French police used tear gas on protesters during a large demonstration in the country’s west.
Thousands of people had gathered in Sainte-Soline to protest plans for a new water reservoir.
After clashes broke out at the construction site, several police cars were set on fire.
The unrest comes after weeks of anti-government protests in Paris and other cities over President Emmanuel Macron’s pension reforms.
Though unrelated to the protests over plans to raise the state pension age, the latest demonstration adds to France’s growing sense of public outrage.
Opponents of the irrigation project in Sainte-Soline, near Poitiers, marched in large numbers on Saturday, despite a district-wide ban on gatherings.
The procession began late in the morning, with at least 6,000 people taking part, according to local authorities, though organizers claim the group numbered 25,000.
They are protesting against one of the reservoirs being built in the Deux-Sèvres department, which was developed by a group of 400 farmers to reduce mains water usage during the summer.
Last year’s worst drought on record in France fueled debate over water resources. Supporters of artificial reservoirs argue that they could alleviate shortages during future dry spells.
Opponents argue that the project favors large agricultural producers for crop irrigation in the summer and would not directly benefit the local community.
“While the country rises up to defend pensions, we will simultaneously stand up to defend water,” said the organizers, who gathered under the banner “Bassines non merci” – “No reservoirs, please.”
More than 3,000 police officers were deployed to Sainte-Soline, and officials said at least 1,000 potentially violent protesters had joined the demonstration.
Security forces used tear gas to disperse those who allegedly threw fireworks and projectiles as they approached the fenced-off construction area.
Several people have been arrested, according to officials, and police have seized weapons such as pétanque balls and meat knives.
President Macron stated: “We will never give in to this violence. We do not have the right to use violence in a democratic society.”
Interior Minister Gérald Darmanin described the violence against officers in Sainte-Soline as “unspeakable” and “unbearable.”
Some demonstrators in Sainte-Soline linked this struggle to the nationwide protests against President Macron and his decision to force a pension age increase.
“What is happening today is a convergence of struggles – this struggle for water is similar to the struggle for pensions,” said Benoit Jaunet, a spokesperson for the Deux-Sèvres Peasant Confederation.
“We are experiencing the same level of violence. Our labor and water are being stolen for the benefit of a few. That’s not right.”
Similar marches were held in October.
Protests have swept France in recent weeks. The situation in Paris and other cities improved overnight, but security forces remained on high alert after days of clashes with protesters.
Demonstrations have been mostly peaceful, but violence has broken out in several French cities this week. The entrance to the town hall in Bordeaux was set on fire. In Paris, tear gas was used, and hundreds of fires were started.
However, the Council of Europe, the continent’s leading human rights organization, has warned that sporadic acts of violence “cannot justify excessive use of force by state agents” or “deprive peaceful protesters of their right to freedom of assembly.”
Protesters have been emboldened by the government’s use of constitutional power to impose reforms without a vote in the National Assembly.
President Macron requested that King Charles III’s state visit to France be postponed. The trip to Paris and Bordeaux was scheduled to begin on Sunday.