The MDE SWM Manual provides comprehensive guidance on stormwater management practices in Maryland, outlining principles, methods, and regulatory compliance for effective watershed protection and sustainable development.
1.1 Purpose of the Manual
The MDE SWM Manual serves as a primary resource for guiding stormwater management practices in Maryland, ensuring compliance with state regulations and promoting effective watershed protection. It provides clear guidelines for developing and implementing stormwater management plans, emphasizing environmental site design and best management practices to mitigate runoff impacts and enhance water quality. This manual is essential for professionals, developers, and regulatory agencies involved in stormwater management activities.
1.2 Structure and Appendices
The MDE SWM Manual is organized into sections and appendices for easy navigation. Appendix A details maintenance requirements, while Appendix B provides maps of SWM facilities in the Shop area. Appendix C includes an index of all facilities. Users can determine maintenance needs by identifying the SWM facility number, referencing these appendices, and ensuring compliance with MDE standards. This structure streamlines the process for users.
Key Definitions and Terminology
This section outlines essential definitions for understanding the MDE SWM Manual. Terms like Watershed Management Plan and Water Quality Volume (WQv) are defined to ensure clarity and consistency in stormwater management practices.
2.1 Watershed Management Plan
A Watershed Management Plan is an MDE-approved plan for counties or local municipalities, outlining strategies to protect and restore water resources. It ensures compliance with environmental standards, addressing stormwater runoff, pollution control, and habitat preservation. The plan is developed through watershed assessments, community engagement, and integration of best management practices to achieve sustainable water quality goals.
2.2 Water Quality Volume (WQv)
Water Quality Volume (WQv) is the volume needed to capture and treat 90% of the average annual runoff at a development site. It ensures effective stormwater management by reducing pollutants and sediments in runoff. Calculated using methods specified in the Maryland Stormwater Design Manual, WQv is essential for maintaining water quality and protecting receiving waters from pollution.
The Maryland Stormwater Design Manual
The Maryland Stormwater Design Manual, published in 2000 and revised in 2009, serves as the official guide for stormwater management principles, methods, and practices in Maryland.
3.1 Overview and Revisions
The Maryland Stormwater Design Manual, originally published in 2000, provides detailed guidance on stormwater management practices. It was revised in 2009 to incorporate updated methodologies and compliance standards, ensuring alignment with environmental regulations and advancing sustainable stormwater solutions across Maryland.
3.2 Role in SWM
The Maryland Stormwater Design Manual serves as the primary guide for stormwater management, providing standardized methods and practices to ensure compliance with environmental regulations. It plays a critical role in promoting sustainable stormwater solutions by offering detailed design criteria and best management practices for effective watershed protection and water quality improvement across Maryland.
Regulatory Framework
The regulatory framework for SWM in Maryland is established through the Stormwater Management Act of 2007 and COMAR 26.17.02, setting standards and compliance requirements for effective stormwater management.
4.1 Stormwater Management Act of 2007
The Stormwater Management Act of 2007 mandates statewide standards for stormwater management in Maryland, requiring the use of Environmental Site Design (ESD) practices to minimize runoff impacts. It ensures that both residential and commercial developments implement effective stormwater control measures, promoting water quality protection and sustainable land use practices across the state.
4.2 COMAR 26.17.02 Regulations
COMAR 26.17.02 outlines specific stormwater management regulations in Maryland, detailing design criteria, permit requirements, and enforcement measures. These regulations align with state environmental policies, ensuring compliance with water quality standards and proper implementation of stormwater management practices. They provide a framework for developers and municipalities to adhere to, promoting sustainable stormwater solutions across the state.
Environmental Site Design (ESD)
Environmental Site Design (ESD) emphasizes nonstructural stormwater management techniques, prioritizing natural hydrologic processes to minimize runoff and protect water quality through better site planning and design practices.
5.1 Principles and Practices
Environmental Site Design (ESD) principles focus on maintaining natural hydrologic processes to minimize runoff and protect water quality. Key practices include preserving natural vegetation, reducing impervious surfaces, and implementing techniques like rain gardens, bioswales, and permeable pavements. These strategies not only enhance water quality but also reduce pollution, aligning with Maryland’s stormwater regulations and promoting sustainable development.
5.2 Phosphorus Removal Rates
Environmental Site Design (ESD) practices are designed to achieve specific phosphorus removal rates, ensuring compliance with Maryland’s water quality goals. Techniques like rain gardens and bioswales can effectively reduce phosphorus loads by filtering runoff. The MDE SWM Manual provides detailed guidance on selecting and designing BMPs to meet these targets, aligning with COMAR 26.17.02 regulations for improved water quality outcomes.
Best Management Practices (BMPs)
BMPs are non-structural and structural practices that effectively manage stormwater runoff, improving water quality and reducing pollution. They are essential for achieving Maryland’s stormwater management goals.
6.1 Types and Effectiveness
Best Management Practices (BMPs) include both non-structural and structural measures to effectively manage stormwater runoff. Non-structural BMPs, such as conservation design and impervious surface reduction, minimize environmental impact. Structural BMPs, like bioretention and infiltration systems, treat runoff directly. BMP effectiveness varies based on design, implementation, and site conditions, ensuring they meet water quality and quantity goals when properly applied.
