Chevron has been ordered to pay more than $744m in damages for destroying parts of south-east Louisiana’s coastal wetlands over the years.

The ruling, which came in the form of a civil jury verdict on Friday, marks the conclusion of the first trial among 42 lawsuits filed about 12 years earlier which alleged that the company’s oil and gas projects have led to the degradation of the region’s wetlands. Among other things, the wetlands play a key role in offering the area a measure of protection from hurricanes.

The jury found that the oil brand Texaco, which is owned by Chevron, violated state regulations surrounding coastal resources by contributing to the disappearing coastline through dredging canals, drilling wells and dumping massive amounts of wastewater into the marsh.

The verdict could prompt other companies to settle the other separate but similar lawsuits. Nonetheless, Chevron’s attorney, Mike Phillips, said that the oil company intends to appeal the verdict.

According to the US Geological Survey, Louisiana’s coastal wetlands are among the most critically endangered environments across the country as they experience more wetland loss than all other states in the continental US combined.

From 1932 to 2016, coastal Louisiana experienced a net change in land area of approximately -4,833 square kilometers, marking a decrease of approximately 25% of the land area at the beginning of that time period.

The canals used to create transportation routes for oil and gas rigs have over the years impeded natural water flow across the wetland ecosystems, according to the Lowlander Center. Additionally, the canals create straight avenues which allow surging ocean waters to bypass the bayous and instead head directly inland during severe weather events.

According to a 1978 Louisiana management law, sites used by oil companies must “be cleared, revegetated, detoxified, and otherwise restored as near as practicable to their original condition” after the companies’ projects end, the Associated Press reports.

The south-eastern Louisiana community of Plaquemines parish filed the lawsuit against Chevron in 2013, asking for $2.6bn in damages at the time. The parish has an additional 20 pending cases against other oil companies.

The jury awarded various compensations to Plaquemines on Friday, including $575m for land loss, $161m for contamination – as well as $8.6 million for abandoned equipment.

Speaking to jurors, Jimmy Faircloth Jr, an attorney representing the state of Louisiana, said that Chevron had said that Plaquemines Parish was not worth preserving, the Associated Press reported.

“Our communities are built on coast, our families raised on coast, our children go to school on coast,” he said. He added: “The state of Louisiana will not surrender the coast. It’s for the good of the state that the coast be maintained.”

According to the state’s Coastal Protection and Restoration Authority, Louisiana could lose up to another 3,000 square miles in the next 50 years.

Phillips said that Chevron was “not the cause of the land loss occurring” in Plaquemines. He said that the law does not apply to “conduct that occurred decades before the law was enacted”.

Phillips called the ruling “unjust,” contending that there were “numerous legal errors.”