Healthy rivers

Water is the lifeblood of all life – this is what Tom Hartland Smith told me on the podcast.  Tom is a senior catchment restoration officer with the Severn Rivers Trust.  He presented me with a fascinating insight into rivers.  Rivers in England provide two-thirds of the country’s water supplies, support a tremendous variety of wildlife and offer a place for relaxation and fun.  It seems humans are messing with every aspect of nature, quite often to its detriment; water has not evaded this interference!

The Rivers Trust

The Rivers Trust is the umbrella organisation for 65 member Rivers Trusts across Britain, Northern Ireland and Ireland.  They are river and catchment conservation experts.  The trusts envision wild, healthy, natural rivers to be valued by all

Healthy Rivers

Rivers are channels of freshwater that flow towards the oceans, lakes and seas.  Unfortunately, no river in England passes chemical standards and only 14% pass for good ecological health.

janet's foss, malham, yorkshire-2451389.jpg example of a healthy river

There are several ways to assess rivers for health:

  1. Water quality – analyse for pollutants such as pesticides, sewage-related compounds and heavy metals.  
  2. Water quantity – too much water from heavy rainfall can cause rivers to rise exponentially, resulting in the ejection of juvenile fish and river bed disturbance.
  3. Available habitat – wildlife and fish abundance is a good indicator of a healthy river.  

River hazards

Farming practices can impact rivers negatively.  Here are some examples:


  • Farmers are financially dependent on their land.  Consequently, they may not rest land as much as they would like.  Overuse leads to degraded soils, which hold less water.  When it rains, water will run off into rivers quickly.
  • Cattle can compact the top layer of the soil.  Again when it rains, water runs off into the catchment. 
  • Lack of fencing between rivers and farmland can result in livestock trampling vegetation and polluting the river with manure.
  • Animal waste from ineffective management can end up in rivers.  In 2023 intensive poultry production has been associated with downgrading the river Wye.
  • Pesticide and herbicide usage on crops can run off into rivers with a lasting impact on water courses.
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The UK sewerage system reflects its Victorian architecture (this article charts its history).  Since its inception, the population has increased and heavy rainfall events are more frequent owing to climate change.  During these events, permitted discharges by water companies avoid sewage backing up into buildings.  Outside of these events, water companies risk fines for making unpermitted discharges. Discharges, permitted or otherwise, pollute rivers and threaten wildlife and human health.

Urbanisation and transport 

There are various ways we affect rivers deleteriously in these sectors, such as:

  • Hard surfaces – increasing from building new houses and people switching their lawns/gardens to tarmac or astroturf. A rise in hard surfaces causes more water to flow into rivers.  
  • Misconnections in buildings – there are two drainage systems. The wastewater sewer takes water from appliances, toilets, sinks and showers to wastewater treatment works before being released into the environment. The surface water sewer takes rainwater from roof and ground runoffs to enter directly into rivers or streams. It’s thought up to 500,000 houses are plumbed incorrectly, meaning water for sewerage ends up in rainwater drains. 
  • Road water runoff – vehicles deposit damaging chemicals (e.g. hydrocarbons) that threaten river health during rainfall.  

Climate change

Increasing greenhouse gases are changing our climate.  We are now experiencing more extreme weather.  This weather can impact rivers negatively in various ways, including:

  • Longer dry spells result in the soil becoming hard and impervious. When rain finally pours, it’s often heavy and risks river health through flooding.
  • Higher temperatures over an extended period cause river temperatures to rise from 10-12°C, the optimal temperature for river species. Temperatures rising to 20°C threaten their survival, a possible contributing factor to salmon numbers decline.

Improving river ecosystems

Although there are a variety of threats to river ecosystems, there are numerous ways to tackle the problems.  Here are some examples:


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The Severn Rivers Trust has farm advisors who work with landowners to reduce water flow and improve water quality.  The trust can facilitate broader learning, particularly around soil quality and offer soil analysis.  Strategies for improving soil quality will benefit rivers and crop/grass yields. 

The advisors may encourage fencing to protect the river habitat from livestock or suggest a buffer strip to provide a space for nature.  A functional riparian habitat provides shading from high temperatures and flood resilience by slowing water flow.


This serious pollution problem requires the government to introduce solid policies and water companies to make substantial investments.  Individually, everyone can make a difference by not throwing inappropriate items down their toilets, such as wipes and sanitary objects.

At home

People can be mindful of the surfaces they lay down when renovating their homes.  Permeable surfaces rather than tarmac can alleviate excessive runoff into rivers.  Installing water butts has a similar benefit through collecting rainwater and using it for watering gardens during dry spells..

For the misconnection issue, Tom suggested a policy change could solve it.  A mandatory connection check when selling a house would ensure misconnections are discovered and fixed.

Alleviating physical barriers

Barriers such as old water mill infrastructure and weirs are barriers to many species. For example, Salmon live and feed at sea but spawn in fresh water. When they are ready to re-spawn, they return to their place of birth. During this trip, they may have to cross numerous man-made features. They rely on energy reserves; multiple structures can challenge their survivability. Eels are in a similar position, as they migrate approximately 3,000 miles from the Sargasso Sea, only to find they get thwarted by river barriers.

Removal of some barriers is an option. Those offering historical interest or community purpose require mitigation. One such example is the Unlocking the Severn project. It is a collaboration between Severn Rivers Trust, Canal and River Trust, Environment Agency and Natural England, and funded by Lottery money. They have constructed the Diglis Fish Pass, enabling species to navigate the barrier. An underground viewing station enables members of the public to see the fish in action.

The future of river health

As always, with environmental matters, the picture is complex.  Despite many challenges, with The Rivers Trust advocating change, and a range of available solutions, the outlook can be positive for rivers, nature and human health.