The State Barrier Fence Esperance extension has cleared the final environmental approvals.
Work on the extension is now set to begin by June.
The 660 kilometre extension will help farmers in Ravensthorpe and Esperance with the scourge of wild dog predation and emu and kangaroo incursion.
The state government allocated $6.9 million, the Esperance Shire contributed $1.4 million, the Ravensthorpe Shire contributed $280,000 and the federal government allocated more than $1.95 million to the project.
The Department of Primary Industries and Regional Development has started a training module aimed at upskilling Esperance Tjaltjraak traditional owners to complete fencing works.
WA Agriculture Minister Alannah MacTiernan said the approval meant construction could start soon.
"We are also ensuring that work on the project delivers real employment and training benefits to local Aboriginal people," Minister MacTiernan said.
"Pre-construction survey work is almost complete and we look forward to celebrating with the Esperance and Ravensthorpe communities when the first post hits the ground."
Esperance Biosecurity Association president Scott Pickering has been fighting for the project for about 19 years.
"It's great because we have been fighting for this for a long time and we were told 'it's never going to happen, it's too hard'," Mr Pickering said.
"We kept persevering and persevering and we've worn down a few politicians.
"It's going to get started after all these years and it's going to happen at last."
Mr Pickering said the association's view was that Esperance farmers should be protected by a fence given they were on some of the most productive farming land in the state.
"It's a pretty big thing for Esperance," he said. "The more livestock and grain production means more people will spend money in town."
The Wilderness Society in WA were one of two groups that appealed the EPA's decision to approve the project in November 2018.
The society expressed disappointment that both appeals were dismissed. State director Kit Sainsbury said the project was a "potent cocktail of doom" for the long term viability of the critically endangered Western Ground Parrot.
"Alternative cost-effective methods for wild dog control are available to the state government which doesn't require this frankly archaic barrier," Mr Sainsbury said.
Mr Pickering called the two groups "serial appealers" and expressed frustration that they had held the project up for four months.