Campaign against the levels motorway

The Wildlife of the Gwent Levels


The Gwent Levels is the largest area of its kind in Wales and is of acknowledged UK wide significance for its wildlife and archaeology. It is so valuable for wildlife the majority of it has been designated under six Sites of Special Scientific Interest (SSSIs). The Levels qualify as SSSI on the basis of their rare wetland plant and invertebrates, but they are also home to other wetland creatures such as otters, water voles and breeding waders. The proximity of the site to the internationally important Severn Estuary and River Usk add further value to this wetland complex.

Several nature conservation organisations have identified the whole of the Gwent Levels as an important landscape for wildlife.

If the M4 road goes ahead, one of the UKs largest surviving areas of ancient grazing marshes and reen (drainage ditch) systems with its associated, unique, wildlife will be irreparably damaged. Damage would not be limited to direct loss of habitat where the road is built; the motorway would create a barrier preventing the movement of wildlife between the SSSI areas not under concrete. In addition, the road will impede water movement between these isolated pockets and this could have a significant effect on the wetland habitat depends on. The pollution that runs off the road into the reen system could seriously affect the water quality that is so vital for the important inhabitants of the wetlands.

The natural features of the Gwent Levels that would be affected include;

Mammals and Birds

  • Otter numbers in the UK were at an all time low because of water pollution and hunting, but have significantly recovered and are now frequent on Levels. But as the population expands, the biggest threat is from road kills which will increase if a new M4 is built.
  • Water voles are now scarce and localised but the levels is still a key area for this seriously declining species
  • Breeding waders lapwing, snipe, redshank and curlew all breed locally across the Levels, with further species on the Newport Wetlands reserve.


  • 144 Nationally Notable or Red Data Book invertebrate species have been recorded from the Gwent Levels.  The groups of water beetles, dragonflies & damselflies are features of the SSSI designations. 

Flowering Plants

The Levels support the nationally scarce rootless duckweed (Wolffia Arrihiza).  This is considered to be the worlds smallest flowering plant and occurs no where else in Wales. Other significant plant species include:

  • Brackish water-crowfoot
  • Hairlike pondweed
  • Blunt-leaved pondweed
  • Small pondweed
  • Lesser pondweed
  • Narrow-leaved water-plantain
  • Whorled water-milfoil
  • Fine-leaved water-dropwort
  • Meadow thistle
  • Blunt-flowered rush
  • Tussock sedge
  • Arrowhead
  • Soft hornwort
  • Grass vetchling
  • Meadow rue
  • Flowering rush
  • Water whorl-grass
  • Greater duckweed
  • Great yellow-cress
  • Horned pondweed

Development Pressure

The Gwent Levels have suffered from severe pressure from development which has continually eroded the levels, with development schemes such as the Gwent Europark which has resulted in the removal of hedgerows, mature trees, reens, field ditches and wet meadows. If the proposed dual carriadgeway becomes a reality, it will open up the Levels to more and more development, leading to further wildlife losses.

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