Mining Gravel and Protecting Streams

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Published on: Oct. 2, 2001

Last revision: Nov. 9, 2010

not change its course as a result of the mining. It will also prevent eroded material from causing siltation problems downstream and will protect the roots of plants that prevent bank erosion.

When gravel mining, never relocate or straighten stream channels. Doing so can cause instability that leads to excessive erosion of the streambed and banks.

Once mining is finished, unused material should be returned to the removal site and smoothed to mimic the original contours of the bar. Unused material should not be stockpiled in the channel, placed against the stream banks or deposited in a stream side wetland. Stockpiling material in the channel obstructs high stream flow, which can increase stream bank erosion. Pushing material against stream banks may actually increase erosion at the site. Remember, any sand, gravel, silt or other sediment eroded from one place will deposit somewhere else and may cause you or your neighbor serious problems.

Water quality is always a primary concern, so fuel, oil and other wastes should not be stored in the channel. Sudden high flows from rain storms may cause spills.

Fish, macro-invertebrates and other stream creatures rely heavily on the stream bottom to maintain healthy populations. The stream bottom provides food, spawning habitat, a place to protect eggs, nursery habitat and shelter from predators. It only makes sense that gravel mining can be harmful to these stream dwellers.

The smallest particles of sand and soil carried by a stream are called "fines." This is what makes a stream look muddy after a heavy rain. Normally, these fines settle as the water level in the stream falls after a rain and no harm comes from their presence. If we do something to cause an excessive amount of fines, then the water remains muddy and the bottom may become covered with this silt, causing many problems for fish and other aquatic life. We can prevent some of the risk by avoiding mining during the spawning season.

A common practice in gravel mining is to wash the gravel to remove these fines. Sand and gravel washing as well as gravel crushing and sorting should occur far enough away from the channel so that the warm, stagnant, silty wash water cannot enter the stream. This will protect water quality and prevent sedimentation (silting) of important stream bed habitats.

Using proper techniques and safeguards, it's possible to excavate sand and gravel without increasing erosion and with little or no damage to important habitats of aquatic plants and animals. If you have questions about proper ways to excavate sand and gravel from stream channels contact the Missouri Department of Conservation for guidance and a free brochure.

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