6.2 Design and Implementation
Proper BMP design and implementation are critical for stormwater management success. Design considerations include site-specific conditions, runoff characteristics, and regulatory requirements. Implementation involves precise construction techniques, material selection, and adherence to approved plans. Post-construction inspections ensure functionality, while ongoing maintenance guarantees long-term performance and environmental benefits, aligning with MDE’s stormwater management goals for water quality protection and sustainable development practices.
Impervious Surfaces and Runoff Management
Impervious surfaces increase stormwater runoff, exacerbating erosion and pollution. Effective management strategies include reducing impervious areas and implementing green infrastructure to mitigate runoff impacts on water quality.
7.1 Impact on Stormwater
Impervious surfaces significantly alter natural hydrology by reducing infiltration and increasing runoff velocity and volume. This leads to enhanced erosion, flooding, and degraded water quality, as pollutants are transported more efficiently into waterways, harming aquatic ecosystems and increasing the risk of downstream environmental damage.
7.2 Management Strategies
Effective management of impervious surfaces involves implementing ESD practices like permeable pavements, rain gardens, and green roofs. These strategies reduce runoff by promoting infiltration and filtering pollutants. Regular maintenance of BMPs ensures their functionality, while ordinances and public education further support sustainable stormwater management, enhancing environmental protection and community resilience.
Maintenance and Inspection Requirements
The MDE SWM Manual outlines routine maintenance schedules, inspection frequencies, and record-keeping obligations to ensure stormwater management facilities function optimally and comply with regulatory standards.
8.1 Frequency and Procedures
Maintenance and inspections must occur annually, with additional checks after significant storms. Procedures include visual assessments, debris removal, and structural evaluations. Detailed records must be kept, ensuring compliance with MDE standards and submitted as required.
8.2 Reporting and Compliance
Reporting must occur annually, detailing inspection results, maintenance activities, and compliance status. Submissions must adhere to MDE formatting requirements. Non-compliance issues must be addressed promptly, with corrective actions documented and submitted to MDE. Records of all activities must be retained for at least five years, ensuring transparency and regulatory adherence.
Submission Requirements for SWM Plans
The SWM plan submission requires two copies of concept plans and reports, along with pre-concept meeting minutes if applicable. All documents must be submitted to Permits, Approvals and Inspections (PAI) for review and approval, ensuring compliance with Maryland’s stormwater management regulations.
9.1 Concept Plans and Reports
Submission requires two copies of concept SWM plans and reports, detailing site-specific stormwater management strategies. Pre-concept meeting minutes must also be included if applicable. These documents ensure compliance with Maryland’s stormwater regulations and provide a clear framework for review and approval by the appropriate authorities, as outlined in the MDE SWM Manual guidelines.
9.2 Permitting Process
The permitting process involves submitting all required documents to the Permits, Approvals, and Inspections (PAI) office. This ensures that stormwater management plans meet MDE standards and comply with state regulations. Proper documentation and adherence to guidelines facilitate a smooth approval process, as detailed in the MDE SWM Manual.
Institutional Stormwater Management Plans (IMPs)
Institutional Stormwater Management Plans (IMPs) outline strategies for managing stormwater at specific institutions, such as airports. BWI Marshall and Martin State Airports have approved IMPs, ensuring MDE compliance.
10.1 Case Studies (BWI and Martin State Airports)
The Maryland Department of the Environment (MDE) has documented Institutional Stormwater Management Plans (IMPs) for BWI Marshall and Martin State Airports. These case studies highlight the implementation of stormwater management practices, ensuring compliance with state regulations. Existing conditions have been approved by MDE, while future conditions planning is ongoing, demonstrating proactive environmental stewardship and regulatory alignment for large-scale institutions.
10.2 Future Conditions Planning
Future conditions planning ensures proactive stormwater management by anticipating environmental changes and development impacts. MDE requires institutional plans to address projected growth and climate trends, integrating adaptive strategies and innovative technologies; This approach ensures long-term compliance with regulations and maintains water quality, fostering sustainable stormwater management practices for future generations in Maryland.
The MDE SWM Manual guides effective stormwater management, ensuring environmental protection and compliance. Future updates will incorporate emerging trends, enhancing sustainability and water quality outcomes in Maryland.
11.1 Summary of Key Points
The MDE SWM Manual outlines essential strategies for stormwater management, emphasizing Environmental Site Design (ESD) and Best Management Practices (BMPs). It ensures compliance with regulations like the Stormwater Management Act of 2007 and COMAR 26.17.02. The manual also highlights the importance of maintaining water quality volumes (WQv) and implementing effective runoff management. Future updates will focus on emerging trends to enhance sustainability and water quality outcomes.
11.2 Emerging Trends in SWM
Emerging trends in SWM include the integration of green infrastructure, smart stormwater technologies, and climate-resilient designs. Advances in data-driven decision-making and real-time monitoring are enhancing efficiency. There is also a growing focus on community engagement and equitable access to SWM benefits. These innovations aim to address evolving environmental challenges and improve long-term water quality outcomes in Maryland.