needed. Even under non-drought circumstances, a really heavy rain saturates the top inch or two of soil very quickly and then the volume of water tends to overwhelm the soil’s absorptive capabilities and everything that follows becomes runoff anyway. A series of smaller storms or a long, drawn out storm where rain falls at a slower rate is much better for recharging ground water levels.
On the surface, neither of these projected climate impacts seem all that terrible. The midwest (and most of the world) has experienced droughts and heavy rains before and survived just fine. But what if climate change turns what used to be rare events into commonplace ones? That possibility might trigger changes to the way we build and operate cities, and it is that scenario that I will examine for the rest of this post.
Beware the WUI
Everyone likes a house with a view of nature. Perhaps a home in a low-density neighborhood in the green foothills overlooking the urban core. Or maybe a home in a wooded subdivision where deer enter your yard to nibble at your flowers. Close enough to the city to take advantage of all it has to offer, but far enough away that you feel like you live in the country. Welcome to the Wildland Urban Interface (WUI). This is the fringe area surrounding many cities where urban development is intermixed with a substantial amount of nature.
Not every city has a WUI, but most do and in some cases they are quite large in area. In fact, roughly 44 million homes are in the WUI nationwide (roughly a third of all housing units), up from 30 million units in 1990. During that same period of time, the estimated area of the WUI increased by nearly 70,000 square miles – an area roughly the size of the State of Washington. [1]
Why is this trend important? Because an expanding WUI combined with increasing drought levels has substantially reshaped urban fire risks. Traditionally, fire departments were primarily concerned with how fast they could respond to a house fire or how effectively they could fight a fire in a high-rise building. Now, fighting wildfires in suburban fringe locations is rapidly growing in importance. The recent Los Angeles wildfires are a particularly horrific case in point, but each year there are dozens of smaller WUI fires that are largely limited in scope but which have the potential to be much worse if conditions change.
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| Source: National Interagency Fire Center |
Wildfires in general are much more common than most people realize. On any given day, there are typically hundreds of wildfires scattered across the country. Thankfully, the vast majority are relatively small, easily contained, and do little damage to occupied structures. The threat is growing, however, as evidenced by the accompanying chart. While the number of wildfires has not grown substantially, the number of acres burned by wildfires has roughly tripled in the past 40 years. South Carolina recently reported 175 fires burning across the state, forcing multiple evacuation orders and straining fire response resources. The largest was in Carolina Forest, a community west of Myrtle Beach. At one point, the fire grew to more than 1,600 acres and forced residents of half a dozen neighborhoods to evacuate. [2]
There is a perception that wildfires are just a California problem, but as the South Carolina example illustrates, that is not the case. Dozens of states have areas where the risk of wildfires is high and if drought conditions continue to spread that list will grow. The problem from a local government standpoint is that fighting a WUI wildfire is extremely difficult and many communities are unprepared. Unlike wildfires in remote locations, it is politically impossible in urbanized areas to define a defensible boundary and let the fire burn out within that area. In the WUI, firefighters feel obligated to try to save each residence even when high winds and rapidly spreading fires make that a dangerous and often futile approach. The difficulty of fighting a WUI wildfire is exacerbated by the need to notify and evacuate potentially hundreds or thousands of residents. WUI areas are often full of long, dead-end streets or neighborhoods with just a couple of exits and the logistics of getting people to safety can be daunting.
Residents of WUI neighborhoods often have a false sense of security because they have municipal water systems with regularly spaced fire hydrants. As the LA wildfires pointed out, however, municipal water lines are not designed to fight wildfires across hundreds of acres. Just a month prior to the LA fires, the Wall Street Journal published an article touting private fire hydrants as the latest trendy accessory for homes in fire prone areas. [3] Most of the examples cited had private water tanks for supplying the hydrants or were able to pump out of swimming pools. The fact of the matter is, however, that a WUI wildfire fueled by high winds is likely to spread so fast and be so intense that neither public or private hydrants are likely to make much difference. Just four years ago, the Marshall fire east of Boulder, Colorado, destroyed over 1,000 homes in just a few hours despite the fire hydrants located throughout the community.
At a minimum, cities with WUI neighborhoods need to have a specific strategy for wildfire detection, resident evacuation, and firefighter response. This is true even in cities that have not historically had wildfire problems. When it comes to wildfires, an ounce of prevention is worth several pounds of cure. Specialized equipment and supplementary water sources are desirable if budgets allow. In particular, new types of remote sensors backed by artificial intelligence can dramatically improve the odds of early detection which can trigger a response before fires get out of control.
