Drainage in the Lowcountry
It seems as if every time it rains, no matter how much, somewhere in Charleston is flooding. Flooding or standing water is a common problem within the landscape in the Lowcountry. Our beautiful city has minimal hills and change in elevation, so when it rains the water will stand until the ground allows the water to soak within. Flooding in your landscape can be caused from roof water on your house and dumping water in the landscape beds or out into a low spot on your lawn. Homes that don’t have gutters tend to get water under their homes or sitting against the foundation. This can cause the foundation to become poor and eventually crack or sink. Flooding also occurs when yards have never been graded properly so the water will find its way to the lowest spot and sit until it perks into the soil and evaporates. Homes that are built close to a creek or waterway may have trouble with water backing into their yard with an extremely high tide or king tide. This results in flooding as well. Throughout the rainy season there are times that the water table is so high that the ground will only accept so much water which results in more time of standing water. Standing water in the landscape or around the home is not only unattractive if not set up correctly, but it can also be a magnet for mosquito breeding, can create fungus within a lawn or on a plant, can produce root rot within your plants, cause your floors to warp, break down a foundation, create ruts within a gravel drive, and even cause rot on the lower portion of your home.
Flooding and standing water can be a difficult constraint to overcome, but it can be mitigated. Our company has started to become experts on drainage issues as Charleston seems to be getting more and more rain as the years go on. We specialize in gravity fed drainage systems and dry well/sump pump systems to move water off of your landscape and away from your house. We can pinpoint signs of flooding and will also use a grading rod and transit to locate low spots. We install our systems to industry standards and check with local regulations before installing. Our company can also follow drainage plans for new construction or complete landscape renovations.
The first step in proper drainage before even installing a drainage system is making sure the soil around your house is higher than the rest of your yard. When water hits the soil it will flow away from the house if graded correctly. There are times when this is not possible and when French drains become a huge part in getting the water off of the foundation and away from the house. The next step is taking inventory of all of the low spots in your landscape beds and throughout the yard. The best way to do this is in a heavy rain event. Once you notice these, flag them so when they dry you still know where they are. This is not only helpful for you as the homeowner, but also showing the contractor you decide to hire to fix these issues. Once you know this, it is time to come up with a plan.
Carolina Landscape installs simple catch basin systems and French drain systems to advanced systems with a dry well and multiple drainage types together including submersible pump systems. All of this depends on what type of drainage issues you are having. Our goal is to keep your site as dry as possible for not only you, but for your plants and turf. We suggest (5) different ways to correct improper drainage.
French Drain Systems
We usually will install a French drain if you are having issues with water getting under your house. Most of the time that happens if gutters aren’t present or the grade against the house is lower than the rest of the landscape. Our French drain systems consist of a 12”+ trench lined with fabric and filled with a “57” size gravel and a 4” perforated PVC pipe. The French drain will be installed along the foundation around the house and will either exit into a dry well and pumped to the street, a nearby city catch basin, or a nearby creek or drainage ditch. Our French drain systems are gravity fed, so the pipe will always have pitch on it towards the lowest spot we find or create. We always use hard PVC pipe and highly suggest against using corrugated pipe for any drainage systems as they tend to get crushed or fill with tree roots over time. Once the system is in we suggest installing gravel to the top of the landscape to help with filtration and to reduce any muddy splashing onto the foundation from the roof water.
Catch Basin Collection Drainage Systems
Our company is a big promoter of using catch basins to collect and disperse water when installing a system. We often install catch basins under each downspout on your gutter system and we also install them in low spots throughout the yard to collect any standing water. Installing these under your downspouts will never give your roof water a chance go into your landscape. Doing this ensures no extra erosion within your beds or lawn and no chance of your roof water collecting in a low spot within your property. If we have enough gravity we will use (1) one or several catch basins as the exit for your drainage system as well. We like putting this close to the street as it pushes water off of your property and into the city storm water drains. If gravity is an issue then we will collect all water into a “holding area” or dry well and then pump it off site.
Rain Garden Drainage System
There are times when the only choice you have is to pump the water away from the house or to actually collect it in an area and use the water as a focal point in your landscape. This is where a rain garden can become a really enjoyable area on your property. We can collect all roof water and any low or wet spots within your landscape, filter it through a French drain, and then push it into a large existing low spot or we can create one. We line the hole in the ground with fabric and then install a deep gravel base, another layer of fabric, and 8-12” of a garden mix soil that drains well. We then will plant water loving plants such as Common Rush, Papyrus, Iris, Joe Pye weed, etc. Once the plants are in, we will then install a decorative rock such as a mix of .50” , 2-3” and 6-8” decorative stone. When it rains your rain garden will fill up and you can enjoy a temporary pond filled with lush plants for days and even weeks depending on how much it rains.
Grading for Drainage
If your home is new construction or if we are doing a complete landscape renovation then a drainage system may not be needed if we can grade your property to shed its water to the street(s) or into a nearby creek or drainage ditch. We would bring in a sandy fill dirt and topsoil mix to grade away from the house, but having the sandy fill will also let water perk into the ground. This is the easiest and most cost effective way in the beginning to get water off of your property.
Tidal water can become an issue for some of you living on waterways here in Charleston. These tides can not only soak your yard and not allow you to enjoy them during high tides and high rains, but it can also erode and pull your soil, sod, plants, and mulch back into the water. One way to help with that is building a berm in along your property and even down the sides depending on how far the water comes in. This will not allow tidal water to come onto your property. However, this can also not allow rain water to exit your property. In some cases, we have had to install a drainage system to collect the rainwater that could not exit the property and then pump it into the waterway. We have also installed pipes through the berm that allows water to flow off of the property, but not back onto the property. Before doing this work, we will ask for permission from the town you live in and have the critical buffer line marked as to not encroach onto the marsh.
Rain and water in general is something we love and need, but something that can really ruin a nice landscape, property, or even important parts of your home. Understanding how water moves and where it goes is something we really understand and like working with. We want to keep your landscapes, homes, and properties as dry as possible so you can enjoy them even when mother nature doesn’t want to play nice. Drainage is a key component to having a landscape that looks nice, is well- functioning, and that you can enjoy.