Design & Build
The Journey of Designing & Building: Principles & Practices
Principle 1: Define Portoflio-level Design Goals
(This principle is critically important for practitioners with emerging programs and may not be relevant for more established or mature programs.)
Designing green infrastructure is like choreographing a ballet on a crowded stage. There are lots of players involved, each stakeholder has a role, and the performance only works when everyone is aligned on the overall goal. Most green infrastructure is highly visible (impacting local residents and businesses), requires maintenance (likely from the public works staff) and may use public assets like the right of way or publicly owned land. These public assets may also be used for moving pedestrian and vehicular traffic, public and private utilities and/or recreation.
That is why scalable, adaptable, and cost-effective green infrastructure starts with shared goals. In order to identify broad priorities for the green infrastructure portfolio, internal and external stakeholder engagement is essential. Additionally, understanding and considering regulatory requirements and funding realities will lead to more durable solutions over time.
Define internal priorities and capabilities.
Clarifying internal priorities and capabilities ensures that design standards are grounded in reality. Begin by establishing internal agency priorities, including regulatory drivers, maintenance capacity, funding restrictions, goals for equity and social justice, and risk tolerance. Identify potential risks associated with green infrastructure design and construction, such as performance uncertainty, liability, maintenance gaps, and long-term operations. Determine how these risks will be addressed or mitigated through the project approach. Build buy-in by coordinating across internal departments, such as transportation, utilities, and parks, to surface interagency priorities and identify potential conflicts. Develop a preliminary matrix that documents internal drivers, capabilities, and tradeoffs.
Identify key stakeholders and clarify their roles.
In many locations, the agency tasked with stormwater management does not have jurisdiction over the public rights of way or property where green infrastructure installations may be located. Additionally, the agency or department ultimately responsible for maintaining green infrastructure may not be the agency funding and constructing stormwater management improvements. To promote project and program success, early buy in from these stakeholders is critical. Identify organizations or individuals who bring essential knowledge, authority, land management, or influence over design outcomes, such as public agencies, utilities, elected officials, industry experts, and community leaders. Understand their priorities and seek to align portfolio-level green infrastructure goals across sectors. Consider how to effectively integrate broader objectives like climate resilience, economic development, public health, social equity, community impact, beautification, and workforce development. These organizations’ goals may identify opportunities to focus on specific portfolio-wide co-benefits, land-types and desired Best Management Practice (BMP) types, or to adapt to maintenance needs and constraints.
Set clear portfolio-level goals and metrics.
Establish shared goals that leverage green infrastructure’s multiple benefits. Articulate how success will be defined and measured at the portfolio level to drive eventual project-level reporting. Use community priorities to shape objectives and define metrics and reporting standards. Meet regulatory reporting requirements while maintaining flexibility to support broader project outcomes. Metrics should cover required outcomes, like volume reduction, rate control, and nutrient reduction. Conduct a detailed engineering planning study to quantify goals like volume reduction and geographic distribution. Metrics should also address co-benefits, like air quality improvement, job training completions, embodied carbon reduction. Other example metrics include percent canopy cover, habitat square footage added, increased knowledge of green infrastructure in the surrounding community, and lifecycle maintenance costs within a given annual cost target. Use the GSI Impact Hub, which is an interactive platform with tools, resources, and an impact calculator, to evaluate the multiple co-benefits of green stormwater infrastructure.
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- Resource: “How to Approach Evaluation” Section of the Equity Guide for Green Stormwater Infrastructure Practitioners
Build lasting agency partnerships and cross-disciplinary coordination.
