KEEP THE MERSEY FLOWING!

Tidal power generation in the Mersey Estuary: Barrage options

 

MECGs Response to Peel Energy’s public consultation

 

 

We accept that tidal power may have a place in the array of renewable electricity generation schemes.  However, we strongly believe that a barrage across the Mersey estuary should be ruled out as it would be highly damaging to wildlife and habitats.  Only the less harmful schemes should be considered, such as ‘fences’, ‘gates’, ‘lagoons’ and SMEC (Spectral Mass Energy Converter) devices. These would involve, at most, the creation of a partial barrier and thus would not damage the Mersey’s ecology as much as a barrage right across the estuary.  

 

Once a barrage is in place sedimentation patterns will change with altered water velocity patterns, bringing about severe siltation with the possibility of costly dredging.

The reason for the choice of the barrage option is clearly that it is thought it would generate the most energy but wildlife and habitats should not pay the price for the extra energy obtained.

 

Wildlife, chiefly waders and ducks, would suffer because of the loss of feeding and roosting habitats. The estuary’s value for birds is fully recognised at national and international level since most of it is designated as a SSSI, SPA and Ramsar site. 

 

There are also concerns for fish.  After the Mersey was cleaned up fish returned, including salmon. Due to the pressure of the turbines on each tide, fish would suffer damage and die.

 

Sedimentation patterns will change with reduced water velocity, bringing about severe siltation.  At the same time, there may be increased erosion of the banks, causing flooding of land and properties and intrusion of sea water into the groundwater system. Below the barrage, both in the estuary and in Liverpool Bay, sedimentation and erosion may be altered in ways that are

       difficult to predict

 

As for a tidal barrage reducing the emission of carbon dioxide we would dispute this.  Intertidal mudflats - as long as the tides

       cover them intermittently –actively lock away carbon dioxide in their sediments. In addition, there is the huge amount of

       carbon dioxide generated in the building phase to be taken into account when the carbon dioxide balance is calculated?

 

 

  

 

Teal  -  over 150 birds gathered off Pickerings Pasture in December 2010