"When they dredge sand, it is kicked up, covers the reef and suffocates it," says Kate Sadie*, a Diani resident who led the fight in court.
"The water was not clear, so the turtles could not feed on the grass. Many got weak and died; all the fish went away," says Said Hamisi Mwaito, a fisherman and turtle conservation volunteer.
"Beaches would have been lost … tourism would have been impacted, fishermen's livelihoods lost," says Felix Mibikira, a lawyer who represented Diani residents in court.
In February 2016, the National Environmental Tribunal ruled that a proper Environmental Impact Assessment (EIA) hadn't been undertaken and banned dredging.
Mibikira's team were able to prove in court that EIA surveyors visited the beach, but never went underwater. CRBC lodged an appeal and the case is ongoing.
Fisherman and turtle conservationist Said Hamisi Mwaito on the Kenyan coast says coconut trees have drifted away in the water due to dredging. "It's very sad," he says.Local Makueni farmer and activist Anthony Mua Kimeu says sand helped people survive droughts. "You hear people say, 'If I'm harvesting sand, I'm not harvesting water,' but it is really the opposite," he says.
"The pressure for sand harvesting to continue is huge," says Gino Cocchiaro, a lawyer with the nonprofit organisation Natural Justice.
In past year, harvesting has taken off in Makueni.
Atanas Maina, managing director of Kenya Railways, said in a phone interview that among other counties, CRBC, from 2014 until earlier this year, bought river sand from traders in Makueni who had trading licences "with the total knowledge of the county government". Regarding the environmental problems in Makueni caused by sand harvesting, Maina said if they were given harvesting licences they would also carry out restorative work.
The sand harvesters
If some traders have licences, many do not. Along a riverbed in Makueni, men in faded, ripped shirts spend their days illegally digging sand and flinging it onto piles in the baking midday sun.
On an average day, 10 trucks come and go from this stretch of river removing about 100 tonnes of sand. There can be up to 20 mining sites on each of Makueni's rivers.
Richard Mutinda, 40, has harvested sand for more than one year.
"I look for other jobs because I know the sand will run out," he says, leaning on his shovel. "I know that with the sand goes our water. I know that water is life, but what choice do I have?"
The truck drivers pay him 500 Kenyan shillings (about $5) a day. "I need to get paid so I can feed my family," he says.
"[The cartels] oppress us," Mutinda says. "They get the money but we do all the work, and put ourselves in danger doing it."
Jobs are hard to come by, so many men start mining illegally, causing rifts within communities.
Given the lack of opportunities, Mutinda says he understands why miners use violence when residents try to stop them. "Sometimes, we have to be violent," he says.
He believes better regulation around pay and working conditions would stem these tensions. "It is not a good job. It is not safe," he says, referring to the deaths caused by careless, speeding truck drivers.
Last December, a truck on a riverbed crushed 16-year-old miner Kioko Musyoka.
"Many people [who are] sand mining down the river are never seen again," says his mother Theresia Musyoka, sitting outside her home made of sand.
Across Makueni, residents, government officials and law enforcement officers told Al Jazeera that at the root of illegal sand harvesting operations are corrupt officials and powerful cartels.
Local Makueni farmer and activist Anthony Mua Kimeu talks about sand harvesting violence and the loss of water in the county. Kimeu believes the government "must come up with a clear solution, because here it's a matter of death and life".
The sand cartels
Cartels usually own the trucks, hire drivers to collect sand from labourers like Mutinda, and take the lion's share of the profits when selling to construction companies.
"We know cartels run the sand harvesting because they don't hide. They proclaim it," says George Mbala*, a county government official.
Mbala says one known individual "runs an illegal sand harvesting business and hires others to be involved. He harvests the sand, protecting his lorries with guns. He goes [to] the river, he's armed; he threatens to shoot people," Mbala says. "Once, we had a public meeting with him. The public pointed at him and said, 'You are doing this' and he didn't deny it."