Rain, and more specifically drainage maintenance, is key to well managed roadways. After the structures and pavement, drainage is the third most important asset making up a roadway system.
Drainage consists of everything from main storm drain trunk lines to ditches and all the way down to pavement under-drains. Preventive and proactive maintenance is critical to keep your roadway functioning for the long term. We will address some broad maintenance issues and strategies in this issue of Pillar Talk.
The storm drain system is designed to quickly drain the pavement surface and channel the water away from the roadway into the BMP (Best Management Practiceusually some type of basin or pond) and ultimately to a nearby creek or river. Basic maintenance is simple: keep large debris from clogging the inlets to preclude flooding events, and prevent or clean the small debris to prevent reducing the system capacity over time. Some strategies to maintain your drainage system include:
1. Debris Removal: While removing debris regularly may be called an “aesthetics” issue, in actuality this task is very important for drainage maintenance. More often than not, a broken Styrofoam cooler, old life vest, or even a large cardboard box will wash down the curb or barrier wall and cover the inlet grate/throat or even make its way down into the inlet and clog the drain lateral. This is easily remedied with routine debris removal operations. Be especially vigilant if your roadway is a tourist route leading to recreational water-sports areas.
2. Sweeping: Routine mechanical or vacuum sweeping will prevent accumulations of sand and sediment in the pipes. Theoretically, storm drains
are designed to be “self-cleaning,” however this only means the sediment makes its way into your BMP or nearby creek, necessitating costly cleanup at some later date. However, if the system has small debris wedged in the pipe or poor joints due to settlement or poor construction, the sediment will deposit in the pipe and cause a flooding condition. Routine sweeping will prevent these issues.
3. Drain Flushing/Vacuuming: If debris removal and sweeping are not performed, the only way to remove debris and compacted sediments is by manual drain cleaning or Vac-Truck flushing. This is an expensive way to remedy a flooded roadway. Typically this work is done on a reactive basis, once the roadway has flooded. Traffic control will likely consist of a shoulder or lane closure installed in an emergency situation at night, in a rainstorm, with traffic trying to pass at high speed with hydroplaning occurring.
As part of your Operations and Maintenance Team, we can provide a preventive maintenance plan to maintain your drainage assets in line with your contract Performance Requirements.