Ground Game: States leading the way in dripline erosion control

Soil erosion along the driplines of ground-mounted solar panels shows how human-made systems and natural environments interact in complex ways. Solving this problem requires a detailed understanding of factors like the site’s slope, gradients, rainfall patterns, and soil types. Smart land management practices not only control soil erosion but also help preserve the long-term value of the land.

The rapid growth of solar energy projects has highlighted the need for effective environmental management to protect the land, water, and ensure long-term stability. Dripline erosion can rapidly degrade the soil, threaten the stability of support pilings, and increase water runoff and sediment from the site that harms nearby water systems. To prevent these problems, solar farm designs need specific strategies that consider the unique environmental conditions of each site. A few U.S. states are leading the way to tackle this challenge by offering ideas for engineers, developers, and policymakers to work together to build environmentally and ecologically sustainable solar farms that last.

A few pioneering states 

About 20 percent of U.S. States have authored guidelines with detailed rules and resources to help solar farm sites manage soil erosion. For example, innovative solutions like the use of permeable materials and engineered ground covers are emphasized repeatedly. These solutions help to absorb runoff and stabilize the soil beneath solar arrays.

Specifically, Maryland takes a balanced approach by combining structural solutions, such as splash pads and stabilization mats, with strategies to encourage vegetation growth. Minnesota stands out with a runoff calculator, developed with the National Renewable Energy Laboratory (NREL), that helps engineers measure how much stormwater can be retained and where improvements are needed.

Georgia and North Carolina focus on areas where the land is steep. Georgia advises developers to identify erosion-prone spots and take extra precautions, while North Carolina emphasizes the importance of planting vegetation to slow down water flow and hold the soil together. These tailored approaches show how regional needs influence solutions, and highlight the importance of local policies in managing erosion effectively.

Tools and techniques for developers

Many tools and techniques are available to help solar developers control erosion. Hybrid-turf instant armor mats and aggregate splash pads are popular options that effectively protect the soil while allowing water to drain safely. These tools are especially useful in areas with heavy rain and/or steep slopes, where erosion risks are higher. 

Some states are also integrating environmental restoration into their erosion control guidance. For example, Illinois and South Carolina call out pollinator-friendly scorecards to combine erosion control with creating habitats for bees and other pollinators. Tools like Minnesota’s runoff calculator add another layer of precision, helping developers plan better and reduce risks before they become major problems. By maintaining soil health and stability, developers can avoid costly remediation efforts and enhance the overall return on investment (ROI) for solar projects. Incorporating these strategies can create a win-win scenario: protecting the environment while ensuring financial sustainability.

Economic and environmental benefits

Proper erosion management is not only about meeting regulatory requirements — it also has tangible economic and environmental benefits. By reducing sediment runoff, developers can lower maintenance costs associated with clogged drainage systems or degraded soils. Moreover, protecting the land’s integrity ensures that it remains productive for future uses, which is especially important in regions where solar farms coexist with agricultural activities. This dual-purpose approach — balancing energy production with land stewardship — will set a new standard for sustainable development.

Developers who invest in erosion control measures often find that the upfront costs are outweighed by long-term savings. Preventative measures such as vegetation establishment, buffer zones, and engineered drainage systems reduce the likelihood of expensive repairs and downtime. Additionally, enhanced land aesthetics and ecological value can attract more favorable community support, and even financial incentives from local governments aiming to promote sustainable practices.

How key factors lead to a sustainable future

Managing dripline erosion is more than just following regulations and guidance; it’s an essential part of creating solar farms that are both environmentally friendly and durable. As guidelines evolve and new tools become available to effectively combat erosion (such as the previously mentioned hybrid-turf instant armor mats), it’s crucial for developers, engineers, and policymakers to stay informed and adopt the best practices. Working together, these groups can ensure that solar farms minimize their environmental impact while contributing to clean energy goals. 

Addressing dripline erosion is critical to the success of solar energy projects. A few states are leading the way for us all. These efforts will not only solve immediate problems but also pave the way for a greener, more resilient future.

Tim Lancaster is Vice President Sales at GrassWorx, which designs and manufactures products that move water and dampen impact noise.

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