After a glorious summer and mild autumn, 2014 made it’s entry with high winds, storm surges and widespread flooding across Wales. This wet weather has not only caused difficulty and frustration for people, but also has the potential to spell disaster for wildlife, especially those creatures that make their homes in and around our waterways.
The flooding of homes is a problem for wildlife too, with bankside Otter holts and Water Vole burrows now under water. Deep, fast flowing rivers and streams make hunting difficult for piscivores such as Herons and Kingfishers, and the eggs of migratory fish laid in spawning grounds earlier in the season are at risk of being washed away.
But there is a more insidious danger facing water dwelling wildlife during periods of high rainfall and flood. Urban diffuse pollution is a problem for many of Wales’s waterways, and has the potential to impact many different types of wildlife. This threat is directly linked to human activity in and around the home, yet the vast majority of homeowners are completely unaware that what they put down their toilets and sinks or use in their garden has the potential to end up in their local river or stream, eventually making its way to the sea.
The majority of Wales is served by what is known as a combined sewer system, in which both foul water from our sinks and toilets, and storm water runoff is carried in the same piping. These systems worked very well when they were first built in the Victorian era, however modern pressures such as population growth, reduction in green spaces for absorption and also climate change means that these systems can often become overwhelmed during periods of high usage, such as during periods of heavy rainfall.
To cope with this, and prevent the sewer from becoming overloaded and backing up through our drains, the system empties itself into the local river or stream when it reaches capacity through a devise known as a Combined Sewer Overflow, or CSO. This means that everything that has been tipped down the drain or has run-off our garden ends up in the local waterways, and it will come as no surprise that household chemicals such as bleach, detergent, cooking oil and garden fertilisers are not welcome additions to aquatic habitats, and can cause nutrient overloading, water de –oxygenation and in extreme cases, poisoning of local wildlife.
Happily, there are precautions that we as homeowners can take to minimise our impact on local waterways. Being mindful not only of of what we tip and throw down our drains and use on our gardens but also of how much water we use around the home can all go a long way to tackle urban diffuse pollution. Try changing your habits by using an eco-friendly cleaning detergent, taking shorter showers or going organic in the garden!
Our waterways, both fresh and saltwater provide habitat for a wonderful variety of wildlife. This year, WTSWW are running a series of watery wildlife themed walks and talks to get people out and about across Swansea County, ranging from bat walks to otter surveys. To find out more, visit our website www.welshwildlife.org/events, or email Rhi.