Wadis are becoming increasingly popular as a sustainable rainwater management solution. These natural drainage systems not only have ecological benefits, but can also help prevent flooding and restore groundwater. In this article, we take a closer look at what a wadi is, how to construct it, and what supplies you need to do so.
What is a wadi?
A wadi is a dry riverbed specifically designed for the conduction and absorption of rainwater. The concept is based on traditional water management practices, where excess rainwater is diverted to specially designated areas. Instead of simply draining the water, a wadi allows the water to infiltrate into the soil, replenishing groundwater. How to construct a wadi? Constructing a wadi requires careful planning and execution. Here are the basic steps for constructing a wadi:
Site analysis
Choose a suitable location for the wadi, taking into account the natural terrain and the flow of rainwater. If you place the wadi in your garden, it is wise to place it at least 3 metres away from your house.
Design
The wadi is preferably located at the deepest point of the garden, the place where the water stays the longest after a heavy rainfall. A wadi in the back garden is about 1.5 metres by 1.5 metres with a minimum depth of 30 cm. Permeable soil Use suitable materials such as gravel to create a permeable soil, allowing rainwater to penetrate the soil easily.
Vegetation
Plant the wadi with native vegetation. These plants not only help absorb water, but also contribute to the stability of the wadi.
If you prefer insects in your garden, turn your wadi into an infiltration case. An infiltration case is narrower and deeper and only has gravel at the top. If you want to make sure no insects come off your gravel case, lay gravel grids with a membrane on top of the gravel case. On top of the gravel mats, lay a layer of gravel or grit of your choice. This will ensure that water can drain easily and insects such as mosquitoes cannot reach it.
When constructing a wadi, some essential products and materials are crucial to ensure effective rainwater harvesting and infiltration. Here are some of the products you will need: Geotextile Place geotextile as a protective layer at the bottom of the wadi. This prevents the soil from mixing with input materials, such as gravel, and improves water permeability.
Gravel Choose water-permeable materials such as gravel to fill the bottom of the wadi. These products are available on Amagard.com and help create a porous surface, allowing rainwater to infiltrate easily.
Gravel or grass mats
Consider using mats to increase the stability of the wadi and or gravel grids with a membrane to repel insects.
Conclusion
A wadi provides a sustainable solution for stormwater management by capturing, conducting and infiltrating excess water into the soil. Constructing a wadi requires careful planning, including site analysis, detailed design, excavation, creation of permeable soil, planting with native vegetation and regular maintenance. By following these steps, you not only contribute to flood prevention, but also promote the preservation of local ecology and groundwater recharge. Thus, constructing a wadi is not only a practical but also an eco-friendly water management choice.
