Mersey barrage scheme

Mersey barrage scheme

Steve Rotheram, the Liverpool City Region Mayor has announced plans to look again at the feasibility of constructing a Mersey Estuary Barrage in order to create green energy and provide a stimulus for employment and investment.

Cheshire Wildlife Trust is keen to support renewable energy schemes in the right place, but a barrage scheme in the Mersey Estuary has the potential to cause significant environmental damage. The Mersey Estuary is a complex and dynamic habitat of inter-tidal mudflats, saltmarshes and rocky shores supporting tens of thousands of feeding birds. Many of the birds arrive here from northern Europe, Canada and Siberia, using the estuary as a stop-off to refuel on the worms, shrimps and shellfish that are found on the mudflats. The importance of the estuary is recognised internationally and it currently benefits from the highest level of European protection.

Over the past few decades the river Mersey has benefitted from vast improvements in water quality, which has in turn enabled the return of fish, such as sea trout, eels and lamprey. After many years of absence salmon are now back in the estuary and are migrating upstream to spawn in the headwaters of the river Goyt in the Peak District.

Potentially irreversible changes caused by the construction of a badly designed barrage, such as the design that was put on hold in 2011, could put at risk this incredibly important ecosystem and the survival of the species that live there.

We have the technology and the knowledge to not destroy the environment in the pursuit of renewable energy; however if we do it wrong we could end up destroying the very things we are trying to protect – biodiversity and our quality of life.

How you can help?

We would encourage you to write to your MP about this issue (find out who your MP is here), or/and e-mail Steve Rotheram, the Liverpool City Region Mayor at

You might to use some of these facts below (and some of your own opinions) when writing:

  • We need to know more about the plans to harness the tidal power of the estuary. If this involves a barrage or any structure that reduces the intertidal area in time or space it would have a devastating effect of the environment. 
  • Such a tidal barrage is not “green” energy, if by green you mean good for the environment. A barrage on the Mersey would have immediate and devastating impacts on the internationally important wildlife. It is not “sustainable” either as sustainability is supposed to balance social, environmental and economic interests, not sacrifice one for the other.
  • The Mersey Estuary is a truly wild place in amongst heavily developed and densely populated areas. In the Mersey Estuary, unlike many other estuaries like the Dee or Ribble, the river has never been modified or had its channel straightened. The river is very dynamic and can meander and move naturally creating extensive areas of food rich mudflats and saltmarsh. People can walk along its north shore along the Mersey Way and appreciate an untamed wilderness.
  • The Mersey estuary is one of the best wetlands in Britain for water birds.
  • It is protected by national legislation, as a Site of Special Scientific Interest.
  • It is protected by the European Birds Directive as a Special Protection Area. And it is a Ramsar site which is a worldwide treaty established by UNESCO in 1971 and signed by 169 countries pledging to protect their most important wetlands. The Mersey Estuary is thus internationally important.
  • It is the best place in the UK for the small wading bird called dunlin (over 68,000 have been recorded) and shelducks.
  • It is also internationally important for ringed plover, black-tailed godwit and redshank.
  • It is nationally important for grey plover, lapwing, ruff and curlew.
  • Internationally important means it is host more than 1% of Europe’s population and nationally important it holds more than 1% of the UK’s population. For dunlin 68,000 is 20% of the UK’s birds.
  • The Mersey also holds the record for the most number of teal and pintail ever seen in the UK.
  • All of these birds rely on the intertidal area which are a very rich food source.
  • Any barrage that will reduce either the amount of intertidal area or the amount of time it is exposed and available to birds will have an impact on these birds.
  • The real untapped potential for the Mersey is its potential as a wildlife visitor attraction. There are no publicly accessible nature reserves within the Estuary. This is surely a missed opportunity.
  • There have been proposals before for a barrage but they meet a problem; to preserve the value of the estuary to birds you need to provide mitigation. Recreating intertidal areas, in particular mudflats, is extremely expensive and technically almost impossible to do with any certainty and there are very few, if any, suitable sites as most of them have been developed or “reclaimed” in the past.

In these challenging times our work will still continue to defend local wildlife

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