LWERA WETLAND, Uganda -- The excavator grunts in the heart of the wetland, baring its teeth. There are trucks waiting to be loaded with sand, and more almost certainly on the way.
This is how it is here daily in Lwera -- a central Ugandan region on the fringes of Lake Victoria: a near-constant demand for sand that's exerting pressure on a wetland that's home to locals and animals and feeds into Africa's largest freshwater lake.
Lwera is a breeding ground for fish, serves as a stop for migratory birds and can store vast amounts of planet-warming carbon dioxide underground. The wetland stretches more than 12 miles astride the highway from the Ugandan capital Kampala into the western interior. It has long been worked over by sand miners, both legal and illegal, motivated by demand from the construction industry.
Now, all known corporate operations within the wetland have authorization to be there, giving them a measure of legitimacy that's frustrating environmental activists, local officials and others who say the mining activities must be stopped because they degrade the wetland.
They charge that while the companies are there legally, their activities are in many ways unlawful.
Locals in Lwera's farming community say they reap misery, complaining that mining creates few jobs and ruins the land.
Ronald Ssemanda, a local village chairman, pointed to bushy land fenced off with roofing sheets that he said had been cratered badly by sand miners.
"There is no way I can even talk to them," said Ssemanda, referring to owners of mining operations he deems too powerful.
Ssemanda is no longer so vocal in his criticism. He said the matter "is above us."
Sand mining -- mostly for use in the construction industry -- is big business, with 50 billion tons used globally each year, the United Nations Environment Programme said in a report last year. It warned that the industry is "largely ungoverned," leading to erosion, flooding, saltier aquifers and the collapse of coastal defenses.
Healthy wetlands can help control local climate and flood risk, according to UNEP.
In Uganda, an ongoing construction boom mirrors trends in the wider region. Riverbeds and lake basins -- public property -- are often the scene of mining operations, although there also are private estates dug up for sand.
But while all wetlands around Lake Victoria are under threat from sand miners, the eponymously named sand from Lwera is favored among builders for its coarse texture that's said to perform better in brickwork mortar.
Some builders are known to turn trucks back, rejecting the sand if they can't prove by feeling it that it's Lwera material.
At least two companies operate formally within Lwera: the Chinese-owned Double Q Co. Ltd. and Seroma Ltd. Both frequently face questions over their allegedly destructive activities there, and members of a parliamentary committee on natural resources threatened to shut them down after an unannounced visit earlier this year.
Both companies were open for business when The Associated Press visited earlier in April. Double Q officials declined to be interviewed at the site and didn't respond to questions.
A representative of Seroma Ltd., production manager Wahab Ssegane, defended their work, saying they have a permit, their operations are 6 miles from the lake and that they follow guidelines from the National Environment Management Authority or NEMA.
NEMA has banned dredging within Lake Victoria but permits sand mining in the wetlands.
"Otherwise, you would have to import sand," said NEMA spokeswoman Naomi K. Namara. Companies caught degrading the environment face stiff financial penalties, she said.
But activists and some locals say no company should be permitted to operate in Lwera, even if it somehow is able to curb environmental concerns.
One key concern relates to the equipment used. Companies are permitted to dig 13 feet into the earth, but some dredging vessels are retrofitted at site to be able to dig deeper, according to some officials at the scene.
"They don't have permits to use those dredgers," said one official who's part of a local government team collecting taxes from miners, who spoke on condition of anonymity to avoid retaliation. "The dredgers are going [40 feet] underground," he claimed.
It's hard to refill the open spaces when miners dig that deep, leaving depressions in the earth, he said.
When the pits are not refilled the open spaces naturally fill up with water that then spreads, occasionally flooding people's gardens and homes, said resident Sandra Buganzi.
"The sand people came and dug up the sand and brought for us water, which started going into people's homes," she said. "I feel very bad, and I feel anger and hatred in my heart."
As Buganzi spoke, a neighbor, Fiona Nakacwa, gripped a garden hoe and paved a way for water away from her home.
She worried she could be forced to leave her neighborhood.
"Before they started digging sand, there was no water coming here," Nakacwa said. "This place was dry and there was a garden. I've lived here for seven years and there never used to be water."
At least 10 of her neighbors have since relocated, pressured by flooding.
"We are still here because we have nowhere else to go," Nakacwa said.
Companies -- often with soldiers or police manning the gates -- operate virtually under no supervision and local officials have been reduced to mere spectators, according to some officials and residents who spoke to the AP.
Charles Tamale, mayor of nearby town Lukaya, said they were powerless to do anything when companies presented their papers.
"It needs some control, but the government licenses these guys," he said. "But in fact what they are doing you cannot say it's legal ... they are mining and not putting up preventative measures."
Jerome Lugumira, the NEMA official whose docket includes looking after wetlands, said he wasn't available for comment.
Activist David Kureeba, who tracks mining activities in wetlands, said NEMA was too weak to resist "pressure from the middlemen in government who bring investors" into the country. Lwera should be out of reach to all investors, said Kureeba.
No matter the economic rewards, "NEMA commits a mistake to allow sand mining in such an important ecosystem," he said. "They had better cancel all the leases."