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Erosion and sedimentation control photos |
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Sediment carried by rainfall is one of the greatest potential environmental hazards of surface mining. Under the Surface Mining Law ALL surface water flowing off disturbed areas of the mine must be routed through sediment ponds. The ponds are designed to slow the flow of water so solid particles Enlarged Photo
Riprap
One of the most commonly used erosion control practices found on mine reclamation, highway construction, and throughout the construction industry is rock riprap. Here at this Southern Indiana reclaimed mine site the riprap is used in the emergency overflow of a permanent pond. If high rainfall occurs and more water flows into the pond than the drain can handle, the excess will flow safely over the riprap without causing erosion. This rock lining of the drainage channel slows the flowing water and prevents erosion of the soil under the rock.Enlarged Photo (100 KB file)
At this North Dakota mine reclamation a natural drainage swale is lined with a jute mat to prevent erosion until the grass becomes established. This is an erosion control practice that has been used successfully for many years on farms all across the country and is now commonly used on mine reclamation. This is a short-term erosion control practice that is a safeguard in areas prone to flash flooding or where it takes a long time to establish a dense grass cover. The matting is placed over the prepared seedbed and "stapled" to the ground to prevent it from washing down the slope. The mat holds the soil in place and provides cover for the new grass seedlings as they become established. Enlarged Photo (109 KB file)
At this reclaimed abandoned mine project water flows continuously down the channel to a stream at the bottom of the hill. Because the continuous flow of water and steep grade would damage a less resistant erosion control practice, a specialized mat was set in the graded channel and filled with concrete. When the concrete dried it formed a permanent channel for the water to flow. Although more expensive than a grass or riprap water way, this practice provides long-term erosion control for the fast moving water that drains off this reclaimed land. Enlarged Photo (114 KB file)
Large rock-lined drains have become one of the most commonly used methods of channeling water down steep hillsides at mine sites. Here on this Kentucky mine reclamation the operator has carefully set flat rock in the bottom and sides of the water channel. As one mine inspector said "if rock drains at all mines were constructed like these we would eliminate almost all chance of erosion occurring where collected water was drained from the reclamation." This rock-lined drain carries water down the steep hill and into a pond at the bottom. Its wide (7-8 feet) flat bottom can carry large flows of water and will continue to function many years after the reclamation bond has been released. Enlarged Photo (110 KB file)
During mining and reclamation at the Texas Utilities Big Brown Mine a two-and-a-half-mile section of Prairie Creek was mined through, restored, planted, and stabilized. The result is a natural stream configuration integrated into the surrounding wildlife habitat of trees, grasses and wetlands. Here a wetland was incorporated into the stream channel as part of the reclamation. Enlarged Photo (29 KB file)
Reclaimed stream reestablishes the original configuration
Erosion control structures
The mine site today
Before mining, Prairie Crees was similar to other East Texas creek beds that had eroded into narrow, steep sided channels. With the reclamation complete the stream follows its original pattern through the reclaimed landscape. The design of the reconstructed stream kept the disturbance to a minimum and uses only two erosion control structures.
Enlarged Photo (27 KB file)
To prevent soil erosion during periods of heavy rainfall and high stream flow two concrete structures were constructed. The concrete structures allow rapidly flowing water to drop in elevation without causing erosion of the creek bed. At the bottom of the structure concrete blocks were constructed to slow the flow of water and dissipate the force of the water. These structures provide a permanent solution to erosion control of the stream bed and provide a stable hydrologic environment that will remain for many years in the future.Enlarged Photo (29 KB file)
Today, after reclamation, the stream channel in this rural Texas landscape remains functional, aesthetically pleasing, and an important part of the natural environment. The successful mine reclamation has resulted in a productive environment that is difficult to distinguish from the surrounding unmined landscape.Enlarged Photo (29 KB file)
