快猫短视频

Although American environmentalism did not begin to flourish until the 1960s, the movement鈥檚 roots date back to 1878 and a town meeting in Yuba City, California. Not that the assembled townsfolk saw themselves as doing anything so altruistic as protecting nature. Their concern was to save their land and livelihoods from torrents of mud unleashed on them by gold mines upstream. Angry and desperate, they formed the Anti-Debris Association, hired lawyers and went on the offensive. The fight that followed was so bitter it鈥檚 amazing no blood was spilled. At one point, the association armed an anti-debris militia of 70 men 鈥� but law prevailed, and in a decision nearly a century ahead of its time a federal judge decreed that an estimated 45 tonnes of gold must remain in the ground.

IN FEBRUARY 1852, a Connecticut Yankee called Edward Matteson was working his gold claim at a place called American Hill in the Sierra Nevada foothills. There was plenty of gold in the compacted gravel of his claim, but it was widely dispersed and would take months to dig out with a pick and shovel. Perhaps, Matteson thought, there was a better way.

Matteson, like other miners in the early years of the California gold rush, had been using techniques that had hardly changed in millennia. The concept was simple: if you shovelled gold-bearing soil into a sluice box and scoured it with fast-moving water, the lighter sand, gravel and mud would be washed away, leaving the precious metal behind.

Unfortunately, shovelling dirt into a sluice box is hard, time-consuming work 鈥� and dangerous if you are digging into the base of a steep cliff. Matteson鈥檚 brainwave was to attach a canvas hose to a tank of water high above him. Then he could stand safely back and direct the hose so that the water did the excavating and then channelled the debris along a system of ditches into his sluice box.

The Romans had much the same idea: they built dams and ditches to direct water where they wanted it, breaking the dams to create artificial flash floods along the channels. Matteson鈥檚 innovation was to send the water through a nozzle, magnifying the force of the flow and allowing him to direct it precisely where he wanted.

Thanks to his high-pressure hoses, Matteson鈥檚 operation became so efficient he could do several weeks鈥� worth of work in a single day. But the new technique, called hydraulic mining, also sent weeks鈥� worth of sediment downriver each day.

Word spread and soon hydraulic mining was booming. Most of the early mines were small and their environmental effects predominantly local. And in the early 1860s severe drought forced many to close. But when the rains returned, so did the miners, this time backed by wealthy investors from as far away as England.

鈥淗ydraulicking鈥� worked best along an 80-kilometre belt of the Sierra Nevada at elevations between 1200 and 1500 metres, where huge deposits of gold-bearing sediments had accumulated in ancient streambeds. There were mines everywhere, but by far the largest was Malakoff Diggins, which was so efficient that it could profitably mine sediments containing only a few pennies鈥� worth of gold per cubic metre.

The mine was run by the well-financed North Bloomfield Gravel Mining Company, which ploughed $3.5 million into the operation. The Diggins eventually produced more than 6 tonnes of gold.

Today all that鈥檚 left at the site is a 250-hectare pit 200 metres deep. But at the peak of operations, crews laboured day and night in the red-tinted gravels with hoses whose 鈥淟ittle Giant鈥� nozzles could shoot 20-centimetre-thick jets at speeds of up to 50 metres per second 鈥� enough force to kill any miner who got in the way. In 1879 a reporter from the San Francisco Bulletin spoke of huge rocks being washed away 鈥渓ike chaff鈥�, with 鈥渁 cloud of red foam鈥� hanging above the points where the water hit the cliff. When water wasn鈥檛 enough to do the job, entire hillsides were loosened with gunpowder 鈥� sometimes 15 to 20 tonnes of rock in a single blast.

When a US federal judge called Lorenzo Sawyer visited the site in the 1880s, he too was impressed. 鈥淭he excavating power of such a body of water, discharged with such velocity, is enormous,鈥� he wrote. He was particularly amazed by the mine鈥檚 night-time operations, conducted under 鈥渂rilliant鈥� lights that ran on hydroelectricity. 鈥淎 night scene of the kind, at the North Bloomfield mine, is in the highest degree weird and startling, and it cannot fail to strike strangers with wonder and admiration.鈥�

鈥淏y 1880, 鈥榟ydraulicking鈥� had buried 6000 square kilometres of farmland鈥�

But Sawyer wasn鈥檛 there to admire the scene. He was there because of where all that water, mud and silt was going. The first part of its journey was along a 3-kilometre tunnel through a mountain. The tunnel was effectively a vast sluice box that caught as much as 90 per cent of the gold. The debris, however, carried on into the Yuba river and towards the farmlands below.

In 1880, California鈥檚 state engineer had estimated that 6000 square kilometres of farmland had been buried by mining debris. Sand bars had sprung up in rivers all the way to the coast. Hardest hit were the towns of Marysville and Yuba City, directly below the mines. As debris built up in the riverbed, the water rose so fast that the levee builders could hardly keep pace. But by now the people of Yuba City were fighting back. In 1878 they had banded together to form the Anti-Debris Association and sued the owners of the mine. Six years later, a panel of judges headed by Sawyer decided the case.

Judge Sawyer鈥檚 56-page ruling is a litany of environmental horrors, but the worst were his projections for the future. So far, the North Bloomfield mine had dumped 90 million cubic metres of debris into the Yuba river. About a quarter of that had reached the lowlands. The rest was still perched upstream, clogging some canyons to depths of up to 50 metres and creeping downward with each spring flood. If there was a really big flood, there was a chance the whole lot would come sliding downriver.

Worse, Sawyer estimated that there were 500 million cubic metres or more of gravel still to excavate. There was no choice but to shut down the mine under the ancient law of nuisance, which prohibits using your property in ways that damage someone else鈥檚.

Sawyer didn鈥檛 ban hydraulic mining outright, though. He ruled that if the miners were to continue, they must find a way to keep the debris on their own property 鈥� and prove in advance that it worked. The miners appealed for leave to experiment with remediation techniques while continuing their operations. But Matthew Deady, one of Sawyer鈥檚 fellow judges, gave that idea short shrift. Asking the people in the valley below to put up with that, he said, 鈥渕ay be likened, at least, to living in the direct pathway of an impending avalanche鈥�.

Sawyer鈥檚 judgement was remarkable because it pre-dated America鈥檚 best-known environmental rulings by more than 80 years. The stakes were enormous: the judgement would determine California鈥檚 future as either an agricultural state or a mining state. But Sawyer didn鈥檛 seem to see it as a trailblazing decision. He was simply applying established law, albeit on an unprecedentedly large scale.

It took years to force out miners who flouted the ruling, but the court鈥檚 decision effectively killed off hydraulic mining in the California goldfields. Hydraulicking itself has never died: it has been used elsewhere to mine everything from coal to rubies and even aluminium. The difference is that today鈥檚 mines exploit higher-grade ores, which make it economical to trap the tailings and recirculate the water in closed loops.

The hydraulic miners鈥� legacy still surfaces from time to time in California鈥檚 courts. In 1986 a flood breached levees built nearly 100 years earlier out of debris washed down from the North Bloomfield mine, resulting in lawsuits over whether such materials were adequate for flood protection. And in 1995 the California supreme court took on the tricky question of who owns those sandbars created by the shifting sediments from the old mines, some of which are now prime sites for urban development.

But nobody ever found an environmentally sound way to reopen the Malakoff Diggins. Today it鈥檚 a little visited state historical park, even though, if Sawyer鈥檚 back-of-the-envelope estimate is correct, gold worth $650 million remains in the ground.