Plans showing the proposed scheme are on display at Bangor library

The new plans are the result of a study by the Environment Agency Wales and Gwynedd Council of the Afon Adda, and will protect 475 properties.

Businesses in Caernarfon Road have been affected several times by flooding.

"It definitely needs to be sorted out, because we lose trading days when our car park is flooded," said John Roberts of City Electrical Factors.

The business employs nine people and a tributary of the Afon Adda damages the car park each time it overflows at a the culvert at the back of the premises.

"We've improved the culvert ourselves using �10,000 insurance money and we plan to pull down our present premises and erect a purpose-built �500,000 building in its place, so we welcome any scheme to improve matters further," Mr Roberts added.

The Environment Wales study identified problems with the culvert which carries the river under the city.

Larger culvert

The scheme would see larger culvert sections being inserted to improve water flow in some parts; other areas of culvert would be repaired; screens and silt traps would be installed at pipe inlets and a flood "storage area" installed upstream of one inlet at Bryn-Llwyd.

"We hope to start the work at the end of this year and it will take around 15 months to complete," said an Environment Agency spokesman.

"It a very important scheme as it will reduce the risk of flooding to 475 properties in the area," the spokesman added.

A public display of the plans can be seen at Bangor public library from 1000 - 1300 GMT on Wednesday, and then from 1000 to 1700 GMT on Thursday and Friday.