Stormwater Management in Western Washington
The Washington State Department of Ecology (DOE) publishes stormwater manuals which comply with regulations. The DOE issues a National Pollution Discharge Elimination System (NPDES) Permit to the City of Poulsbo, and one of the permit requirements is that the City adopt the 2019 Stormwater Management Manual for Western Washington.
Introduction
Stormwater management is a critical aspect of environmental protection in Western Washington, a region characterized by abundant rainfall and a complex network of waterways. The Stormwater Management Manual for Western Washington (SWMMWW) serves as a comprehensive guide for managing stormwater runoff, aiming to minimize its negative impacts on water quality, flood risks, and overall ecosystem health. This manual, developed and updated by the Washington State Department of Ecology (DOE), provides essential guidance for communities, developers, engineers, and other stakeholders involved in managing stormwater within the region.
The Washington State Department of Ecology’s Role
The Washington State Department of Ecology (DOE) plays a pivotal role in overseeing stormwater management throughout the state. The DOE is responsible for developing and enforcing regulations that govern stormwater discharges, ensuring compliance with the Clean Water Act and other environmental protection laws. The DOE’s authority extends to issuing permits for stormwater discharges, conducting inspections, and providing technical assistance to local governments and other entities. The DOE’s commitment to sustainable stormwater management is evident in the development and ongoing updates of the Stormwater Management Manual for Western Washington (SWMMWW), a vital resource for implementing effective stormwater practices in the region.
The Stormwater Management Manual for Western Washington (SWMMWW)
The Stormwater Management Manual for Western Washington (SWMMWW) is a comprehensive guide developed by the Washington State Department of Ecology to provide guidance on managing stormwater runoff in Western Washington. The manual offers a framework for local governments and other entities to implement effective stormwater management practices, addressing both the quantity and quality of stormwater runoff. The SWMMWW provides guidance on a wide range of topics, including site planning, stormwater runoff control, water quality protection, and the selection and implementation of Best Management Practices (BMPs). The manual is a valuable resource for engineers, developers, and other professionals involved in stormwater management, promoting responsible development and environmental stewardship.
History and Revisions
The Stormwater Management Manual for Western Washington (SWMMWW) has undergone several revisions since its initial publication, reflecting evolving scientific understanding, technological advancements, and regulatory changes. The first edition of the SWMMWW was published in 2001, and subsequent revisions were released in 2005, 2012, and 2019. Each revision incorporated updates to reflect current best practices and address emerging environmental challenges. The 2019 edition, in particular, incorporated new guidance on green infrastructure, stormwater treatment, and the management of contaminated stormwater runoff. These revisions ensure the manual remains relevant and effective in guiding stormwater management practices in Western Washington.
Key Features and Guidance
The Stormwater Management Manual for Western Washington (SWMMWW) provides comprehensive guidance on stormwater management practices for new development and redevelopment projects in the region. It outlines a range of strategies for controlling the quantity and quality of stormwater runoff, encompassing both traditional and innovative approaches. The manual emphasizes the importance of source control, which involves minimizing the generation of stormwater runoff at its source. It also promotes the use of Best Management Practices (BMPs), which are structural and non-structural measures designed to manage stormwater runoff and protect water quality. The SWMMWW provides detailed guidance on the design, installation, and maintenance of BMPs, including bioretention systems, infiltration trenches, and rain gardens. It also includes information on regulatory requirements, permitting procedures, and compliance monitoring.
Implementation and Compliance
The implementation and compliance of the Stormwater Management Manual for Western Washington (SWMMWW) are critical aspects of ensuring effective stormwater management in the region. Local governments and municipalities play a crucial role in implementing the manual’s guidelines by incorporating them into their local ordinances, regulations, and permitting processes. The manual provides specific requirements for stormwater management practices, including site planning, design criteria, and construction specifications. Local jurisdictions are responsible for enforcing these requirements through the issuance of permits, inspections, and compliance monitoring. The SWMMWW also encourages the use of innovative approaches to stormwater management, such as green infrastructure and low-impact development techniques. By fostering collaboration among stakeholders, promoting public awareness, and providing technical assistance, the manual aims to facilitate the successful implementation of sustainable stormwater management practices throughout Western Washington.
Local Regulations and Ordinances
Local regulations and ordinances play a crucial role in the implementation of the Stormwater Management Manual for Western Washington (SWMMWW). Local governments are responsible for adopting and enforcing stormwater management requirements that align with the manual’s guidelines. These regulations typically cover aspects such as site design, stormwater runoff control, water quality protection, and construction activities. They may also include specific requirements for the use of Best Management Practices (BMPs), such as bioretention ponds, infiltration trenches, and rain gardens. Local ordinances often incorporate the SWMMWW’s technical specifications and design standards to ensure consistency and compliance with state-wide stormwater management goals. By enacting and enforcing these regulations, local jurisdictions contribute to the protection of water quality, the reduction of flooding risks, and the overall sustainability of stormwater management in Western Washington.
Permit Requirements and Enforcement
The Stormwater Management Manual for Western Washington (SWMMWW) is closely tied to permit requirements and enforcement mechanisms. The Washington State Department of Ecology (DOE) issues permits, primarily the National Pollution Discharge Elimination System (NPDES) permit, to regulate stormwater discharges. These permits often incorporate the SWMMWW’s standards and guidelines, requiring developers and municipalities to adhere to the manual’s recommendations for stormwater management. The DOE, along with local agencies, is responsible for enforcing these permit requirements through inspections, monitoring, and enforcement actions. This includes verifying that construction projects comply with the SWMMWW’s design standards and that BMPs are properly installed and maintained. Violations of permit requirements can result in fines, penalties, and other corrective actions, ensuring that stormwater management practices are implemented effectively and that water quality is protected.
