The first Yuba-area miners panned for gold in stream beds in the valley, but within a decade large-scale industrial processes replaced solitary prospectors. Mining companies moved from the valley floor into the Sierra Nevada foothills, where miners blasted gravel hillsides with high-pressure jets of water—a process called hydraulic mining. After the miners extracted gold in long wooden sluices, they dumped the remaining sediment slurry back into the mountain valleys. Rivers and streams carried the flood of sediment—called slickens—down to the Sacramento Valley. Anywhere between to of debris was deposited in the Yuba River. The mine waste carried by the Yuba River ended up raising the riverbed (by up to in some cases), causing floods that buried farms east of the town of Marysville with gravel, mud, as well as mercury and arsenic (byproducts of the mining process). As the Yuba River is a tributary of the Sacramento River, much of that debris then found its way to the San Francisco Bay. In Sacramento, the I Street Bridge had to be raised . Lawsuits by farmers curtailed hydraulic mining in 1883, but the slickens remained behind in the river systems.