Drainage Issues at Your Property
How to Deal with Drainage Issues by Chuck Green
Tips for Dealing with Drainage Issues from CGreen Landscape Irrigation
Since we often get asked questions about drainage issues in the Dallas area, we decided to dedicate this blog to helping explain how drainage issues occur and how to deal with them. Upon reviewing this blog on drainage issues, we welcome your feedback through the Comments section below and always encourage you to share ideas of other topics to blog about each week. Let’s discuss drainage issues…
First, if there is water collecting or standing in an area for less than a day, it may not be drainage issues unless it is around your foundation. In this case, the water drainage could penetrate under the foundation and cause the soil to heave which has a negative effect on your foundation.
Water standing for more than a day is usually considered drainage issues. You do not want to attract mosquitoes and other undesirable pests, nor do you want the unsightly problems of the standing water from these drainage issues. There are two types of drainage issues and drainage solutions to them – surface or standing water and subsurface water.
Regarding subsurface drainage issues where the term french drain is often used, this is a drainage solution to stop the flow of water horizontally under the surface. When the property is sloped and there is water slowly seeping out and onto a sidewalk for example or on an area that is unsightly or not safe, that would be a good place for a subsurface drainage system as would a home with a crawl space under it. This subsurface drainage system is a great way to avoid drainage issues.
If the property has an irrigation system installed, or the rains have been substantial, then the first 8 – 15” of our soil is fairly compacted. When you have periods of dry spells the soil will shrink and that is when you see cracks. Imagine what the soil looks like below that first 8-15” of compacted soil. Some of the cracks in the ground could and do go several feet deep and reach horizontally for many yards. Therefore, if you have a pier and beam foundation where you have a crawl space under your home or structure, it is quite feasible to have water flowing into your crawl space from yards even hundreds of feet away. That is a situation where a subsurface drainage system would be utilized to help avoid drainage issues.
Picture a large sponge vertically in the ground outside of your foundation to collect and stop any subsurface water flowing where you do not want it. In this example, under your house. A trench is dug usually 2 – 4 feet away from the foundation and 8- 18” below the beam of the house to stop the water. We line the trench with a geotech cloth that allows the water to flow through it but does not allow the soil to flow or penetrate through it. A pipe is laid in the bottom with holes strategically placed to allow water to enter the pipe and still carry it away. We use SDR 35 PVC pipe – not that inexpensive flexible pipe that has holes all over it.
Then we will fill the trench with gravel to within 2” of the surface, fold the cloth over the gravel to create an envelope or sponge, then we put gravel on top of the drain. Now this is important! If the geotech cloth is not used, the soil will penetrate into the gravel and make the drain worthless thus allowing for drainage issues to occur.
Water runs downhill of course, so if the French drain or subsurface drainage system is too deep to run to a point of discharge by gravity, then a sump pump will be necessary. There are many different kinds and ways to install a sump pump and pit – that will be another article as this could this could turn the drainage issues blog into a book:)
The clay soils we have in the North East Texas region, when compacted, as areas that get a fair amount of foot traffic for example, it can take up to 6 hours for water to penetrate just one inch. Therefore, it is great to have clay soil around your foundation sloping away from the home which creates a positive situation avoiding drainage issues. It is not a good practice to have loose, sandy soil around the foundation – so be careful what you plant in your landscape – in order to plan for avoiding drainage issues.
Surface drainage and drains are fairly simple. There are two ways to solve these drainage issues. The best, if possible, is to grade the surface so the water will run off to the street or an area that allows it to keep going. Typically, you see in the newer areas of development, the areas between the homes are graded properly to the street or perhaps an alley, but before the home is built or turf is installed to stop any erosion, it will rain, wash the soil down and the nice grade is more like a bumpy road.
That is when we can decide to regrade the area to avoid drainage issues or we can install surface drainage. Picture the drain in your shower. Now picture that same concept but 10-12” or larger. We install a box in the low area and have a grate that allows water to penetrate into the box and into a solid pipe that flows out to a lower area – usually through the curb into the street. If it flows to a lower grassy area, we need to make sure there is some kind of rocks or concrete as to not allow weeds, grass to stop up the pipe and flow of water causing drainage issues.
One mistake we sometimes see when dealing with drainage issues is downspouts or surface catch basins installed on a french drain or pourous pipe. This is definitely not a good way of dealing with drainage issues. Two totally different applications and problems will be waiting for you if you do this.
We hope this blog on drainage issues was helpful. Thanks for visiting and keep smilin’ – Chuck Green.
Chuck Green is Founder and President of CGreen Landscape Irrigation in Dallas, Texas. Chuck is licensed in handling many areas of drainage issues, irrigation and landscaping in Texas and has led CGreen Landscape Irrigation since 1980. To connect with Chuck and learn more about how to deal with drainage issues, he can be found online at Facebook, Google+ and LinkedIn. To connect with CGreen Landscape Irrigation, CGreen can also be found on Facebook, Google+, Twitter and LinkedIn.