What is Hydraulic Mining?

Developed by Edward Matteson during the middle of the 19th century, hydraulic mining is a process that uses water to move sediment and dislodge rock material so that the location can be stripped of valuable ores and minerals. Also referred to as hydraulicking, the process of hydraulic mining relies on using a large amount of pressure to drive the water through the mine shafts, effectively clearing the way of debris and sediment deposits that would take long periods of time to remove and sift through. Here is some information on the history of hydraulic mining and some examples of how the technique is still used today.

First developed as a modern technique in 1853, hydraulic mining was implemented as a means of sifting through rocks and sediment to find traces of gold ore. The usual application was to construct paths and canals that would free water from the higher mountain ranges and store the collected water in ponds located several hundred feet above the terrain that was to be mined. The water would be directed from the pond into a channel that would narrow as the flow of water moved closer to the area that was to be mined.

The combination of gravity, water weight and the narrowing channel created jets of water that could effectively cut into the land, washing away loose sediment and rocks. The resulting pressure could easily be used to mine entire hillsides at a pace that such methods as sluicing and pan mining could not match.

While hydraulic mining was a hugely profitable means of locating and acquiring gold ore, the process left a great deal of damage to the environment. Sediment and rocks that ran off from the sides of the hills found their way into rivers that ran into the flatlands of California, where the collection of sediments often changed the flow of the rivers and created flood conditions that were capable of devastating whole communities. The collection of sediment also altered the riverbed, making it harder for boats to use river transportation for delivery of goods.

In time, farmers and others began to demand that hydraulic mining for gold cease and desist. Lawsuits led to regulations on the practice of hydraulic mining being enacted by the United States Congress in 1893. However, as mining became less profitable, the use of hydraulic mining began to decline in general.

Today, hydraulic mining is still used in some places, although not always for the purpose of looking for valuable metals. One of the most common uses today is in excavations. Hydraulic mining is an excellent way to smooth terrain for building purposes, and the collected sediment is often relocated for use in landscaping endeavors. Still, there are some instances around the world where hydraulic mining is still used to secure precious metals. However, the lessons of California were learned well, as just about application of hydraulic mining today includes the efficient collection and redistribution of sediment in ways that does not adversely impact the environment.