The ultimate strategy would be to enact limits on WUI development or to require special construction and site design elements to reduce fire damage. In a sense, property owners in the WUI are creating their own problem by building in an area with elevated fire risk and by creating so much value in natural areas that firefighting strategies are forced to change. Controlled burns that preemptively reduce wildfire risk are nearly impossible where million dollar homes are scattered throughout the area. Requiring property owners to spend money or prohibiting development in scenic areas, however, is a politically difficult concept to sell.
Rain Rain Go Away
The seemingly opposite problems caused by too much rain are equally challenging to address. Most urban residents are familiar with the flooding of property near rivers and creeks when a heavy rain forces those bodies of water outside their normal channels. The problem is that climate change could force cities to deal with flooding on an entirely different scale and in locations that were previously thought to be safe from flooding. Where wildfires create largely operational problems for cities, flooding creates largely physical problems.
To appreciate the nature of the challenge, it is helpful to understand how civil engineers have historically dealt with stormwater runoff. In a normal rain, the water that isn’t absorbed into the soil runs to the gutters along most streets, is collected by stormwater inlets which route the water into underground storm sewer pipes, which eventually empty into larger drainage channels or streams. This all works pretty reliably in most situations, but it is an expensive system to build for cities and developers. Consequently, the underground stormwater system is typically designed to handle storms that are relatively common – for example, a storm that might happen every five to ten years on average.
Should a larger storm occur, the underground system gets overloaded and the surplus water flows downhill toward the nearest creek over the surface of the ground. This “overland flow” takes place mainly in streets and in swales (shallow channels) in between buildings. This secondary system generally works well, although nuisance-level flooding (e.g. wet basements) can be common. In addition, the larger drainage channels, creeks and rivers can get overloaded to the point where they overflow their banks into what is known as the floodplain. Most cities try to keep floodplain areas free from substantial structures so that occasional flooding does not do much damage. Natural areas, ballfields, pedestrian trails, and parks are commonly located in floodplains for this very reason.
What happens if a really big storm takes place? Then the whole system gets overwhelmed and serious flood damage is widespread. Even structures near the top of the hill can get flooded because the stormwater can’t find a way to the creeks and rivers fast enough. City officials count on really big storms being rare enough that they can be absolved of responsibility because “no one could have predicted” such a terrible event. Such events can, of course, be predicted but if they are rare enough then politicians are typically given a pass. A once-in-a-lifetime event is not something that gets a mayor or council person voted out of office. Climate change, however, might be escalating that once-in-a-lifetime event into something that happens every 20 or 30 years. Ignoring catastrophic events that used to be rare but now are common can get you voted out of office, which means there are a lot of politicians praying that climate change isn’t real because taking effective action is too expensive to contemplate.
The core problem that underlies all of this engineering design work is a table of rainfall probabilities called the Precipitation-Frequency Atlas of the United States. The current version is known as Atlas 14. This atlas contains estimates for hundreds of locations across the country of how much rain will fall in a storm with a particular frequency – a 20 percent chance of happening each year (a 5-year storm), a five percent chance of happening (a 20-year storm), a 2 percent chance (a 50-year storm), a 1 percent chance (a 100-year storm), and so on and so on. This data is used by engineers to calculate how big a storm sewer pipe needs to be to accommodate a 10-year storm, or how much clearance a bridge needs to allow a 50-year storm to pass without damage, or where the boundary line of the 100-year floodplain should be. In short, this atlas of rainfall probabilities is foundational to the engineering design decisions behind most of what is built in urban environments. And, unfortunately, it is fatally flawed. [4]
The rainfall estimates in Atlas 14 are based upon actual rainfall records going back at least decades, and in some places, hundreds of years. The problem is that each data point is equally weighted in the probability calculations as if rainfall patterns were unchanging. Unfortunately, rainfall patterns are changing and this reality will be incorporated in the next Atlas version, but that is not scheduled to be released until 2027. Earlier in this post I noted that Asheville, North Carolina, received over 14 inches of rain during their three-day storm. The Atlas 14 precipitation estimate for a three-day event in Asheville is 6.56 inches for a 100-year storm and 7.89 inches for a 500-year storm. What actually occurred as a result of Hurricane Helene was literally off the charts. The bottom line is that cities are facing a double whammy when it comes to stormwater. First, heavy rain events are forecast to be significantly more likely than in the past, and second, much of the public infrastructure that cities rely upon is under-designed to a significant degree.
There is no way that cities can afford to redesign and replace existing storm sewer systems to accommodate larger storms. Cities can, however, identify areas where higher flood risks due to climate change are likely to be most problematic. In fact, private companies such as the First Street Foundation are already providing such risk assessments. My opinion is that local government should take the lead in providing that information because they have the most knowledge of local circumstances and development trends. Regardless of who provides the data, property owners need to know that past flooding trends are no longer representative of future events so that they can take steps to prevent flood damage.
