WIGAN Council could employ four people and spend  £300,000 to tackle destructive plants including Japanese knotweed, Himalayan balsam and giant hogweed.

Concerns over the spread of Japanese knotweed, Himalayan balsam and giant hogweed will see £105,000 spent for each of the next three years, if recommended proposals are voted through.

The town hall says it will be an "invest to save" scheme as the authority would be  liable to pay significant insurance costs should the plants encroach onto private land and cause damage.

Their detrimental impact on the borough’s environment and the potential to hinder housing developments are also major factors in the strategy, according to a new report.

The proposal will be discussed by members of the town hall’s confident council scrutiny committee next week.

If approved, the funds will pay for four full-time officers and two vehicles to tackle the spread of the invasive, non-native species (INNS) with 162 hectares across more than 700 borough locations said to be affected.

A list of priority sites will be drawn up to offer the "strongest risk mitigation strategy" for the town hall.

The report reads: “Treating every single incidence of INNS is neither affordable nor necessary, except in the case of giant hogweed (because of its severe effects on people and animals).

“The value of eradication should be considered against any potential liability from encroachment in private land, impact on land for development and impact on biodiversity.”

Other options considered by officers include only carrying out reactive works, which would leave the town hall open to third party insurance claims but would be cheaper, or outsource to a private contractor, which could cost millions of pounds.

The plans have been developed by the council’s corporate land management team along with counterparts from outside groups such as Lancashire Wildlife Trust and the Canal and Rivers Trust.

Officers have warned that Network Rail was successfully sued last year by two neighbours and ordered to pay treatment costs in addition to compensation for the loss of value to their properties, because of the spread of INNS.

The report reads: “The council is in the same legal position as any other landowner and may therefore be potentially liable for natural hazards (such as invasive weeds) that encroach onto neighbouring land.”

Councillors will also be informed that the presence of INNS can delay housing developments by several years.

And they have a "direct impact on biodiversity as they hinder and curtail the growth of other, native species".

Japanese knotweed can grow rapidly and can cause damage to house foundations.

Himalayan balsam has dense foliage which stifles native plants and is often found on river and canal banks. When it dies back in winter it can leave the banks susceptible to erosion.

Giant hogweed can be a hazard to humans and livestock as its sap can cause painful blisters.

The confident council scrutiny committee will meet on Monday, November 19.