Tackling Urban Flooding by Restoring Our Canals

In November, an estimated 350,000 homes in England lost power as Storm Bert hit the nation (Source: Met Office). The UK suffered strong winds, snow and heavy rainfall which caused flooding throughout the country, damaging homes, businesses and roads and disrupting daily life. With more storms on the way, flooding will continue to affect many communities across the country. What can be done to tackle flooding in our urban areas? The answer may lie in embracing nature-based solutions such as canal restoration.

What causes flooding?

Rising global temperatures are key causes of flooding. As our oceans get warmer due to climate change, more water evaporates into the air. When this moisture-laden air joins a storm system and travels over land, we receive more intense rainfall which our urban areas struggle to handle.

For example, heavier rainfall in short time periods can overwhelm drainage systems, which can also become blocked by sediment and debris, leading to flooding. The disappearance of green spaces in urban areas due to building development also contributes to worsening flooding as water cannot drain to fields to be absorbed by soil and plants, instead it sits on the surface of concrete roads and pavements, closer to our homes.

Tackling Urban Flooding Through Canal Restoration

Digging a big hole in the ground is an excellent way to collect rainwater. Similarly, by restoring canal systems, particularly in low-lying areas, we can create more spaces to capture flood water that would otherwise damage homes, businesses and schools. Unlike ponds or lakes, canals have lock systems which let us control the flow of water, diverting it away from urban areas. By also channelling this canal water to other areas, in some cases, the water can be reintroduced into adjoining rivers to replace evaporated water during summer or in dry areas.

Despite being man-made waterways, canals provide thriving habitats for wildlife. Plant life in canals can absorb water through their root systems, helping to reduce the impacts of flooding and supporting a diverse, healthy ecosystem.

Other Benefits of Canals in Urban Areas

Canal restoration in towns and cities is particularly useful in tackling flooding, as canals can be connected to existing storm-water management systems or sewers to further reduce the risk of flooding. An additional benefit is that by using heat transfer technology, water from canals can be used to heat or cool nearby homes, at no risk to the environment. The Inland Waterways Association estimates that up to 350,000 homes could benefit on Canal & River Trust waterways alone, saving more than 1 million tonnes of CO2 each year.

Like flooding, heat-waves are also becoming more frequent in the UK and are made worse by the urban heat island effect which occurs in towns and cities. Concrete buildings and roads absorb heat and densely packed high-rise buildings reduce ventilation, trapping warm air between narrow streets. Introducing more waterways in urban areas can help reduce this effect because water naturally cools the air around it as it evaporates. According to the Canal and River Trust, waterways can cool temperatures in urban areas by up to 1.6 degrees, helping to reduce the harmful impacts of heat waves in urban areas.

Drawbacks

Since canals are man-made waterways, they require maintenance to operate efficiently. Sediment can build up over time, especially if dirty flood water drains into canals, meaning that they must be dredged and maintained to stop them overflowing. Also, flooding can occur if a canal falls into disrepair, for example its walls are broken or it fills up with rubbish. However, organisations like the Buckingham Canal Society are dedicated to maintaining the quality, safety and beauty of our canals, making them pleasant spaces to live and visit.

Protecting Nature and Our Communities

Flooding is a real threat to our communities. People have been injured or lost their lives in the recent storms, and many have been evacuated as their homes have been destroyed by flooding. While we cannot stop flooding through canal restoration alone, it goes to show that embracing nature-based solutions can significantly reduce the impacts of extreme weather. The effort to restore and protect natural habitats not only benefits nature, but has direct, tangible benefits for people too.

To be a part of the canal restoration work carried out by Buckingham Canal Society, visit our “get involved” page.

Photos by Chris Gallagher on Unsplash

Note: photos are from 2015 and not of flooding as a result of recent storms.