Save Money with This Long-term Fix for Scour Problems

Scour poses a large threat to the stability of any structure that is partially or entirely underwater. It may develop slowly over time, or be brought on quickly by an intense rain event or seasonal flooding. In some cases, such as along a shoreline, scour can be very evident. In others, scour can go unnoticed for an extended period of time. Whether it is taking place around the footing of a bridge pier, along the base of a sheet pile wall, or along a tailrace on a dam, scour may not be evident until the structure begins to show signs above the water. At this point, the structure is beginning to fail and repairs must be done soon to avoid a total loss of integrity. Repairing scour and erosion issues that may be going unnoticed in any location is vital as it will save a lot of money in the long run, and extend the life of the structure.

Our experience in wetland habitat restoration began decades ago with the Upper Mississippi River Restoration Program (UMRR), the largest restoration program ever undertaken on a major waterway worldwide.  Since then, restoring marshes, wetlands, and highly sensitive ecosystems along inland and coastal waters nationwide has been a main initiative.

Lock and Dams, bridges, pipeline crossings, and barge terminals are all examples of water-based infrastructure. Ensuring that these structures maintain their integrity is essential to their continued operation, however water-based infrastructure presents an added challenge because a portion of the structure is underwater.

---Updated July 25, 2022, by Kimberly Walters---

Upgrading infrastructure in the United States of America has long been delayed and is now reaching a critical point. Replacing railroad bridges that are old or have exceeded their useful design life is just as important as any other element of our nation’s infrastructure. Bridges are a small component of an extensive railroad system. However, if taken out of service, a whole line could be shut down. Railroad companies would lose time, expenses would increase, and commodities would be delayed.

A story of Total Quality Management for an inland marine company.

The Bureau of Labor Statistics classifies a dredge operator as a person who removes sand, gravel, or other material in order to excavate and maintain navigable channels in waterways. In the industry, we call the dredge operator a leverman. This is a historical remnant of the days when the pilothouse, or lever room, was full of mechanical levers that controlled various parts of the dredge. The levers eventually gave way to computerized control systems...

Capping is an integral part of the remediation of a water body. As the benthic community generally lives on the bottom of a lake or river, these micro-organisms are a key piece of the ecological food chain. They are also very sensitive to contaminants, and any level of exposure can greatly reduce their population. Putting a cover, or cap, of clean material such as sand, engineered materials, or stone over the bottom of the waterway can provide the clean environment in which the benthic community can flourish while trace amounts of contaminants are left to safely decompose underneath.

Lock and dam and hydropower infrastructure face numerous unique challenges when it comes to improving the safety and reliability of existing dams. An important structural enhancement for dam stabilization projects is the installation of high-capacity post-tensioned anchors, which may supplement or replace existing anchors.

According to the Post-Tensioning Institute, post-tensioned rock and soil anchors provide a cost-efficient, high-performance solution for projects needing both temporary and permanent stabilization solutions.

Internships are an excellent way to gain hands-on experience and learn a little more about your field of study while working in a professional environment. At Nelosca, we value growth and development. Our COMPASS internship program strives to provide students with practical experience and useful knowledge to sharpen their skills in their chosen field.

All Systems Go

At Nelosca, we utilize hydrographic survey systems to measure progress on all of our dredging projects. These systems typically include a positioning system, such as RTK-GPS, and a multi-beam echo-sounder. The Real Time Kinematic, Global Positioning System, or RTK-GPS, is a precise satellite navigation tool, whereas an echo-sounder is a sonar device for measuring depth. Combining the two allows us to achieve very accurate measurements on the location of the river bottom. We take the data points created during these measurements and create a 3-dimensional model using Hypack® software. By running a survey before we dredge, and then one afterward, we can create two models and compare them to one another. The difference between the two models is the total volume of in-situ yardage that we have removed. Typically, we are paid by the in-situ volume of sediment (in cubic yards) that we remove so it is very important that these measurements are extremely accurate. Therefore, establishing quality control checks on the equipment before we survey is an extremely important step in achieving accurate measurements.