Freshwater in the UK: ex-stream-ly polluted?
A riverlation about causes, effects and solutions
The current state of our rivers: All of them fail chemical standards. Only 14% of rivers pass the bar for good ecological health.
Do you remember this?
If you were in the UK mid/end October 2023, you may have witnessed the implications of storm Babet, which derived from Dublin after heavy rainfalls. Present from the 18th to 20th of October, the storm resulted in the most severe disruptive weather of the year 2023 in the UK. Despite evacuation plans, seven people lost their life and power cuts, rail service disruptions, flooded homes and crop losses occurred.
The whole climate is changing: the winds, the ocean currents, the storm patterns, [...] flooding, droughts. - John Holdren, American physicist
Picture: SkyNews
Intense storms and heavy rainfall can lead to increased soil runoff and floods, spreading pollution into our rivers.
Those are only a few of the reasons why our rivers are polluted - what are other causes?
Why is pollution problematic?
To see the effects of pollution, a study on macroinvertebrate biodiversity has been conducted. Two brooks from the West Midlands were sampled. Hilton Brook, which runs through a rural area, compared to Smestow Brook, running through an urbanised area. Samples were collected via the method kick sampling.
The results were that the biodiversity of macroinvertebrates highly varied depending on the brook. Conclusions about the water quality can be drawn, determined by the existence of indicator species. Examples for pollution sensitive species are Mayfly and Stonefly larvae, whereas waterlouse or freshwater shrimp are less sensitive.
Left to right: Mayfly larvae, Stonefly larvae, Freshwater shrimp
Infographic on how to assess water quality using macroinvertebrate communities
Left: Hilton Brook, right: Smestow Brook
Hilton Brook
Eight different invertebrate families were identified. There is plenty of biodiversity, with sensitive families such as Stonefly and Mayfly larvae.
As a result, the water quality of Hilton Brook can be described as excellent.
Smestow Brook
Three different invertebrate families were identified. There is little biodiversity, with no sensitive families present.
As a result, the water quality of Smestow Brook can be described as seriously polluted.
Reasons for the poor water quality at Smestow Brook are
- Urbanisation, development and transport
- Contaminated land
- Sewage discharge
- Pollution from city, industry, transport
- Pollution from wastewater
Below is a Screenshot from the Sewage Map from The Rivers Trust, showing the amount of sewer storm overspill in Smestow Brook in the year 2022.
Sewage Map: https://theriverstrust.org/sewage-map
What can be concluded from this study?
The fact that the biodiversity of macroinvertebrates is affected, clearly shows that pollutants have a significant effect on freshwater and its inhabitants. Vice versa, the biodiversity rate functions as an indicator for how polluted a water body is.
Picture: The Rivers Trust
As shown in the graph, the freshwater biodiversity has decreased by 84% since 1970.
This reflects the detrimental state our freshwater quality is in.
Having healthy freshwater bodies is vital for the ecosystem, allowing wildlife to thrive whilst providing resilience to climate stressors.
Biodiversity is essential, as it covers basic human needs, supplying medicine, food and shelter
Does pollution affect us?
Picture: Sydney Desalination Plant
Water movement can be described in a cycle, as pictured in the image on the right-hand side. Water evaporates due to the sun's heat and condensates into clouds. Once these are full with water, it rains or snow - this is termed as precipitation. Rain and snow can run off into rivers, transforming into lakes and the cycle continues again. A part of the surface water gets filtered through the ground where the groundwater would collect. Groundwater as well as surface water can be used as drinking water.
If pollution is introduced to those water ways, it can get contaminated, containing noxious pathogens. Once this water is used for drinking purposes, water-borne diseases such as typhoid fever and cholera can be transmitted. In the year 2022, a minimum of 1.7 billion people were affected by contaminated drinking water. The results can be fatal. According to the WHO, about 505 000 diarrhoeal deaths are associated with unsafe drinking water yearly.
What solutions are there?
Renaturalise artificial rivers
- enhancing bankside vegetation
- removing invasive plants
- regular litter picking
Solutions against sewage overspills
To avoid floods, a fast implementation of sustainable drainage systems (SuDs) is necessary. There are different types:
- Rainwater harvesting: where a water butt is installed to reduce the amount of water entering the waterways
- Rainwater garden: installing a small depression that contains soil and vegetation, allowing water to be absorbed
Natural flood management
- Leaky dams: placing wood piles to reduce the water speed
- Riperian tree planting: planting trees on the river bankside, blocking and reducing the speed of run offs
- Floodplain restoration: connecting water bodies to wetland, which can store excess water, help to decrease the stress of floods
All solutions create a naturally enriched environment that forms a habitat for a variety of wildlife and can support the filtering of pollutants.
Agriculture
Shifting to organic farming methods, without pesticides and artificial fertilisation, to create a healthy soil that can store plenty of water.
Transparency
Demand more transparency from water companies, including alerts and data of spills in a standardised form. This enhances the data collection and monitoring.
Climate change
Reducing our global footprint, e.g. by changing to renewable energies.
Shifting to a more sustainable water management is an important change we need to make.
Every voice that demands the change is a step towards the right direction.
Now the question is, which river do you prefer?
Here are things you can do to facilitate change:
We cannot be entirely sure how well our wastewater gets filtered. As a rule, flush only human waste and toilet paper. Do not put any paints or cooking oils down the drain. Look online for further guidance on what is allowed in the drainage and what is not. This can also prevent blockage and thus has economic advantages.
Picture: The Rivers Trust