Many cities already have an inventory of known stormwater problems and their response has typically been to require new, upstream development to install what is known as on-site stormwater detention basins. These are holding areas designed to temporarily keep stormwater on site during a heavy rain so that downstream pipes and creeks are not overwhelmed. This approach works but in my opinion it is a long-term maintenance nightmare. Private property owners do not have much incentive to spend maintenance dollars on a system that doesn’t benefit them directly. Cities can mandate maintenance and do periodic inspections, but those programs are often underfunded and only half-heartedly enforced.
Instead of dozens of small, privately owned detention facilities, cities would be better off with larger facilities owned and maintained by the local government. Cities will need to be opportunistic and aggressive in finding places to install large-scale detention but I think it will be the best long-term approach. Many parks and public facilities with open land are already used for this purpose or for other stormwater mitigation actions, but most cities will need to do more than they have done in the past. For example, cities need to get serious about buying properties that flood repeatedly and turning those properties into detention basins. FEMA can supply grants to assist with this process through their Hazard Mitigation program (assuming that funding is not cut by the new administration). This is not, however, a quick-fix solution. It is a long-term grind that will pay benefits eventually but which will be messy and controversial in the near term.
The Things We Take For Granted
The direct damage caused by wildfires, floods or other natural disasters is bad enough, but there are secondary impacts that don’t get as much play in the press despite the problems they cause. These impacts include long-term environmental damage and the destruction of infrastructure systems that are essential for urban life. The Los Angeles wildfires, for example, left behind ash and debris loaded with toxic chemicals such as lead, asbestos, PFAS, pesticides, battery acids and more. Although clean-up efforts are well underway, no one really knows how effective those efforts will be and what long-term effects might linger in the area. It is possible that normal activities like outdoor exercise, or planting a garden, or playing in the park will become sources of health risk that we typically don’t associate with climate change.
In addition, natural disasters often damage or destroy water systems, sewage treatment systems, electrical grids, bridges, roadways, transit systems and other critical infrastructure components we depend on for normal day-to-day life. In previous posts, I have written about the fragility of many infrastructure systems due largely to poor maintenance procedures, but that fragility is particularly apparent during a disaster. It can take weeks, months or even years to restore service to previous levels and there is not a single city that is immune to this type of disruption. The fact of the matter is that we design infrastructure systems to handle normal loads during a normal range of events and normal weather fluctuations. Building systems that are hardened against torrential rains, tornadoes, hurricanes, wildfires or other climate disasters is simply more costly than we can afford.
Consequently, the focus tends to shift to resiliency – or the ability to bounce back after a disaster has occurred. Here there are substantial differences between cities and utility providers because some are prepared for things to go wrong while others are not. In this post, I am going to focus on water systems as an example of what can go wrong in response to climate change, but every infrastructure category has a similar set of risks. I have chosen water systems because I think they are particularly vulnerable to climate related disasters and because living in a city without water service for more than a brief time has major health and economic consequences. In a nutshell, here is what can go wrong:
Water quantity issues. The source of water for the vast majority of public systems is either a local reservoir, nearby rivers, or wells that tap into underground aquifers. All of these sources are subject to serious curtailment during an extended drought. The possibility of a city running out of water is known as a “Day Zero” event and the odds of it happening are higher than most people realize. Cape Town and Mexico City are particularly at risk and only extreme conservation requirements have kept them from a Day Zero disaster. [5] No U.S. cities are in imminent danger of running out of water, but in the future it is not an inconceivable outcome. The Colorado River basin, for example, provides water to 40 million people in cities like Los Angeles and Phoenix and continued drought endangers that supply. Many cities in the western Great Plains draw their water from the Ogallala Aquifer which is being drained much faster than it can be recharged. Irreversible shortages are still decades away but the warning signs are clear.
Cities need to diversify and protect their water supply sources, or at least have contingency plans in place to do so. There are engineering solutions available in most locations – new reservoirs, pipelines from other watersheds, or water desalination plants – but they are expensive to build and take years to bring online. Access to plentiful, clean water may eventually be more valuable than gold mines or oil fields.
