Managing Stormwater Runoff: Comparing Agriculture vs. Solar
Stormwater runoff can be a concern for neighbors of any commercial development. Runoff can significantly affect water quality and ecosystem health and lead to flooding in surrounding areas. Development of any kind can lead to disturbances in how water flows, especially when hardened surfaces like parking lots and roads are added or natural vegetation is removed. So, it is understandable that residents close to utility-scale solar sites may have questions about how a project will impact the water in their area. As more solar projects are developed in rural areas, residents typically surrounded by agriculture may actually see fewer impacts from stormwater runoff.
Stormwater runoff occurs when rainwater flows over impervious surfaces like parking lots or compacted farmland, carrying pollutants such as sediments, fertilizers, and debris into nearby waterways. This process disrupts natural hydrology, increasing the risk of flooding and contributing to harmful effects such as blue-green algae blooms in lakes and rivers. According to the EPA, agriculture is one of the largest contributors to polluting our waterways due to runoff from fields that use fertilizers and other chemicals (Nonpoint Source: Agriculture). Furthermore, when priming land for agricultural use, the natural swales - the shallow, vegetative depressions that slow and absorb water - are removed to make planting and harvesting crops easier. Without swales, runoff accelerates, washing away excessive amounts of natural nutrients like nitrogen and phosphorus into water bodies, fueling algal growth that can harm aquatic life and water quality.
While commercial development can also pose risks for runoff, large projects, such as solar farms, must comply with regulations and include proper stormwater management to mitigate these effects. In New York State, any commercial development disturbing one acre of land or more must adhere to the New York State Department of Environmental Conservation’s (NYSDEC) Stormwater Pollution Prevention Plan (SWPPP). These regulations ensure developers include measures like retention ponds or vegetative barriers to manage stormwater onsite, preventing sediment and pollutants from leaving the property and reducing the risk of flooding to surrounding areas. However, agriculture is notably exempt from having to follow SWPPP. This lack of oversight often results in unchecked runoff from farms, whereas these issues are addressed on solar development sites.
Utility-scale solar developments, like the upcoming 500 MW projects planned for Elba and Oakfield must meet NYSDEC's rigorous standards to protect local waterways. And not only will this land no longer contribute to the pollution that came from it as a farm, but the scale of this solar farm will require stormwater management infrastructure that can prevent pollution from surrounding farms. Scientists from Clean Wisconsin testified that a utility-scale project in Sheboygan County, Wisconsin, could reduce phosphorous runoff to the local watershed by 85-98% (Wisconsin Solar Farms Can Improve Water Quality).
For these reasons, as family-owned farms diversify their income by leasing their land to solar, rural areas may see a decrease in waterway pollution from agricultural runoff. As we mentioned in our previous newsletter, much of the corn grown in New York State goes to biofuel, which requires more land to create the same amount of energy as solar. By co-locating solar and agriculture, we are increasing the efficiency of energy production and protecting our waterways from pollutants.
This story is told by Shawn Grasby and written by Anna Castonguay.
