After the storm

The peak of hurricane season in the Atlantic Ocean has passed but the storms are not yet over. Hurricane Harvey broke rainfall records in the continental USA with its downpour severely impacting southeast Texas; Hurricane Irma, was one of the most powerful tropical cyclones ever recorded; and Hurricane Maria is likely to set a record for being the most rapidly intensifying hurricane ever measured. However, attributing climate change to hurricane patterns is not clear-cut. They are rare events with only a limited number of data points to identify a trend.

Although climate change cannot be pinpointed as the cause of a specific storm, a warmer climate is likely to result in more intense hurricanes and storms. This year, the North Atlantic has been warmer than average. This warm water helps storms intensify since the weather systems absorb heat energy from the water. It’s this energy that causes storms to get stronger much faster.

In addition to increasing ocean temperature, global warming is resulting in a sea level rise that increases vulnerability in densely populated urban areas to the storm surges that come with hurricanes. Climate change also brings a higher intensity of rainfall, with warmer temperatures increasing the capacity of the atmosphere to hold more moisture.

The intense rainfall seen in Austin, Texas, from Hurricane Harvey and in Puerto Rico from Hurricane Maria, can be devastating. The resulting flooding destroys infrastructure, disrupts services, including water supply, and results in fatalities.

When such devastating events happen, the emergency response and immediate recovery are the focus. After the storm has passed though, when the news agenda moves to the next crisis, the need to rebuild and assess how to better prepare and plan for the next event remains. Much like Hurricane Katrina and Sandy that devastated parts of the USA, the aftermath of the more recent Hurricane Harvey, Irma and now Maria, should trigger discussion and lead to important lessons around disaster preparation and response.

The IWA, through a portfolio of projects, including the GEF funded Flood and Drought Management Tools and European Commission (EC) financed Preparing for Extreme And Rare Events in coastaL Regions (PEARL) project, emphasise the importance of improving our planning capacities to ensure we are becoming more climate resilient.

The Flood and Drought Management Tools (FDMT) project is developing a package of web-based technical applications. These will improve the capacity of stakeholders operating in river basins to recognise and address the implications of their changing reality.

The applications, accessible on the Flood and Drought Portal, allow users to carry out baseline assessments using readily available satellite data, impact assessments through the analysis of the data, planning options for basins, water safety planning support for water utilities, identification of indicators for monitoring, and a means for disseminating information through reporting to relevant groups or individuals.

So how does this help prepare for the impacts of increasingly intense storms? Access to data and its analysis is an initial step in understanding the climate environment, and can help inform decisions on priorities for planning for extreme events.

PEARL also helps in preparing for extreme events. It aims to develop adaptive risk management strategies for coastal communities impacted by extreme hydro-meteorological events. The approach used takes into account not only scientific information but also social dimensions. Through the project, outputs such as flood risk maps and vulnerability maps have been developed for a number of case study areas.

Once you know the possible climate impacts, what kind of measures can you put in place? PEARL has developed a knowledge base to assess the vulnerability of a city to flooding, and then identifies engineering, environmental and operational measures for adaptation and mitigation.

While such applications and methods can provide part of the solution to improving capacity in a changing world, there also needs to be political will and the drive to accept and prepare for the storms ahead.



Floods and Droughts: risks, challenges and solutions in a climate changing environment

Organisers: Inter-American Development Bank (IDB) and International Water Association (IWA)
Location: Water and Development Congress, Buenos Aires, Argentina
Date and time: Tuesday, November 14th 15:30 – 17:00


How can we use available technologies to better prepare for flood and droughts?

As climate variability grows, uncertainty in water availability and quality also grows, and extreme events, such as flood and droughts, become more frequent, severe and less predictable. This workshop addresses the challenges posed by climate-related extreme events using technology to reduce impacts and improve planning. In the first half Katharine Cross, IWA, will highlight droughts, including how climate data and risk assessment can be used for drought preparedness . Following a discussion to share knowledge on drought issues, the focus turns to floods, with Mauro Nalesso, IDB, providing an overview of the challenges in the LAC region. This is followed by showcasing technology for flood forecasting and assessment from Reinaldo García, Hydronia and RTI. A second discussion will have an emphasis on floods and the use of technology to better prepare for these events.



The International Water Association (IWA) expresses its support to the families of all victims of these unfortunate meteorological events and associates its solidarity with all population affected. It is in times like this we look to the strength and courage of the people affected and the continued support from the international community. 

The Flood and Drought Management Tools (FDMT) project is funded in 2014 by the Global Environmental Facility (GEF), International Waters (IW) and implemented by the United Nations Environment Programme (UNEP) with DHI and the International Water Association (IWA) as executing agencies.

PEARL is funded by the European Commission through Horizon 2020. The project has a consortium of 24 partners and is led by UNESCO-IHE. IWA is leading on communication and dissemination.




Katharine Cross

Strategy and Partnerships Lead, Australian Water Partnership
Katharine has extensive experience in the water sector from global to local scale with a focus on climate resilience and adaptation, nature-based solutions, water-energy-food nexus,  water governance and the digitalisation of the water sector. She h... Read full biography