Most of us know the forces of nature that cause erosion. Water, wind, and ice come to mind. Erosion is the wearing away of the Earth’s surface. It can happen slowly, over time or more rapidly, in the face of catastrophic storms. After watching Ian, Florida’s latest category 4 hurricane, there is little room to doubt the power of nature.
What about the power of humans?
How do we, as humans, contribute to soil erosion? The list is long. Human activities range from the more obvious such as deforestation, a lack of land management, mining, to agricultural activities. But the list does not stop there. Wherever humans start altering the landscape, soil erosion can happen. Think about the construction of buildings along a hillside, the construction of roadways that necessarily cut into the soil and human activities that accelerate climate change.
The simple act of disturbing the soil to plant seeds can cause some erosion. That soil disturbance is magnified with the use of heavy equipment, tilling and at times compacting the soil. Plowing, cultivating, and mowing all take their toll. Often, the way vegetation is removed has a direct impact on soil erosion. Crops that are taken from the fields, leaving them empty, with the soil exposed are subject to the greatest erosion.
Bad or misguided land management can cause land degradation, as in the case of deforestation. However, even well-meaning land managers who attempt to weight the benefits of cattle grazing on public lands against the possible land degradation, compacting of the soil, and waste contamination of waterways, often make the news. Even in Marin County, the issues of proper land management can turn litigious.
Deforestation, whether to make room for grazing cattle and growing more crops, or to make room for more housing, is continuing worldwide and especially in the Amazon Rainforest. This is particularly alarming because of the age and acreage covered by mature trees and other foliage there. The rainforest takes up approximately 2.72 million square miles and as burning and clearcutting continue, the area is at risk of desertification. In other words, what was once a rainforest can be transformed, by human interaction, to a desert. Deforestation also decreases the soil’s fertility.
This will be devastating, not only to the indigenous peoples who live there, and to biodiversity but to the world as a whole. The lack of trees and their root system opens the soil to rapid degradation and erosion. Brazil has also pushed the idea of expanding mining and large commercial farming efforts.
When it comes to soil sealing and mining activities, the indirect impacts such as heavy metal pollution that seeps into the soil and then into the water supply through erosion, can be devastating. Strip mining and mountain top blasting can take decades to repair and is still going on in parts of the US and the world. According to Appalachian Voices, “Since the 1970s, the coal industry has blown up more than 500 of the oldest, most biologically rich mountains in America and destroyed more than 2,000 miles of headwater streams.”
Devastating fires in the Western states, where drought is evident, leave entire swathes of land exposed to erosion. Many of these fires have been traced to human inactivity. Old and weakened power lines, not properly maintained sparked and ignited nearby trees and brush. Fire management is now being viewed through a new lens. The forestry department is looking favorably at controlled burns, like those the indigenous peoples practiced. The difficulty is that human activity has pushed housing deep into areas surrounded by forests. This makes maintaining a safe space around dwelling in these areas almost impossible.
Watering Gardens and Lawns:
Odd as it sounds, watering your garden or lawn can cause erosion. Set aside the longer list of Mother Nature induced events and land management issues. This is an area where you can make a direct difference. If you live in Northern California, where the drought is ongoing, you’ll want to factor in your landscaping and water limitations. Some residents are turning to simplified ground covering and the strategic use of native, drought resistant plants.
This type of planting is also a safeguard against fire, along with keeping plants a proper distance from the building itself.
Your choice of plants and erosion mitigation will vary depending on how level your lot is. On a relatively flat lot, you’ll also want to monitor your irrigation spigots, if you have them, to test for water pressure. You don’t want the water pressure to be so strong that it dislodges soil where the water lands. You can keep this concept in mind if you water with a garden hose, too. You want the water to be absorbed into the soil, not pushing the soil around with it.
If you live on a sloped lot, keeping the soil in place is even more crucial. As the drought wears on, some plants are dying out, leaving the soil exposed. Irrigation systems don’t always reach into the steeply sloped hillsides. Planting and hand watering species of native plants that are designed to hold the soil are your best option.
If you have an irrigation system that waters the vegetation on your hillside, remember to check your irrigation heads just as you would on a flat lot. Be sure the water is being released at the right pressure. Otherwise, it will simply roll down the hillside, taking soil with it.
Stabilizing retaining walls, shoring up hillsides and mitigating erosion are crucial steps in keeping your home and your property in good shape. The effects of erosion can be subtle until they cause real damage. In Sausalito in 2019 and in Fairfax in 2022, houses slid down hillsides, the result of unchecked erosion.
In the end, what matters most is how to prevent erosion, no matter what the cause. Mitigation measures continue to improve so if you haven’t looked into them in a while, you might be surprised at the choices you have today.
If you have concerns about erosion in general or how it could be affecting your property, call and talk to one of our professionals today. Erosion control is our business.