By: Emily Newton
New construction can harm the local ecosystem if erosion control isn’t prioritized.
Erosion can pose a serious risk to local environmental health — clogging waterways and making areas more prone to flooding. Without the proper controls, utility projects can sometimes make local erosion significantly worse. Using the proper erosion control techniques can help ensure utility projects have a minimal environmental impact.
The Importance of Erosion Control for Utility Workers
The installation or repair of utility equipment can generate large amounts of loose dust and dirt. Preventing erosion on utility project sites helps protect area water quality, improve local soil quality, and generally minimize the environmental disruption large construction projects can have.
At the same time, increased development worldwide has created many impervious surfaces like roofs, roads, pavement, and compacted ground that can conduct greater amounts of runoff after rain.
This runoff increases the local risk of flooding and can seriously impact the local environment. Runoff often carries that sediment from areas prone to erosion, as well as nutrients, hydrocarbons, and other pollutants that can lower the water quality of local streams, lakes, and wetlands.
Erosion also clears away topsoil. This could make the construction site and surrounding areas less fertile, reducing plant growth that helps to stall further erosion.
All of these factors mean erosion can have serious short- and long-term consequences for an area. Simple erosion control techniques, applied by themselves or in combination with other strategies, can help construction workers minimize erosion and a project’s environmental impact.
1. Vegetation Cover and Vegetation Establishment
Existing vegetation provides an effective barrier against erosion. Leaving as much vegetation in place as possible can reduce site erosion. On many sites, this may not be practical or possible, however. Clearing a staging ground, digging, and foot traffic will all destroy or remove existing vegetation.
Some of these factors can be mitigated. For example, limiting foot traffic to certain paths or areas can reduce the damage done to site vegetation. Digging, however, can be hard to minimize, and some room for project materials and equipment will always be necessary. A site may also have little to no vegetation to begin with.
As a result, it may sometimes be necessary to supplement vegetation during and after a construction project. Vegetation establishment solutions typically provide both short-term erosion control and the foundation for the longer-term growth of grasses and similar plants.
Vegetation establishment can provide similar benefits on sites where significant vegetation disruption can’t be avoided or where there was little vegetation to begin with.
Effective vegetation establishment is difficult, however. And despite significant research from organizations like state departments of transportation, it’s not unusual for new vegetation to fail to take hold after a project is complete. Erosion that occurred during the project may compound this problem.
In many cases, other short-term erosion control strategies may be necessary to lay the foundation for new plant growth after completing a project.
2. Mulching and Compost Blankets
Loose mulch or composted material can be spread over exposed dirt to reduce erosion. The compost blanket or mulch can absorb a large amount of water and provide a good environment for vegetation establishment. Despite being loose, both compost blankets and mulch are resistant to flooding and rain, and likely won’t be swept away.
Combination with other erosion control techniques can also help ensure mulch and composted materials aren’t washed away during periods of heavy rain.
3. Rolled Erosion Control and Sediment Control Products (RECPs/RESPs)
Rolled erosion or sediment control refers to fabric blankets or netting that help secure soil in place, preventing runoff. Like mulching and compost blankets, these blankets also absorb water and work to create an environment that encourages seed germination and vegetative growth.
This makes them a good complement to a vegetated cover erosion control strategy. Once the construction project is complete, these products can also be left behind to support new vegetation and help to minimize the lingering erosion that construction can cause.
In some cases, they may be more expensive and harder to source than mulch or compost but will likely be easier to secure and are less likely to be washed away by heavy rain or flooding.
The lifespan of erosion control products can vary considerably. Some vendors offer short-term solutions that last for a little more than a month and products that can last for years.
4. Silt Fences
Silt fences are temporary barriers that allow water flow while trapping silt and sediment.
These barriers can prevent sediment from being carried off-site by runoff but may need to be deconstructed and replaced with a more permanent solution after completing a project.
Because they will need to be deconstructed, they won’t provide any support for new site vegetation. If vegetation establishment is necessary for post-construction erosion control, silt fences may not be practical as the sole erosion control method for a project.
5. Rip Rap, Rubble, and Gravel
In some cases, it may also be practical to use rip rap — the permanent installation of large, irregularly shaped, and angular stones without mortar or other fillers — as an erosion control measure. The weight of the stones helps interrupt water flow and hold down sediment, preventing erosion due to factors like foot traffic and rain.
The approach is commonly used in slopes, channels, ditches, or other low-lying areas which may be eroded by wave action and will see minimal foot traffic during a construction project. Rip rap is easy to install and maintain and can help improve the water quality in an area by disrupting flow and encouraging settling.
Rip rap won’t always be an effective erosion control measure, however. The size of the stones needed often means it will take up a significant amount of space, much more than is used by lower-profile options like mulch or RECPs.
The approach is also typically more expensive than comparable methods, like the use of vegetation, and may also increase scour at the edges of where the stones are placed.
Smaller stones in the form of material like gravel can sometimes be effective as a rip rap alternative. However, the type of stone used can have a major impact on the method’s performance. Only gravel made of porous materials, like sandstone, will allow water to filter through. Non-porous gravel can impede site drainage.
Preventing Erosion on Utility Work and Construction Sites
These strategies are some of the most common ways in which construction crews work to manage erosion on project sites. Combining one or more of these strategies can help a team reduce soil loss and promote post-construction vegetation growth. This growth will reduce erosion in the area long after the crew has wrapped their work and moved on to the next site.
Emily Newton is a journalist with over four years of covering the environmental sector. As Editor-in-Chief of Revolutionized, she also covers the many ways technology is changing our world.