Complex sentence: Responsibility and co-ordination of the belt lie with local unitary and district councils as these are the local planning authorities, however the area is largely covered by the West of England Combined Authority which has some responsibilities for the infrastructure of the area.
Split into simpler sentences: Responsibility and co-ordination lies with local unitary and district councils as these are the local planning authorities. The area is largely covered by the West of England Combined Authority which has some responsibilities for the infrastructure of the area.