Drainage on any property is of paramount importance. Especially when it comes to hardscape projects like driveways. It’s often overlooked, but improper drainage can present a number of problems. Some will show quickly, while others could take years before you notice, by which point it will be too late. In this post, we’ll go over why drainage is important as well as different types of drainage systems for your property.
If not disposed of properly, water can cause damage, discoloration, and excess wear of all concrete and other paved surfaces. It also washes out and destabilizes base materials and gets into subgrade soil levels causing expansion and loss of load bearing capacity.
This causes cracks, lifting, base shifting, and similar damage, which requires complete demolition and replacement of any affected pavement. On unpaved surfaces, such as your lawn, it may cause sogginess and may wash soil away, destroying plants in the process. The worst damage, however, could be to foundation of the house itself.
If water finds a way to your foundation, which can happen if drainage is not designed and built by educated professionals, it may get damaged, causing an enormous problem that’s very costly to repair, if a repair is even possible.
With our team of engineers, we take drainage very seriously, and examine it on a case by case basis. Types of drainage used to make sure your property is free of water issues depends on many factors.
First off, we have to differentiate between draining paved versus unpaved surfaces. Excess water on unpaved surfaces is best dealt with a French drain. A French drain consists of a perforated pipe underground. A filtering layer is laid on top of the pipe so water can seep through the soil, into the filtering layer, and ultimately, through the perforations into the pipe. The pipe is solid in its bottom half and laid on a sloped trench, so it carries the water further along.
This type of drainage will protect your lawn from being soggy and will drain any pooling water. It is a must for retaining walls, which are not designed to withstand the tremendous additional pressures that a build-up of water will present.
The other type of drainage for the same use is a trench drain, which is a budget oriented solution with far less efficiency. If your goal is simply to get water away from a soggy area quickly and a bit cheaper, we can build a trench filled with drain rock and topped off with soil. However, be advised that these are not nearly as efficient nor reliable, and there is much less control of where the water goes.
For paved surfaces, we use a combination of channel drains and basin drains. These two are very similar in that they both collect water running freely on the paved surface, the only difference is in their shape and size. A box drain may measure around a foot by foot and be placed next to a curb, a retaining wall, or simply have the paved surface sloped toward it. A channel drain is used to cut off water flow over a bigger area, essentially protecting a vulnerable object, such as a garage at the bottom of a driveway sloped towards it. These two systems will effectively collect water that has nowhere else to go and that would otherwise be bound to pool and drench your fence, walls of your house, or foundation.
However, sometimes there is just too much water to dispose of safely. It will either make a huge stream on the city sidewalk, or make the lawn soggy. In those cases, the best solution is using a dry well. A dry well is an underground, perforated container that slowly bleeds excess water that got collected during a rainstorm, with an emitter at the top with an overflow in extreme cases.
In rare cases the final outlet spot gets too low underground because of property topography, a sump pump is needed to pump the water out to the final recipient.
Rainwater gets collected into roof gutters, and there are usually 4 major downspouts to carry all of that water to the ground. It is essential that this water is accounted for. If the downspout is over a grassy area, planter box, or other natural soil, it can potentially discharge the water there.
However, over paved areas, it's compulsory to route that downspout underground. If there is free flow of water from a downspout onto a paved area, it's certain to damage that area. At the very least, there will be stains and discoloration. Over time, concrete is bound to get worn out.
Once a concrete surface is worn out, the rest quickly follows and gets washed out. In the case of pavers, water flowing violently during a storm from a downspout will wash out the sand and possibly even the base rock, destabilizing the pavers.
Whichever system is installed, water is carried via PVC piping underground to the final outlet. That outlet may be of several types. The simplest one is simply a pipe near a water recipient, be it a lawn, or the vicinity of a street gutter. A more elegant solution is putting a pop-up emitter on the end of the pipe. A green pop up emitter is discreetly placed in a grassy area, and when there is water pressure, it pops up and releases water.
Don't make the mistake of forgetting about water because it may invalidate all of the work you have done. Let our engineers make sure you are protected from the potentially destructive effects that water has on buildings and hardscape.