The effects of suction dredging on fish are well described in the peer-reviewed papers Harvey (1986) and Harvey and Lisle (1998) and in the numerous citations in the two DFG review documents (see below “Further Reading”). The draft review report is now out and the information and analysis supports continuing the moratorium on dredging until better regulations and more funding for enforcement are in place (see ). A month later a state law (SB 670) halted suction dredging until DFG completed the court-ordered review of the permitting program and took action to correct any problems that might exist. As a result, in 2009, a court order mandated a stop to all dredge mining until further notice. In the Klamath Basin, the Karuk Tribe became so upset with the impact of dredgers and dredging on fish in their traditional waters that they sued DFG in 2005 for not adequately protecting the environment. Is churning up hundreds of square meters of river bottom worth the 3.4 oz of gold the average dredger collects in a season? Many have more or less recovered from hydraulic and other severe mining of the past but suction dredging could easily reverse their recoveries. The streams that do have been mined repeatedly, creating cycles of mining disturbance. Given the recent trend in gold prices, this could happen again.

In the past, on average CDFG issued about 3400 permits per year although nearly 18,000 were issued in 1980 when gold prices were high.

Because of this, dredge miners must obtain a permit from the California Department of Fish and Game (DFG) for about the cost of a fishing license.

The problem is that suction dredging in streams can harm fish and fisheries, especially salmon and steelhead. So why is there a moratorium on suction dredging in California? A diver vacuums the stream bottom with the hose and the material is flushed into and through the sluice box where the heavier material, including gold, is collected. The device basically is a floating sluice box equipped with a gas-powered pump that sucks up water and gravel through a hose.

A few folks go to a stream on a nice summer day with a portable device to suck tiny amounts of gold out of a stream bottom. Suction dredging seems like a fairly innocent pastime.

2019 california gold mining dredging