Stormwater Winterization for Renewable Energy Projects
By Dani Nygren, PE, Director, Wind; Aaron Mlynek, CPESC, CESSWI, QSD/P, National Construction Stormwater Leader; Joseph Ridley, Construction Stormwater Manager; J.B. Dixon, Construction Stormwater Permitting Manager
As we enter the winter season, many developers, contractors, and project managers are seeing the detrimental effects cold weather can have on their solar and wind energy projects during construction. The importance of stormwater winterization for multi-season projects cannot be overstated, which is why we sat down with our experts from the environmental and water resources team to discuss how they support developers in winterizing their wind and solar projects. This article will explore the insights gained by our leaders, who have over 60 years of combined industry experience and client support.
What is Stormwater Winterization?
Stormwater winterization is the process of preparing renewable, wind, or solar energy construction sites to withstand the harsh freeze-thaw conditions. This ensures projects remain stable, environmentally sound, economically viable, and in compliance with NPDES Construction Stormwater permit requirements. If construction activities continue through the winter months, expectations for erosion and sediment control Best Management Practices (BMPs) remain the same. We have extensive experience in this area, having worked on a variety of projects across different climates and conditions. Our proactive approach to winterization not only protects the project's integrity but also provides peace of mind to our clients.
What are the Consequences of Poor Winterization?
Failing to winterize properly can result in severe environmental and financial repercussions. J.B. Dixon, Construction Stormwater Permitting Manager, pointed out, “I've never come across a construction activity with more potential impact on water quality than utility-scale solar.” Poor winter conditions and little to no winterization can lead to soil erosion, sediment runoff, and damage to vegetation, potentially resulting in significant costs for clients, including delays, equipment damage, and regulatory penalties.
Joseph Ridley, Construction Stormwater Manager, shared two weather situations where winterization would have helped improve project timelines and service crews. First, from Texas, where a rare 17-inch rain/snow event caused significant soil movement and costly remediation efforts. Then, another situation in Iowa, where a rough winter made civil activities more difficult. Both situations illustrated the real-world implications of inadequate winter preparation.
When it comes to mitigating risks, Aaron Mlynek, National Construction Stormwater Leader, emphasized the importance of “getting things stabilized while you can,” suggesting that contractors focus on smaller areas and complete stabilization efforts before forecasted snowfall. Often: projects in cold climates encounter freeze/thaw cycles in late winter and early spring when mobilization and access become difficult to impossible. During this period significant failure of BMPs, accelerated erosion and sediment discharge can occur with little to no access of equipment and materials to mitigate the impacts. Being proactive with the approach can significantly reduce the risk of costly delays and environmental damage.
Winterization On Renewable Projects
Different Objectives, Different Practices
Winter Stabilization: This process involves stabilizing a site so a project can continue to be worked on throughout the season without causing major disruption to the site. It focuses on erosion control and minimizing disturbances through practices like dormant seeding, mulch blankets, and timely adjustments based on weather forecasts. There are also regulations that must be adhered to on a state-by-state basis, such as maintaining designated snow storage areas and access routes, clear buffers and perimeter controls, and cleaning equipment with compressed air rather than water. Following these precautions allows teams to take a phased approach, working on smaller, more manageable areas at a time and completing tasks before the weather changes.
Fortifying: It’s important to note that your construction site must remain NPDES-compliant throughout Winter, even if no construction is occurring. Fortifying is a comprehensive approach to ensure the site is secured before the winter shutdown, including thorough inspections, addressing weak points, and implementing a phased plan for an effective restart in the Spring, when access road restrictions inevitably occur within the site. Some measures taken include seeding all future vegetation areas to ensure germination, stabilizing all slopes with erosion control BMPs and temporary/permanent vegetation, and installing sediment barriers with vertical markers to help inspection during snowmelt conditions.
Stormwater Pollution Prevention Plans (SWPPP) and Phasing Plans
Effective Winterization is crucial for managing stormwater runoff and preventing erosion during winter months, necessitating a comprehensive Stormwater Pollution Prevention Plan (SWPPP). This plan outlines BMPs essential for protecting water quality and stabilizing construction sites. Early planning, ideally starting in October, is vital to avoid delays and stay in compliance with permit requirements.
A civil construction and stabilization phasing plan is also critical. This plan allows contractors to prioritize immediate stabilization needs and manage complex projects effectively, helping address potential issues before they escalate.
Solar and Wind Stabilization
Winterization practices differ significantly between project types, such as solar and wind. Solar projects require immediate stabilization post-installation due to limited access beneath the panels, making timely action essential to avoid costly remediation later. In contrast, wind projects, with more dispersed areas of disturbance, offer more flexibility in timing for stabilization efforts. Both efforts involve significant ground stabilization measures, access point maintenance, and effective planning in advance.
Unpredictable Winter Weather Patterns
Winters are becoming increasingly unpredictable, making preparation more important each year. We are experiencing everything from severe snowstorms in areas that typically receive little snowfall to harsh freeze-thaw cycles in places that are typically stable. In Minnesota, for instance, the construction landscape has shifted dramatically. In the early 2000s, it was tough for contractors to work past Thanksgiving without shutting down; now, with a warmer season, “nobody shuts down.” This trend reflects a broader adaptation to winter construction, despite the inherent challenges associated with it.
J.B. Dixon highlighted this unpredictability, stating, “Some of the worst impacts are evident in the fall or in late winter/early spring when it’s a high of 40° and low of 20°.” Sudden weather changes can lead to project delays, increased costs, and safety hazards, underscoring the necessity for robust winterization strategies.
To combat these risks, construction teams must implement effective planning, including a comprehensive Stormwater Pollution Prevention Plan (SWPPP) and a well-structured phasing plan. As Aaron Mlynek pointed out, “Every time [the weather] catches contractors off guard, it impacts their project, their client, and the environment,” highlighting the critical need for proactive site management in the face of unpredictability.
Planning for Multi-Season Projects
Winterizing multi-season wind and solar energy projects is a critical aspect of project management. We stress the importance of tailored strategies to address the unique challenges presented by winter conditions. Our team of experts is ready to guide clients through the stormwater winterization process, ensuring solar and wind projects remain on track and in compliance.
We encourage clients to consider the implications of winter construction on their projects. As Dani Nygren, Director, Wind, noted, “Often, when creating those project schedules, this isn’t something that’s top of mind for everyone.” With a dedicated partner, you can navigate the complexities of winterization confidently, safeguarding your investment and supporting project stability.
If you are preparing for a multi-season construction project, please reach out to our team. Our experience in stormwater winterization can help you avoid costly mistakes and achieve successful project outcomes, even in unpredictable climates.