Transparent, open communication with both staff and external partners can help build trust and cultivate partnerships that lay the groundwork for successful project portfolios. Establish strong relationships early with internal groups, such as stormwater, public works, utilities, traffic management, urban forestry, horticulture, and planning. Clarify roles and responsibilities and identify resource and capacity constraints that must be overcome for a successful program. Identify mutual benefits so collaborators gain value through the project portfolios. Promote cross-disciplinary collaboration between project professionals (e.g., engineers, landscape architects, contractors). Externally, cultivate long-term relationships with partner agencies through standing meetings and ongoing communication. Communicate not only project portfolio benefits but also limitations. Share how challenges will be addressed in future work. Explore delivery structures that enable collaboration across silos.
Establish transparent processes and feedback loops.
Document how decisions are made, recorded, and updated, especially when priorities shift, funding changes, or leadership turns over. Use tools like decision logs, meeting minutes, project charters, or Memoranda of Understanding (MOUs) to track stakeholder input and maintain institutional memory. The Equity Guide for Green Stormwater Infrastructure Practitioners outlines the step-by-step process of creating a Public Reporting Plan, which could be a useful tool in transparently sharing progress and remaining work in ways that reinforce public accountability and build trust over time. Regular schedules for revisiting goals and evaluating progress are another important process improvement, because stakeholders will have opportunities to learn from what is working and what is not. Learnings from those checkpoints should inform new targets, so build in flexibility to make meaningful and practical adjustments. Look for opportunities to engage the community along the way, and in ways that hold the program accountable to publicly shared goals.
Principle 2: Establish Design Standards
Adopting design standards for green infrastructure practices will result in installations with a higher probability of success. Each municipality possesses unique topography, geology, development patterns and infrastructure practices. Therefore, providing clear reference standards offers designers and contractors a roadmap for developing successful projects tailored to the unique aspects of your community.
Wherever feasible, leverage standards from peer jurisdictions and regional, state, or national models. Many county or state level governments have already developed design standards or requirements, some of which may be recommended practices while others may be required by statute. A thorough review and understanding of these requirements and recommendations will define the boundaries from which local standards can be further developed. Then start with existing design standards from other jurisdictions and adapt them to your unique environment and program goals. These design standards should be grounded in scientific research and adapted to reflect local climate, infrastructure, capacity, and community goals. Standards should support long-term maintenance, environmental resilience, and design excellence. Engaging teams involved during the implementation process is also crucial to developing standards that promote functional, construction-ready projects.
Build on existing best practices and expertise.
Review existing design standards from adjacent jurisdictions, peer municipalities, regional agencies and relevant state or national models. Identify elements that can be adopted or adapted, such as standard details, specifications, design criteria, planting palettes, and performance metrics. From these precedent examples, develop local design standards that align with shared goals and foster multiple benefits (e.g. meeting policy requirements, integrating community interests, addressing climate impacts, etc.). Invite perspectives from planners, engineers, designers, landscape architects, horticulturists, developers, construction managers, and maintenance staff to head off potential challenges from the outset. Apply these cross-departmental insights so that standards are practical, meet maintenance needs, and achieve long-term performance objectives.
Adapt to local conditions.
Standards that ignore local conditions and capacity can lead to missed opportunities, underperformance, and/or maintenance burdens. On the other hand, well-adapted standards raise the bar for best management practice (BMP) and system performance while helping municipalities manage long-term risk and cost. Gather community-level insights through workshops and other input opportunities using online tools; providing opportunities for learning and dialogue can help the team elevate and respond to socio-cultural, economic, and environmental realities. Reflect and respond to local environmental conditions, such as climate, geography, soil types, and plant communities. Align standards with local policy goals and regulatory frameworks while maintaining scientific rigor. To ensure the long-term success of Best Management Practices (BMPs), also factor in the capacity of local departments and partners to implement and maintain infrastructure. Maintenance of BMPs can be one of the most challenging aspects of green infrastructure. Many municipal entities do not have the expertise on staff, nor do they have the capacity to train workers to maintain elaborate plantings when rain gardens or bioretention facilities are installed. Special equipment must be purchased or contractors hired for maintenance of permeable surfaces. This equipment can be expensive and may not be available in some locations. If facilities are not designed in a way that is within the maintenance capacity of the program partners, the BMPs may not function properly or they may not be aesthetically pleasing and public support for green infrastructure practices will be diminished. The standards should also plan for and accommodate a range of project sizes. Finally, consider best practices from other cities to bring forward new insights and compare approaches.