Water quality issues. While running out of water is certainly scary, water source contamination is a much larger potential problem. Natural disasters exacerbated by climate change have the potential to destroy access to potable water by introducing pollutants that are not easily filtered out using typical water purification techniques. Wildfires, for example, can leave behind ash and other particulates that can flow into downstream rivers and reservoirs in large enough quantities to create major alkalinity and turbidity problems for water treatment plants. The Hermits Peak-Calf Canyon fire in New Mexico, for example, caused the Gallinas River to run black for a period of time and dumped so much toxic debris into the reservoirs for the city of Las Vegas, New Mexico, that the city’s water treatment plant failed. [6]
The City of Miami is seemingly surrounded by water but fears are mounting that contamination of the Biscayne Aquifer could render much of that water unusable. Saltwater intrusion caused by sea level rise and high rates of water extraction, combined with pollution from septic tanks and industrial properties, could significantly curtail the amount of fresh water available to the 6 million residents in the Miami metro area.
Infrastructure damage. The torrential rains in Asheville, North Carolina, not only deposited tons of silt into the city’s reservoirs, but also damaged all three water treatment plants and destroyed several supply lines from the treatment plants into the city’s distribution system. It took roughly three weeks for non-potable water to be available throughout most of the city [6] and 53 days before potable water service was restored. After a disaster, the headlines tend to focus on the number of residences or major commercial structures destroyed, but infrastructure damage hurts even the structures that were spared direct damage.
As noted earlier, it would be incredibly expensive to build urban infrastructure that was impervious to natural disasters. However, it is possible to identify the crucial pieces that are essential to recovery and make those as hardened against disaster as possible. Resiliency is mostly about planning and preparing for the unexpected.
The Bottom Line
There is no easy answer to the climate change conundrum. How much money should cities spend to prepare for a deluge, firestorm or drought that might never come? This is a particularly vexing question given the current political environment in which even innocuous mentions of climate change are being scrubbed from federal websites. It is almost as if climate change has become the political equivalent of Lord Voldemort – an evil too terrifying to even say out loud.
In an effort to gain some objectivity, I have been paying close attention to the current chaos in the property insurance industry. If anyone should know about risk it should be insurance companies and their recent actions seem ominous indeed. Companies are dropping long-time clients in risky areas even if they have never filed a claim. State funded insurers-of-last-resort have more clients than they ever thought they would and arguably more than is financially prudent. Insurance companies are raising rates as fast as state regulators will allow and yet financial returns for property and casualty lines (particularly homeowners insurance) are generally below expected norms. Insurance companies aren’t debating climate science, they appear to be girding for Armageddon.
My focus is not so much on the current state of the world as it is on the trend line. In my opinion, things are trending in the wrong direction. If I had to err on one side or the other, I would err on the side of doing too much to prepare for a new normal rather than doing too little in hopes that the old normal returns. I have, of course, been known to be wrong, but that is where I currently stand and if anyone is listening that is the advice I would give.
Notes:
1. “Where Humans and Forests Meet: The Rapidly Growing Wildland-Urban Interface”; U.S. Forest Service (Department of Agriculture); April 2024; https://research.fs.usda.gov/nrs/products/rooted-research/where-humans-and-forests-meet-rapidly-growing-wildland-urban-interface#:~:text=Between%201990%20and%202020%2C%20the,30%20million%20to%2044%20million.
2. Christopher Cann and Thao Nguyen; “Wildfires rage across the Carolinas; South Carolina governor issues State of Emergency”; March 2025; USAToday; https://www.usatoday.com/story/news/nation/2025/03/02/wildfires-south-carolina-myrtle-beach-north-carolina/81062101007/
3. Nancy Keates; “Hot Home Feature: A Fire Hydrant”; December 6, 2024; The Wall Street Journal
4. Thomas Frank; “We’re Building Things Based on a Climate We No Longer Live In”; June 2023; Scientific American; https://www.scientificamerican.com/article/were-building-things-based-on-a-climate-we-no-longer-live-in/
5. “2 Billion People Are at Risk of a ‘Day Zero’ Crisis – Here’s How We Can Avoid It”; March 2024; XPrize; https://www.xprize.org/prizes/water/articles/water-scarcity-day-zero-crisis
Patrick Lohmann; “Las Vegas to get $98 million to replace water treatment facilities after 2022 wildfire damage”; August 2024; SourceNM; https://sourcenm.com/briefs/las-vegas-n-m-to-get-98-million-to-replace-water-treatment-facilities-after-2022-wildfire-damage/#:~:text=by%20Patrick%20Lohmann%2C%20Source%20New,that%20polluted%20the%20city's%20reservoirs.
6. Sarah Honosky; “Non-potable water returns to nearly 95% of Asheville’s system”; October, 2024; Asheville Citizen Times; https://www.citizen-times.com/story/news/local/2024/10/21/non-potable-water-service-returns-to-nearly-95-of-ashevilles-system/75722093007/
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