• Megan Parfitt

Flood risk in a time of water scarcity


You’d be forgiven for thinking that you are not at risk of flooding if you don’t live near a river, or you live on a hill. However, this is not the case.


Surface water flooding simply put is what happens when the soil is too hard to absorb water and when there is too much rain for drains; this, then, causes streets to fill with water. Surface water flooding doesn’t just impact homes, but businesses, transport and most aspects of modern life are disrupted [1].


How has climate change led to flooding?


Although it is hard to track how flooding patterns have developed in the past, it is clear that climate change has influenced water-related variables that contribute to flooding (e.g., rainfall, snowmelt).


We are all aware of the sea levels are rising. As ocean temperatures increase, glaciers and ice sheets melt which causes global sea levels to rise, putting many worldwide communities and great risk. In fact, research has predicted seas to rise between one and four feet by 2100 [2]. Have a look at the IPCC sea level projection tool to see how areas near you will be affected by sea level rise.


As the atmosphere is becoming warmer, it subsequently rains heavier. These more regular heavy precipitation events increase the potential for floods, particularly in urban areas where the concrete ground is impenetrable. Specifically, in the UK, summers are predicted to become drier whilst winters become wetter, along with increasingly extreme temperatures and rainfall events [3]. Although, this weather trend is likely to be experienced across the globe.


Many believe that because they live on a hill or nowhere near a river they are safe from flooding. Unfortunately, this is just not true. During prolonged downpours, sewers and drainage systems fill to the point of overload. This then spills out flooding the surrounding buildings and causing large amounts of damage. The belief of not being affected by flooding is exasperated by the fact that many places are currently experiencing water scarcity. However, water scarcity builds up over a long period of missing rainfall resulting in depleted reservoirs and groundwater levels. A few short periods of heavy rainfall are not enough to make up for the loss and most runs off soil without soaking in. This explains why it is possible to experience flooding at the same time as water scarcity.

How can we tackle flooding?

Climate Change


The IPCC has made clear that preventing global temperature rise to below 1.5 degrees is essential to limit the amount of future extreme weather. However, at the rate we are currently increasing, only ambitious climate action can now make that happen.


Preparation


Flood preparation can save properties, businesses and lives. Learn how you can receive information about local weather conditions (United States, United Kingdom). Furthermore, if you are at risk of flooding, consider investing in a flood insurance policy.


Have a plan for if there is local flood risk or flood alert. For example, know where you can get sandbags and have an emergency supply kit that includes food, bottled water, first-aid supplies, and a battery-operated radio. Avoid walking or driving through floodwaters. 12inches of water is enough to wash away a car and is also enough to hide hazards such as downed power lines and contaminants like sewage.


If you are told to evacuate, remember the “five Ps”: people, prescriptions, paper (birth certificates, passports etc), personal needs (clothes, phones etc), and priceless items). If there is time, move valuables to higher levels; turn off gas, water, and electricity; and place sandbags around your home [4].


Nature


Local councils can help protect communities against flooding by becoming more resilient to the effects of climate change. Nature-based solutions increase the variety of wildlife, and store carbon which helps tackle global warming and improve water quality.


Planting hedges and trees (which reduce surface water run-off), improving soil cover with plants (reduce water pollution and run-off) and restoring salt marshes, mudflats and peat bogs [5] all provide natural protection against flooding. Better yet, preserving the environmental features we already have will be the most effective way to protect communities from coastal erosion and flooding.


Individual action

There are various ways you can get involved with flood projects. For example, you can join a local flood action group or support projects by making contributions through partnership funding. It is also important to avoid flushing things down the toilet/sinks that can block local sewage and water systems (e.g., face wipes and sanitary items) and use sustainable drainage methods to avoid water runoff.


It isn’t possible to entirely eliminate flooding and it is difficult to predict where the heaviest rainfall will occur. However, we can take steps to reduce the impact on the community. Tackling climate change is the best chance we have at averting some of the worst-case scenarios regarding sea level rise and flood risk (have a look at other articles on our blog for ways to tackle climate change).

References

[1] Surface water: The biggest flood risk of all [Internet]. GOV.UK. 2018 [cited 2022Sep18]. Available from: https://www.gov.uk/government/news/surface-water-the-biggest-flood-risk-of-all

[2] Lin N, Kopp RE, Horton BP, Donnelly JP. Hurricane Sandy’s flood frequency increasing from year 1800 to 2100. Proceedings of the National Academy of Sciences. 2016;113(43):12071–5.

[3] Recent trends and future projections of UK storm activity [Internet]. Met Office. [cited 2022Sep18]. Available from: https://www.metoffice.gov.uk/research/news/2021/recent-trends-and-future-projections-of-uk-storm-activity

[4] 2019 [cited 2022Sep18]. Available from: https://www.nrdc.org/stories/flooding-and-climate-change-everything-you-need-know

[5] Use nature-based solutions to reduce flooding in your area [Internet]. GOV.UK. 2021 [cited 2022Sep18]. Available from: https://www.gov.uk/guidance/use-nature-based-solutions-to-reduce-flooding-in-your-area