The Planning Advisory Service memo underscores the risks that industrial-scale solar can pose in creating significant stormwater and erosion management problems. These are not hypothetical risks, as every large-scale solar project installed in Virginia to date has created excessive stormwater runoff onto neighboring properties and into streams and watersheds, and creates erosion problems along waterways. The two main causes of these problems are the impermeable nature of solar panels themselves and the extreme grading of the land over a large area.

  • The site disturbance required for utility-scale solar facilities is significant due to the size of the facilities and the infrastructure needed to operate them. These projects require the submission of both stormwater (SWP) and erosion/sediment control (ESC) plans to comply with federal and state environmental regulations.
  • Depending on the site orientation and the panels to be used, significant grading may be required for panel placement, roads, and other support infrastructure. The plan review and submission processes are no different with these facilities than for any other land-disturbing activity. However, such large-scale grading project plans are more complex than those for other uses due primarily to the scale of utility solar. Additionally, the impervious nature of the panels themselves creates stormwater runoff that must be properly controlled, managed, and maintained.
  • Due to this complexity, it is recommended that an independent third party review all SWP and ESC plans in addition to the normal review procedures. Many review agencies (local, regional, or state) are under-resourced or not familiar with large-scale grading projects or appropriate and effective mitigation measures.  It is in a locality’s best interest to have the applicant’s engineering and site plans reviewed by a licensed third party prior to and in addition to the formal plan review process. Most localities have engineering firms on call that can perform such reviews on behalf of the jurisdiction prior to formal plan review submittal and approval. This extra step, typically paid for by the applicant, helps to ensure the proper design of these environmental protections.

planning for utility-scale solar energy facilities, pp 6–7

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