Make standards user-friendly.
If standards are hard to interpret or apply, they will not be used consistently. Clear, user-friendly design standards improve design quality and review efficiency, while promoting high-quality implementation. Use plain language so standards are accessible for multiple audiences, including for planners, engineers, designers, reviewers, and contractors. Clearly distinguish between minimum requirements and recommended practices. Standardize language and definitions, and develop templates, submission procedures, and a centralized resource hub. Consider creating annotated versions of standards for training or review. Make standard construction details available in computer-aided design and drafting (CADD) software for use by designers. Ensure that materials specified in the design standards are readily available from multiple local sources.
Build in flexibility for innovation.
Standardization supports efficiency and consistency, but there are drawbacks to setting overly rigid standards. Strict guidelines can stifle innovation, limit creativity, and fail to respond to real-world complexity. Landscapes are dynamic systems influenced by changing climate, vegetation, and human use. Clearly define which elements of the standards are mandatory and any opportunities for changes. The elements that have flexibility enable municipalities to test new things and evolve their approach over time. One way to implement this is a component-based specifications model where designers have choices with certain elements. Provide guidance for piloting emerging practices and creative approaches that respond to evolving environmental, social, and technical conditions. Collaborate with community members and industry experts to pilot new strategies, such as alternative materials, planting methods, or hybrid infrastructure on a small scale before broader adoption. Create formal pathways for flexibility in areas like planting design, material selection, or site layout, where conditions or needs may vary. Consider design competitions, pilot projects, or research partnerships as mechanisms for exploring new ideas within a structured framework.
Resource: Green Stormwater Infrastructure Manual, Kansas City, Missouri
Establish ongoing feedback loops.
Without an established process to learn from past projects, project teams risk repeating mistakes and missing opportunities for improvement. Set up a regular review process for updating standards based on lessons learned from construction and inspection. Gather feedback from designers, inspectors, and maintenance teams. Incorporate post-construction monitoring data to refine future guidelines. Offer ongoing training to enhance consistent implementation.
Principle 3: Collaborate on Design
Developing successful green infrastructure project designs requires meaningful community engagement to strengthen design as well as close collaboration with internal teams across disciplines, perspectives, and phases. Engage community, operations and maintenance teams, agency partners, and industry experts early and throughout the process. Establish structured review processes to meet design standards. Support quality by training design reviewers and leveraging regional or national certifications. Collaborate with industry experts to improve both individual designs and broader design standards over time.
– Equity Guide for Green Stormwater Infrastructure Practitioners, Page 44
Engage community in meaningful ways. This best practice is inextricably linked with another chapter of the Framework of Practice, Center Equity. Community members and stakeholders can strengthen design by bringing their on-the-ground insights, requirements, relationships, and expertise to the table. Their feedback can surface local knowledge, cultural considerations, and potential risks that might otherwise be missed. Engage communities not just to inform, but to improve design outcomes. Assess interests of community members and stakeholders such as landowners, site facility representatives, and site users. Define the scope of community input and right-size engagement for each project. Partner with community-based organizations (CBOs) to engage key stakeholders, including communities where the infrastructure will be built. This is important because engagement at this stage of design will help ensure that the project reflects local priorities.
Example: How Chicago, Illinois Worked with the Community to Design the Wild Mile
Involve Operations and Maintenance early.
