On July 4, a horrific flash flood occurred in central Texas, mainly impacting Kerr County. The heavy rain started at about 3 a.m., resulting in rainwater surging down mountain slopes, causing the waters in the Guadalupe River to rise by eight metres very quickly.

At least 132 people have been confirmed dead as of July 14; most of them were in Kerr County. The area is under renewed flood warnings as heavy rains threaten to continue.

In recognition of the scope of this tragedy, it's important to determine why it happened. Texas Gov. Greg Abbott stated that a special session of the state legislature will be held in late July to investigate the emergency response.

Local Texas officials are facing questions over their actions in the hours - and years - before the flood. In recent years, multiple efforts in Kerr County to build a more substantial flood warning system have faltered or been abandoned due to budget concerns.

In 2015, a deadly Memorial Day flood in Kerr County rekindled debate over whether to install a flood monitoring system and sirens that would alert the public to evacuate when the river rose to dangerous levels. Some officials, cognizant of a 1987 flood that killed eight people on a church camp bus, thought it should be done, but the idea ran into opposition.

Some residents and elected officials opposed the installation of sirens, citing the cost and noise that they feared would result from repeated alarms. As a result, Kerr Country did not have emergency sirens that could have warned residents about the rising waters.

The critical challenge for communicating flash floods is ensuring that early warnings reach vulnerable populations. Unlike slow-onset river floods, flash floods leave very limited time for reaction. This makes accurate short-term forecasting and community preparedness essential.

The U.S. National Weather Service issued its first public warning about the flooding in Kerr County at 1:14 a.m. on July 4, warning of life-threatening flash flooding, with subsequent warnings triggering alerts.

Floodwaters surged dramatically as the Guadalupe River rose nearly eight metres in about 45 minutes. The 4:03 a.m. warning instructed residents to "Move to higher ground now! This is an extremely dangerous and life-threatening situation."

The warnings were disseminated at night through emergency management systems and television and radio stations, but many people, including hundreds of children at summer camps, did not receive them.

Government agencies at all levels need to work together to ensure that residents of impacted areas move effectively to outside of the flood area or at least to higher elevation areas or safe buildings.

The World Economic Forum's Global Risk Assessment for 10-year periods ranked extreme weather events as the highest global risk in both the 2024 and 2025 assessments. Floods are a very important extreme weather event.

The U.S. National Centers for Environmental Information published its review of events for the period 1980-2024. Tropical cyclones were the costliest weather and climate disasters, followed by: droughts, wildfires and flooding, which had an average cost of US$4.5 billion per event. The number of billion-dollar inland flood events has increased in the U.S.

Note that the dollar costs of these events in these assessments do not include the many societal impacts, including mental trauma and other health impacts.

There have been major reductions in the staffing and budgetary support of the U.S. National Oceanic and Atmospheric Administration (NOAA) and the National Weather Services, which is part of NOAA.

Read more: Terminations at U.S. government agencies that monitor extreme weather events will have negative effects

The impacts of these reductions on the weather and flood forecasts that would have alerted Texans on July 4 are not yet clear. At the time of writing, the website for the National Weather Services office for Austin/San Antonio, which covers the region that includes hard-hit Kerr County, shows six of 27 positions are listed as vacant. One important vacancy is that of the key manager responsible for issuing warnings and co-ordinating with local emergency management officials.

The U.S. government has also reduced the funding for research on weather systems, including floods. There have also been reductions in the funding support for scientific analyses of how climate change will affect the severity of storms.

Deep funding cuts to NOAA may result in the termination of both the National Severe Storms Lab and the Cooperative Institute for Severe and High-Impact Weather Research and Operations at the University of Oklahoma, which will have a highly negative impact on the understanding of storms.

Read more: Trump's budget cuts are adding to risk in life-threatening floods and emergencies

The Canadian Severe Storms Laboratory was established in 2024 at Western University to conduct leading research on severe weather in Canada.

Flooding is the most common and costly disaster in Canada. In the past decade, floods have averaged nearly $800 million in insured losses annually.

Over time, the potential for extreme rainfall events is increasing. Heavy rainfall events and their ensuing flood risks are increasing because of warmer temperatures.

Canadian data shows that climate change is driving increasingly severe and frequent floods.

Flooding will only get worse in the future, and government action is needed to manage this growing risk. One of the ways in which Canada isn't prepared is that most flood-risk maps are out of date, with some being decades old.

While Environment and Climate Change Canada issues weather watches and warnings for things like tornadoes, severe thunderstorms and rainfall, it doesn't provide flood forecasts.

Most provinces argue that water resources are natural resources and are therefore under provincial jurisdiction. This means that weather forecasts across the country are provided by the Meteorological Service of Canada, while flood forecasts are produced by each of the provinces.

It is important to take actions to address adaptation and climate resilience that consider future floods and their impacts. Federal, provincial and territorial governments will need to work together to avoid tragedies.