The first thing that needs to be done when creating a floating wetland is to decide what kind of water source will be used. There are two types of sources which can be used for making a floating wetland: fresh or saltwater. Freshwater is usually better than sea water because it contains less dissolved solids and therefore has a lower pH level (pH stands for “phosphate” and it’s the measure of acidity). Saltwater is usually better than freshwater because it contains more dissolved solids and therefore has a higher pH level (pH stands for “phosphate” and it’s the measure of alkalinity).
In addition to choosing the type of water source, there are other factors which need to be considered. These include the size of the pond, its location and depth, whether it is going to have any rocks or other objects in it, and so forth.
If you want to create a floating wetland with fresh water then you need to choose a place where there are no large bodies of water nearby. If your pond is located near a river or lake then you might have problems with erosion from these bodies of water. In addition, fresh water is much more scarce than sea water and so it is usually better to try and conserve as much of it as you can.
If you want to create a floating wetland with sea water then you should try to place your pond as far away from the ocean as possible. The reason for this is that sea water tends to evaporate faster than fresh water.
Googling “pond depth” should give you a good idea of the depth to which your pond should be. If you want to create a shallow pond then there will obviously be less rock that you’ll need to obtain. If you want to create a pond that is fairly deep then you’ll need to find deeper water.
You’re probably going to have to do some digging in order to build your pond so it’s best if you wait until after a rainy season before doing any major construction. The more water you can remove from the area, the better.
You’ll also want to decide on a shape for your pond. A circular shape is probably the easiest to construct but you can really make it any shape that you want. It’s also probably a good idea to choose a small and manageable size. Building a pond that’s several acres in diameter is probably not the best idea for a first-time pond builder.
The next step in creating a floating island is finding rocks. The nice thing about building a rock garden is that you can use the rocks that you find on or near your property. If you don’t find enough rocks then you may have to obtain them from a quarry or some other location. The size of the rocks is also something that you’ll need to take into consideration.
You obviously won’t be able to use huge boulders as this would be far too heavy and would sink. You also don’t want the rocks to be so small that they’re not going to support anything. Somewhere in the middle is best.
If there are any big cliffs, boulders or stone outcroppings on your property then these are obviously good places to start looking. You may even be able to use parts of these as part of your island.
You’ll also need sand and dirt (topsoil). The sand and dirt will be used for leveling and shaping your island as well as making the land which the island will sit on. This may or may not be a problem depending on where you live. If you live in a city or town then you may have to obtain this from a different location such as a nearby quarry.
If you’ve chosen an area near the ocean then this is obviously going to be much easier to obtain. Just make sure that if you are going to get the sand and dirt from the ocean that you don’t deplete all of it. You don’t want to end up with nothing but rock.
You need to do some serious thinking before you begin your project because how you lay everything down is of great importance. You’ll want the base of your island to be fairly wide so it doesn’t fall over and sink.
Ideally, you’ll want to create a square or rectangular shape with the sand and dirt and then place your rocks on this foundation. It’s also a good idea to make your land very long and skinny instead of tall and skinny. In other words, you want your island to look like a rectangle instead of a tower. This will make it less likely to fall over.
Don’t worry about creating curved edges. You can make these easily with the rocks that you’ll place on the sand and dirt foundation. There are many different designs that you can do but keep in mind that the broader and more shallow the better.
The last thing that you’re going to need is water plants. These plants serve several purposes. The obvious purpose is to help keep your pond looking good. These plants also act as a natural barrier between the land and water.
Fish also like to hide out in the vegetation so you’ll definitely want to have it around.
The next thing that you’re going to need before bringing in any water is some kind of container for the water. A good size for your pond is going to be about 12 feet across. If you want it to be a constant depth of 6 feet then you’ll need a container that is 9 feet in diameter.
Now that you have everything that you need you can begin the process of bringing water to your island. Begin by digging a hole in the center of your island. This isn’t going to be your pond yet but just a hole.
As you’re digging make sure that the sides are sturdy. You don’t want the sides to cave in after you pour in the container of water. It’s best if you have someone helping you but it isn’t necessary provided that you take your time.
As the hole gets deeper you’re going to need to start making it wider as well so that it is wider than your container. Keep going until you are close enough to the edge that you can slowly pour the water in without it falling in before the hole is filled.
At this point, you’ll want to keep this hole filled with water. If there are any leaks then you can easily repair them before you move on to the next step.
The next thing that you’ll want to do is place your container of water in the hole you dug. You want to fill it all the way up and make sure that no sand or dirt is leaking into it. If there are any leaks then you need to patch them up before continuing.
You’re now ready to start placing your sand and dirt into the container of water but you need to be very careful doing this. The first thing you’re going to want to do is create a small dam around the container. This is going to prevent the water from leaking out as you place more sand and dirt into the container.
At this point, you’ll need to do some serious excavation. You need to carve out space for your land and you need to make sure that it is stable. Don’t forget that you’re going to have trees and other plants on your island so you’re also going to have to carve out a place for them as well.
The best way to do this is just take it slow. Dig out a small amount of soil then place some of the sand and dirt into the container. Keep doing this until you’re happy with how high the land is.
As the final step, you need to do one more thing. You need to surround the container with a low wall of soil. This is going to ensure that no water leaks out and ensures that the level of the water remains constant.
That’s it! You’ve now got yourself an island that never sinks and is always there when you need it.
Tips and Advice
You’re going to need to keep an eye on your new island. Over time, sediment is going to drop into the hole and land is going to erode. You might need to return every once in a while just to make sure that everything is in its proper place.
The bigger your island gets, the more work it’s going to be to maintain. If you want an island that is stable enough for buildings you’re going to have to put in a lot of time and work into it.
This method of island creation isn’t for everyone. It takes dedication and hard work. If you’re someone who would prefer to rest on their laurels then this probably isn’t the method for you.
Now that you’ve created your very own island, it’s up to you what you’re going to do with it. Maybe you’ll have an island filled with buildings or maybe you’ll just have trees and sand. It’s all up to you and the amount of work you’re willing to put into your new land formation.
Now that you know how to create a floating island, it’s up to you to put it into action. Remember, this isn’t an easy process so you’re going to have to work at it if you want your island to succeed. Now get to it!
Sources & references used in this article:
Macrophyte performance in floating treatment wetlands on a suburban stormwater pond: Implications for cold climate conditions by R Tharp, K Westhelle, S Hurley – Ecological Engineering, 2019 – Elsevier
Application of floating wetlands for enhanced for stormwater treatment: a review by T Headley, CC Tanner, AR Council – 2008 – researchgate.net
Use of Floating Wetlands to Treat Stormwater Runoff from Urban Catchments in Australia by C Walker, P Nichols, K Reeves, T Lucke… – … Conference on Urban …, 2014 – researchgate.net
Artificial floating islands: a technology for clean water and agricultural production in rural China by Z Li, Y Li, W Huang, L Sang – International Journal of …, 2013 – search.proquest.com