Operations and Maintenance (O&M) staff can readily identify design elements that set BMPs up for long-term success. O&M insights can lead to methods that enhance or hinder safety, clarify maintenance needs, and recommend feasible equipment, materials, and access strategies. Engage O&M teams at the outset of design to improve feasibility, long-term usability, and safety. Draw on their deep knowledge of maintenance realities to shape practical designs. Involve maintenance staff and horticulturists in planting design to ensure species are locally appropriate, maintainable, and visually successful. Foster a two-way exchange of knowledge by facilitating opportunities for designers to understand O&M practices. In return, O&M teams can build an understanding of green infrastructure functions, such as how specific systems manage flow, where inlets and outlets are located, and how performance can be observed or adjusted. Document lessons learned and create structured feedback loops so that maintenance insights can refine future design standards and specifications.
Collaborate with industry experts.
Designers cannot do it alone. Working together with suppliers, contractors, and researchers can lead to better outcomes by gaining critical on-the-ground and emerging insights. Engage a variety of industry professionals early in the design process to ground ideas in what is practical, constructible, and locally available. These experts can flag issues with material lead times, installation methods, or long-term durability that may not be evident on paper. Use pre-bid meetings, vendor demonstrations, or design charrettes to gather input on new materials or construction techniques. If available, connect with local colleges, universities, and research institutions where green infrastructure studies are underway. Academic partners can offer data on performance, help test new approaches, and identify emerging climate-adaptive strategies. Collaborating with educational institutions can also create pathways for pilot projects and student involvement
Strengthen design review and verification processes.
A thoughtful design review process with supportive staff resources creates the conditions needed for project success. Establish methods and resources to support the teams responsible for reviewing designs to ensure they meet applicable standards and project goals. Provide training and guidance for design reviewers to promote consistency and quality. Use checklists, peer reviews, and pre-submittal meetings to flag issues early. Encourage reviewers to pursue regional or national certifications, such as the National Green Infrastructure Certification Program, to build shared understanding of green infrastructure principles. Arrange for review staff to visit active green infrastructure construction sites to understand the processes and challenges of the construction process. Ensure that there is a feedback process between the construction contractor, the municipal entity’s construction inspector and the keeper of the design standards. Document outcomes to improve future reviews and refine design standards.
Resource: Philadelphia Water’s Stormwater Management Guidance Manual
Principle 4: Ensure Quality Construction
Improving long-term performance requires multiple strategies to manage and assure quality during construction. Approaches include prequalifying skilled contractors, strategically sequencing construction, minimizing environmental impacts, establishing consistent maintenance schedules before project completion, conducting rigorous monitoring, and integrating real-time feedback to refine future projects.
Use qualified contractors and plan for specialized needs.
Assess the availability of experienced green infrastructure contractors working in the area to determine if a skills and knowledge gap exists. This assessment can be done through sending out a Request for Information (RFI) to contractors that currently bid on work within the municipality, through conversations with nearby municipal entities that have more advanced green infrastructure programs, or via other survey methods. If a skills gap is found to exist, consider developing a municipal-run training program for contractors or requiring that a contractor’s job superintendent obtain a certification from an outside training program such as the National Green Infrastructure Certification Program. In lieu of these approaches, if your construction inspection staff is knowledgeable in construction of green infrastructure, assign an inspector to projects that can both inspect the projects for conformance with the plans and specifications and teach the contractors’ field crews why certain aspects of green infrastructure are different from traditional construction and why they matter to the performance of the BMP. When possible, use “best value” procurement over low-bid selection to ensure quality work, recognizing that local and state procurement rules may constrain this approach. When low-bid selection is required, consider using a contractor prequalification requirement as discussed above. Mitigate risks by ensuring bid packages include clear, detailed contract documents (e.g., plans and specifications) and requirements for critical tasks like watering. Avoid poorly defined scopes that can result in inadequate delivery and failed vegetation by aligning needs, expectations, and detailing clear requirements. Where internal capacity is limited, consider hiring specialized firms to lead design, installation, and early maintenance for select projects. These firms can train municipal staff along the way, creating capacity while delivering high-quality outcomes. Consider alternative project delivery methods, such as design-build contracting, that can support early collaboration and improve constructability, particularly for high-impact or complex green infrastructure projects.
