A Guide to the Different Types of Road Drainage Systems

22 September 2021
 Categories: Construction & Contractors, Blog

Are you responsible for civil works in your area? Whether you supervise a road construction or maintenance project or are responsible for hiring contractors for the job, etc., it's crucial to understand the basics of every civil work project. Generally, drainage is a vital aspect to think about when it comes to road construction and maintenance. That is because water can weaken the road surface, resulting in potholes over time. In addition, the subgrade soil or ground that supports the road surface may weaken with time if water is not drained correctly, reducing the road's bearing power.

All these issues pose significant risks to road users. That is why it is essential to have proper road drainage systems. Therefore, here is a quick guide on different types of road drainage systems.

Surface Drainage Systems

These are the most standard types of road drainage. This drainage system collects and disposes water within the roadway. It helps to keep the roadway free of any water that collects on the road surface, the pavement shoulders, embankment slopes, and even adjoining land. Surface drainage systems prevent water collecting on such surfaces from finding its way to the subgrade. Generally, the water is often led to nearby natural water sources like rivers or streams. Catch water drains or basins and side gutters are standard options to consider when it comes to surface road drainage.

Subsurface Drainage Systems

Subsurface drainage entails removing water beyond the pavement or road surface. When water accumulates in the subgrade soil to a certain extent, it can weaken the soil, affecting the road's bearing capacity over time. Generally, issues with subsurface drainage originate from the capillary rise, seepage flow, and a high water table. Therefore, to prevent subsurface drainage issues that may result from capillary action, an impermeable or bituminous layer can be added to the subgrade soil. On the other hand, seepage and water table issues can be controlled using subgrade drains, longitudinal drainpipes, trenches, or transverse drains. However, subsurface road drainage systems can be complex. Therefore, they tend to be costly.

Cross Drainage Systems

Cross drainage systems are essential where roads meet natural drainage channels like rivers and streams. Therefore, it becomes necessary to construct cross drainage systems to ensure effective water flow from the rivers, streams, etc., while preventing flooding on the road or pavement surfaces. Bridges, causeways, and culverts are standard cross-drainage structures to consider if the road crosses natural waterways.

For more information about civil works, contact local contractors.