Why Is Drainage Necessary?
Sources of Water
To properly implement a drainage design, you have to consider the water sources that could create problems on a jobsite. There are two primary sources of water:
- Surface water
- Subsurface water
Surface water is the type of water most considered to be problematic on jobsites. This type of water includes standing and running water that is visible on the ground’s surface. Often it isn’t present when work starts, unless it has recently rained. Most surface water collects after it rains and will remain on the jobsite as standing water until it can be absorbed into the soil.
Urban areas tend to have more problems with surface water as there are more non-absorbent areas like concrete, roofs, and driveways. These surfaces tend to have standing water issues for longer periods of time and rely on evaporation more than absorption. Typically, water will pool in areas that are depressed or lower than the surrounding areas.
Encountering subsurface water is a cause for concern. This type of water can result in unexpected issues and can be difficult to see at first glance, because it is found under the visible surface. It requires more research and consideration to ensure it doesn’t turn into a problem.
The cause of most subsurface water is infiltration, which can come from aquifers or surrounding areas. Subsurface water poses a different problem than surface water; it can make soil excessively wet, which in turn makes it difficult to work in those areas.
Leading Indicators of Drainage Problems
Surface obstructions can cause the following problems and should be considered when creating a drainage design.
- Property needs to be correctly graded to prevent improper drainage.
- Tree roots and shrubbery root systems can impede water flow on the surface.
- Objects in the area, like timber, bricks, and equipment, can obstruct water flow, which can be a significant problem if it redirects the water into a place where it can pool.
- Artificial surfaces, like sidewalks, can obstruct, inhibit, or retain water in locations where work needs to be done.
Subsurface obstructions bring a different set of issues that warrant consideration in the planning and design phases.
- Poor soil conditions that are common in a particular area.
- Irrigation systems that are broken or improperly installed causing problems in subsurface water for surrounding areas.
- Surrounding properties that have other water flow issues that affect the jobsite.
- Tree roots and shrubbery root systems that also affect subsurface water flow.
If you notice a problem with a jobsite, determine the type of problem and the degree of the issue.
Degrees of Drainage Problems
The first step is to identify the source of the problem. Drainage issues generally fall into three categories:
- Problems that are inconvenient – Aggravating issues are typically not serious but can cause a problem. One of the most common forms of a nuisance problem is standing water that doesn’t disappear. Standing water can cause a lot of other issues, like mosquitos, root rot, and an inability to progress with a project.
- Problems that could cause damage – Evidence of some structural damage to outside buildings and structures.
- Problems that cause damage – These can combine elements of the other two degrees of drainage issues but include water getting into the structures in the area, and other damage. Learn more about how to troubleshoot and find a solution for your drainage issues.