Photo Credit: Karl Jansen
Revetments, riprap, large rocks… they all mean the same thing in this case. These rocks placed along the side of a river are formally known as revetments. Their purpose is to absorb energy from the water rushing by. By absorbing the passing water’s energy, they do their job to prevent erosion of the river bank. Riprap is usually the term used for rocks placed where runoff from a large storm might cause environmental impact problems like erosion.
Photo Credit: Alex Mead
Seen here is a smoke stack on a building in downtown Grand Rapids, MI. This shot was taken using an extended exposure, which makes the steam rising from the smoke stacks appear to be flowing in an odd manner. Although it is hard to tell from this angle the plume is a looping plume.
Photo Credit: Karl Jansen
Pictured here is a fish ladder located at the Hiram M. Chittenden Locks (a.k.a. Ballard Locks) in Seattle, WA. A fish ladder is simply a structure that allows migratory fish to swim upstream or around a barrier placed in the water by humans. In this case, the structures were a dam and some locks. The need for fish ladders was recognized after the placement of barriers in aquatic ecosystems had negative effects on fish populations.
Photo Credit: Alex Mead
Seen here are six screen units at an interceptor drain in Detroit, Michigan. These screens are used to clear debris from the water flowing through the drain in order to protect the pumps later on in the drain. The screens work by continuous rotating in a conveyer like motion to ensure that clean screen is always exposed to the flow. This continuous rotation ensures that the screens will never be blocked off plugging the flow of water which would cause damage to the screens.
Photo Credit: Alex Mead
The orange and black floating objects are containment booms used to contain potential oil spills into the Rogue River in Michigan. Containment booms are used stop an oil slick from contacting the shore as well as concentrating the oil slick to one place. By concentrating the oil it becomes possible to use skimmers and vacuums to collect the oil and dispose of it properly.
Photo Credit: Karl Jansen
This photo shows a silt fence in the process of being installed around the perimeter of a construction site. The purpose of a silt fence is to contain the fine silty material that is often agitated during construction activities and keep it from washing away. By keeping the silty material on site it effectively protects adjacent storm sewers and surface waters from contamination. A silt fence is composed of a synthetic fabric and secured in place by wooden stakes. This is a common method of erosion control used on a variety of projects.
Photo Credit: Nathan Shoemaker
Pictured above is a coal ash impoundment pond. Coal ash, a result from the combustion of coal in power-plants, is typically impounded in such ponds because the ash can be mixed with water into a slurry and pumped from the power-plant to the pond for extremely convenient handling. When deposited in the pond the ash will settle to the bottom and the water will be removed from the top and treated. Coal ash, classified as fly ash, bottom ash or boiler slag, depending on what part of the process the ash comes from is frequently disposed of in impoundment ponds. Exact disposal methods, however, are ultimately dependent on the state environmental code.
Photo Credit: Alex Mead
This is a fish ladder. It is used in conjunction with dams and weirs to allow migratory fish to pass around the main falls of the dam. It consists of small steps of waterfalls, one right after each other, so fish can make the jump from level to level getting up around the dam to continue their swim upstream. Without fish ladders many migratory fish couldn’t go up stream for spawning and the fish population would undoubtedly suffer.