Best Management Practices (BMPs)
The Stormwater Management Manual for Western Washington (SWMMWW) emphasizes the use of Best Management Practices (BMPs) to effectively manage stormwater runoff and protect water quality. BMPs are a range of structural and non-structural techniques designed to control the quantity and quality of stormwater runoff. The manual provides detailed guidance on various BMPs, categorized into two primary areas⁚ stormwater runoff control and water quality protection. BMPs for stormwater runoff control focus on reducing the volume and velocity of runoff, often employing practices like infiltration trenches, bioretention cells, and rain gardens. Water quality protection BMPs aim to remove pollutants from stormwater before it reaches waterways, incorporating techniques such as filter strips, sedimentation ponds, and stormwater treatment devices. The SWMMWW highlights the importance of selecting and implementing the most appropriate BMPs for specific site conditions and development projects.
Stormwater Runoff Control
The Stormwater Management Manual for Western Washington (SWMMWW) emphasizes the importance of controlling stormwater runoff to mitigate flooding and erosion risks. The manual provides detailed guidance on various techniques for managing stormwater runoff, aiming to reduce its volume and velocity. These techniques include infiltration practices, such as infiltration trenches and rain gardens, which allow stormwater to slowly seep into the ground, replenishing groundwater and reducing runoff. Another effective approach is the use of bioretention cells, which are vegetated depressions designed to capture and filter stormwater, promoting infiltration and reducing runoff volume. The SWMMWW also promotes the use of detention ponds, which temporarily store stormwater and release it at a controlled rate, reducing peak flows and minimizing downstream flooding. These stormwater runoff control practices are essential for managing the effects of urbanization and protecting water resources in Western Washington.
Water Quality Protection
The Stormwater Management Manual for Western Washington (SWMMWW) places a strong emphasis on protecting water quality, recognizing that stormwater runoff can carry pollutants that degrade water bodies. The manual outlines best management practices (BMPs) designed to prevent pollutants from entering stormwater systems. These BMPs include the use of swales, which are vegetated channels that slow down stormwater flow and filter out pollutants. Stormwater treatment devices, such as filter boxes and sand filters, are also recommended to remove pollutants before stormwater is discharged into waterways; The SWMMWW also emphasizes the importance of source control, which aims to reduce the generation of pollutants at their source. This includes proper management of construction sites to prevent soil erosion and sediment runoff, as well as minimizing the use of fertilizers and pesticides that can contaminate stormwater. The manual stresses the importance of protecting water quality for both ecological and human health, recognizing that clean water is essential for a thriving ecosystem and a healthy community.
Resources and Information
The Washington State Department of Ecology (DOE) provides a wealth of resources and information related to stormwater management in Western Washington. The DOE’s stormwater website serves as a central hub for information on the Stormwater Management Manual for Western Washington (SWMMWW), including the latest revisions, guidance documents, and best management practices. The website also offers training materials, technical assistance, and links to relevant publications. In addition to the DOE’s website, there are a number of other sources of information on stormwater management. The Puget Sound Partnership, for example, provides resources on stormwater management in the Puget Sound region, with a focus on protecting the health of the Sound. Local governments and watershed groups often have their own websites and resources related to stormwater management in their jurisdictions. These resources can provide information on local regulations, ordinances, and permit requirements. The SWMMWW itself provides guidance on the measures necessary to control the quantity and quality of stormwater, emphasizing the importance of sustainable practices and protecting water quality.
Ecology’s Stormwater Website
Ecology’s stormwater website serves as a comprehensive resource for all things stormwater in Western Washington. It provides access to the latest edition of the Stormwater Management Manual for Western Washington (SWMMWW), including the 2019 edition. The website features guidance documents, best management practices, and training materials to help communities, developers, and engineers navigate the complexities of stormwater management. The website also offers technical assistance and support, ensuring that individuals and organizations have the tools they need to implement effective stormwater management practices. The website is organized by topic, making it easy to find the information you need, whether you are looking for guidance on specific stormwater control measures, information on permit requirements, or resources for education and outreach. Ecology’s website is an essential tool for anyone involved in stormwater management in Western Washington, offering a wealth of information and resources to help protect water quality and ensure the health of our waterways.
Other Relevant Publications and Manuals
Complementing the Stormwater Management Manual for Western Washington (SWMMWW), a range of additional publications and manuals provide valuable insights and guidance for stormwater management professionals and stakeholders. The “Construction Stormwater Pollution Prevention” volume of the SWMMWW offers detailed information on controlling pollution from construction activities. The City of Auburn’s “COA Supplemental Manual” serves as a valuable resource for communities seeking to implement the SWMMWW’s principles. These publications, along with various technical reports and research papers on topics like bioretention soil mix review and porous asphalt pavement performance, offer a deeper dive into specific aspects of stormwater management, contributing to a comprehensive understanding of the field. These resources provide practical guidance, technical specifications, and best practices for addressing the challenges of stormwater management in Western Washington, ultimately fostering a cleaner and healthier environment for all.