US President Donald Trump has been given the green light for a scaled-down sea wall at the golf course his company owns in the west of Ireland that environmental groups say could damage protected wildlife habitats.

The Trump International Golf Links Doonbeg, owned by the Trump Organisation, received permission for two sea barriers of 630 metres and 260 metres in length, Clare County said, a year after it rejected plans for a much larger 2.8-kilometre wall.

Residents and environmental groups objected, saying the wall — which is designed to protect the golf course from coastal erosion — could alter the coastline at other points and harm wildlife.

“It’s disappointing. We should be altering the golf course not the coastline,” said Green Party leader Eamon Ryan.

He said he would be surprised if the decision is not appealed.

Trump has spent $US330 million ($462 million) buying golf courses and land to develop since he began investing in golf in 1997.

The environmental group Save The Waves collected 100,000 signatures opposed to the initial development plan.

“You can’t ignore (the fact that) the owner in this case is so notorious but the concerns were there long before he bought the course,” Mr Ryan said.

The general manager of the golf club said he was pleased with the decision and thanked the council for its “foresight”.

“This decision demonstrates the council’s commitment to support local business and protect the economic future of the region,” general manager Joe Russell said in a statement.

The original plan envisaged a 2.8km armourstone wall up to 20 metres wide and five metres above the water line between the sea and the dunes and sparked a campaign by environmental groups and locals to protect the beach.

The new plan provides for a less visible sheet metal piling and rock armour at two points above the high water mark.