Top Five Sediment Control Methods

Sediment control is an important part of maintaining a site. If not implemented, these areas easily become eroded. Wash off from some areas can pollute nearby streams, lakes, and rivers. The following methods offer the best protection and control.

Inlet Protection

One popular type of control is an inlet protection. Drop inlets are secured either around, above, or below the sewage grate. These appliances are often made of non-woven geotextiles. Some are made of synthetic fiberboard or wood chunks. For the drops used below sewer grates, an overflow opening is built-in to the design.

Curb inlet protection apparatuses are often tubing covered in a geofiber fabric. Sometimes the PVC is wrapped in polypropylene material. These products are placed in front of curbside inlets, keeping out sediment, pollutants, and debris from entering storm drains. This protection device does have an overflow gap and filter built in to keep the street from becoming flooded during use.

Perimeter Control

If the construction site is larger than just small repairs along the road, a perimeter device is necessary. Perimeter controls are put in place as a temporary measure, just until permanent ground covers can be put in place. There are several different types of apparatuses used for this task.

Sediment control fences provide a barrier that slows the runoff. It also helps to keep all sediment inside the work site and limits the filtering of sediment out of the site.

In addition to fences, sidewalk barriers help to transport the sediment off-site. This is a temporary trap for runoff. These may be used in conjunction with storm drain inlet devices.

Sediment Traps

In addition to placing barriers around inlets and construction sites, sediment traps are often employed. Scientists usually use these traps to study the quantity of particulates in lakes, rivers, streams, and oceans. However, they can be used in any water system to trap some sediment and keep the runoff from getting into the ecosystem.

Concrete Washout

Making and washing concrete is a major contributor to contamination. A washout helps to contain the runoff. A berm works with mixers, trucks, and wheelbarrows. It allows the concrete to be poured directly in and used. The berm then allows the contaminated water to evaporate safely.

For those who need something that will filter liquid and recycle aggregate for several washouts, a concrete filter is a better option. While it won’t work as well with wheelbarrows, it is compatible with trucks and mixers. The filter pulls sediment from water and reduces the pH. This allows the water to discharge into vegetation when finished.

Check Dam

Check dams are a final way to control sediment at a worksite. This is a temporary structure placed over a drainage ditch, waterway, or swale. This structure interrupts water flow. It also flattens the channel gradient, slowing the flow of water. These structures have been known to collect sediment, however, they should not be the first choice for sediment control since they are not intended for this purpose.

Ohio Dam Safety Program Keeps Citizens Safe from Disaster

Photo Of The Hoover Dam - Garrett and Associates

The Ohio Department of Natural Resources (ODNR) has showed its commitment to dam safety by establishing the Ohio Dam Safety Program, which allows businesses and residents to continue to use the state’s many lakes and reservoirs for business or recreation without sacrificing the safety of those downstream. Dam and reservoir failures can lead to countless injuries and deaths, millions of dollars in damage, and displacement of citizens, so it’s important that dam safety be a priority in Ohio.

Why is Dam Safety Important?

While modern dams are hugely beneficial to Ohio communities, they also pose potential safety hazards. Over the last century, high-profile dam and reservoir failures have devastated communities across the U.S., killing hundreds of people and displacing even more. Dam failures can occur in the blink of an eye, so it’s important for dam operators, safety officials, and community members to be prepared for such a disaster in their own communities. One way to prevent this devastation is to identify signs of failure before disaster strikes, allowing for time to evacuate citizens and, if possible, make necessary repairs to the structure.

What Causes Dam Failure?

There are three main concerns when it comes to dam failure. The first, accounting for about one-third of all dam failures in the U.S., is called overtopping. Overtopping often occurs when the spillway has been poorly designed or has been blocked by debris, causing structural damage or allowing water to crest over the top of the dam. Foundation defects contribute to another 30 percent of dam failures. These dams are often poorly designed and experience problems related to settling, slope instability, and other preventable issues. Another cause of dam failure is piping, which occurs when water slowly seeps through pipes, spillways, foundations, and other sections of the dam, causing internal erosion that weakens the structure. Piping issues account for about 20 percent of all dam failures in the U.S.

About the Program

The Dam Safety Program was established by ODNR to keep Ohio’s citizens safe while allowing residents and businesses to continue to reap the benefits of the state’s many dams. The program holds dam owners accountable for maintaining the condition of the dam and eliminating risks to civilians.

The program operates on a five-year schedule, with every dam or levee undergoing a thorough inspection during each five-year period. The ODNR has also partnered with the U.S. Environmental Protection Agency and the Ohio Environmental Protection Agency to provide similar inspections of coal ash impoundments across the state. Thanks to FEMA funding, the state has also implemented an Emergency Action Plan to educate the public on emergency procedures for dam-related disasters. Additionally, the program seeks to modify safety and structural requirements for construction of new dams and reservoirs, including offering discounted fees for dam owners in compliance with the new rules.

For more information about the ODNR Dam Safety Program, visit the ODNR Division of Water Resources online.

Photo Credit: Stephen Kruso