Example: How San Francisco has Built a Qualified Vendor Base to Support Green Infrastructure
Sequence construction carefully to minimize impacts.
Consider and apply a full toolbox of strategies to minimize or avoid construction impacts, particularly when green infrastructure is only one component of a larger project. Plan and sequence construction to prevent impacts such as erosion, soil compaction, sedimentation, and damage to permeable surfaces. Stabilize drainage areas before green infrastructure installation and conduct infiltration testing after excavation. Avoid compacting soils where infiltration is needed. Plan to decompact subsoils and install bioretention soil media (BSM) loose, with no traffic afterward. Coordinate staging and erosion control (e.g., sandbags, mulch, sediment basins) with construction management teams to protect systems and minimize runoff contamination. Schedule construction during dry weather when possible and align with permits. In dry climates, include temporary irrigation during planting. In alignment with the guidance in the Equity Guide, minimize and communicate anticipated construction-related disruptions in a way that builds trust and relationships with impacted communities. Use temporary signage during construction to communicate the purpose of the project and explain disturbances. Clear signage helps educate the public, maintain safety, and build support for the project by reinforcing the long-term benefits of green infrastructure improvements.
Resource: San Francisco’s Green Stormwater Construction Guidebook
Conduct active construction monitoring.
Establish a clear quality assurance and quality control (QA/QC) process to catch issues early and prevent costly fixes. Clearly identify the materials submittals required by the specifications and ensure that the approved materials are what is delivered to the site. At the time of the preconstruction meeting, identify the critical components of the BMP construction, share the rationale behind them, and establish times when inspections will be required. Plan inspections at key milestones (e.g., grading and concrete forming, underdrain installation, final planting). Require inspection stages in contracts, and ensure inspectors are trained in green infrastructure-specific practices. When a contractor is new to green infrastructure work, use inspections as a learning tool for contractors and crews, especially early in a program. Often the unique requirements of green infrastructure construction are not relayed to the workers in the field. Field inspections during construction can correct improper construction methods before reaching a milestone inspection. These interim inspections can head off work that is not being installed correctly and reduce or eliminate rework which is beneficial for all parties involved. Verify a range of elements beyond grading, compaction, and vegetation, including conformance with material specifications, elevations, and underdrain configurations. Maintain thorough as-built documentation to support future maintenance and system performance.
Establish ongoing feedback loops.
Collaboration between key parties including the owner, designers, contractors, and maintenance staff can prompt discovery of performance issues and identify solutions that enhance long-term functionality. Create a post-construction review process to capture lessons learned from each project and immediately apply insights to future work. Rather than waiting for periodic updates to design standards, use real-time construction feedback to refine project design processes and improve efficiency. Consider organizing O&M/Asset Management and the capital green infrastructure delivery on the same team. Host post-construction project reviews to identify lessons learned and actions for improving design standards and processes.
Plan for the handoff to O&M.
Planning ahead for the establishment period, one of the most vulnerable times for a new green infrastructure installation, can save significant time and money. Based on the capacity and capabilities of the entity responsible for final maintenance, the handoff of planted material can vary to obtain the best final result. Entities that are well equipped to take on the maintenance may be best suited to accept the care of plantings immediately after installation. Those entities that are not as well-resourced may consider paying the contractor to maintain the installation for a year or more. After evaluating which method is best for you, clarify responsibilities and timelines for the post-construction phase, including warranty periods, final inspections, and the transition to long-term maintenance in the construction contract. Engage maintenance staff during design reviews and inspections to ensure practicality and ownership. Set expectations for plant establishment and replacements in contracts to avoid gaps in care. When possible, build in a short “commissioning” phase to troubleshoot issues before full handoff.
Resource: Urban Stormwater Controls: Operation and Maintenance (WEF Manual of Practice No. 39), American Society of Civil Engineers and the Water Environment Federation