How to place rocks on a slope to stop erosion
Effective erosion control is an important technique for preventing water pollution and loss of soil. These controls are often used in natural areas, in an agricultural context or in the urban environment.
Today, climate change is increasing the likelihood of more intense rainfall and is also increasing the risk of runoff eroding part of the soil. The creation of barriers – with artificial vegetation or ‘conservation structures’ – established near streams or on steep slopes can slow down the flow of runoffs, help reduce erosion and improve water infiltration into the soil.
In this article, we’ll give out some practical steps on how to stop erosion on a steep hill, seaside and on agricultural settings while also emphasizing on how to place rocks on a slope to stop erosion.
Steps to controlling soil erosion
- Identify where to apply erosion controls: As earlier mentioned, erosion controls are usually used in natural areas, in an agricultural context or in the urban environment. In urban areas, they are often part of the stormwater management programs required by local administrations.
- Choose an appropriate barrier: Erosion controls often lead to the creation of a physical barrier, such as rocks and vegetables which are capable of absorbing part of the wind or water that is causing erosion. In fact, using river rock to prevent erosion offers the most effective barriers; this technique is often used in erosion control in slope projects.
On construction sites, these controls are often performed in addition to sediment controls, such as sedimentary basins and silt barriers.
- Prevent erosion: Ideally, the control of soil erosion begins with the prevention of the same, and some plants are perfect to promote this prevention. But when it is too late to prevent soil erosion, the only thing to do is correct an existing problem.
- Build containment barriers: These make it possible to tackle both the issues involved in the control of soil erosion i.e prevention on the one hand and correction of an existing problem on the other.
- Grow more trees: This seems to be the best way to prevent the soil from getting washed away. Trees, especially those with large and robust roots, can keep the soil intact. Growing a row of trees around a farm, if possible, can be a good idea to avoid the more mechanical methods of erosion. If you’re also wondering how to stop erosion around the house, this strategy can also work for your situation.
At a global level, many afforestation activities are often carried out (also known as reforestation), designed to preserve the soil.
A special variation of this phase occurs in the vegetation that grows along the banks, on the meeting point between any terrain and water. The intention is to prevent the land from slipping below the water level or to prevent the water from filtering into the ground and taking it away.
- Use debris: Some places like the coasts of rivers, streams, etc. can be mechanically blocked thanks to the deposit of some types of debris at the meeting point between land and water. A mechanical block can prevent water erosion of the soil. This type of barrier is commonly called “riprap”. On the other hand, instead, we can use strips of gabions formed by wire baskets created ad hoc and placed on the meeting point between land and water.
- Do not plow: The technique that farmers use most to control erosion is the “zero tillage” plowing method. This method, also known as conservative processing, consists of agriculture practiced through minimal processing. The plowing process, on the one hand, enriches the crop and on the other, moves the layers of the soil making it crumbly. And a layer of friable soil is more prone to erosion. This is why, as a measure to control erosion, agricultural practices that can produce a good harvest without the need for plowing are usually adopted.
- Consider using the girder: The girder is commonly used on sloping terrains. The ground floors get created by cutting off the ground according to the hilly profile. Along the contours of the land, walls called “bunds” are often erected. Agriculture is usually practiced in the areas delimited by these walls. The main effect of this type of control consists in the fact that both the flat land and the walls slow down considerably the outflow of rainwater.
- Enrich the soil: Erosion control is not just about preventing the soil from getting washed or wiped out. The methods to enrich any type of existing land consist in some practices of erosion control. One example is maintaining a fallow land, as most Asian farmers do. Here, after three or four successive seasons of cultivation, the land is usually left uncultivated for a season. During this period of time, the soil can regenerate some of its nutrients. Another method is to grow just a single crop before the main agricultural season in order to supply nutrients to the soil. Growing a legume crop can provide nitrogen to the soil as these crops can host Rhizobium, a beneficial bacteria that fixes nitrogen, in the roots of the roots. Another example is the Mucuna pruriens, a crop that supplies phosphorus to the soil.
- Use compost and fertilizer: Methods that provide for the addition of fertilizer, compost, etc. contribute to increasing the productivity of the soil and, at the same time, allow to keep erosion under control.
Use of barriers to reduce runoff from rain
How do you prevent soil runoff on a slope? There are several ways to reduce the flow of runoff water caused by heavy rains. Some of the techniques are:
- Partial barriers made by man (for example, fall structures and water retention dams) placed in streams and/or steep slopes to reduce the average water velocity.
- Stone barriers and/or with vegetation placed or planted across slopes to reduce the speed of runoff in the open field.
- Use of ditches: These are shallow, wide and vegetated channels designed to store and/or transport runoff and eliminate contaminants. They can be strategically designed to promote infiltration. In some cases, mulches on steep slopes tend to collect soil and organic matter and begin to form sewer-like structures.
Ideally, these barriers would channel excess water to containment ponds or infiltration zones where water can seep into the ground to recharge groundwater. If executed well, these relatively simple methods can be carefully developed in a water management system that can address both the problems of excess and water scarcity.
Disadvantages of using barriers to reduce runoff from rain
- It can be expensive, depending on the design and materials. Labor costs for the installation and maintenance of structures for runoff fall are a costly solution to the problem of channel erosion. However, in unstable soils, they may be the only solution.
- Due to high initial costs, expert guidance is strongly recommended to reduce the likelihood of failures that could result in additional costs.
- They can not avoid and/or stop extreme floods.
To stop water currents:
- Place tree branches along the stream and secure firmly with vertical poles. This will create a partial dam.
- Align the area under the dam with rocks to create a buffer basin. Now the water will fall from one to two meters in the lower basin, reducing its speed.
- Repeat the procedure periodically throughout the runoff area. You’ll need several of these fall structures along the runoff area as it passes through or near the coffee farm.
For areas with a slope greater than 30%:
- Build barriers with stones: When gullies have already formed in the soil as a result of heavy downpours, additional erosion can be effectively reduced with stone barriers, since these will absorb the impact of falling water and reduce the speed of runoff flow.
- Establish living barriers: Grassy vegetation barriers such as limoncello (lemon tea) on steep slopes also help to slow down the flow of water and reduce erosion and the likelihood of flooding. These barriers also help increase infiltration and reduce runoff from rain.
Rocks are important barriers you should consider if you ever want to find a lasting solution to erosion in whatever setting and we have emphasized this enough in this article.
If you’re looking for techniques to carry out, then those mentioned in this article will really help you towards achieving your goal. Don’t forget to let us know the end results.
Also, kindly share your experiences about other strategies which worked for you in stopping soil runoffs.