Tetra Tech is helping the City of Raleigh, North Carolina, advance green stormwater infrastructure (GSI) and low impact development (LID) through three phases of program development and implementation.

City staff and elected officials wanted to move forward on the City’s vision for a greener Raleigh as documented in the City’s Comprehensive Plan. Tetra Tech supported the three phases of implementing this vision, including:

  1. Scoping to determine barriers, needs, and opportunities and to develop a strategic work plan outlining tasks that the City needed to accomplish to begin building the framework that would support implementation of a GSI program
  2. Building capacity in the city for administration and implementation
  3. Implementing new policies, procedures, and necessary tools

Under the scoping phase, seven key City departments formed a task force to identify challenges and provide input on a work plan. The task force identified more than 60 challenges in creating a more sustainable Raleigh, including revising the City’s Unified Development Ordinance (UDO) to remove barriers to implementation of GSI and integrating City operations to enhance City applications as well as incentivize private development use of GSI. Tetra Tech facilitated six work sessions to review past implementation efforts and develop an improved implementation plan for advancing GSI and LID to help address the task force’s concerns. The City Council unanimously adopted the plan outlining tasks to update codes and policies, procedures, and tools.

Tetra Tech has served the City of Raleigh as a true consultant, not merely a vendor delivering a product. They have brought national and international experience and expertise, including first-hand knowledge of what has worked and not worked in other municipalities. Over the six-plus years they have supported us with GSI, they have learned our programs, policies, and procedures in ways even our own staff haven’t known. As important, they have worked alongside City staff and have come to understand how we make decisions and where we have constraints, bottlenecks, and even resistance to advancing GSI. The insight Tetra Tech provides through this institutional knowledge is extremely valuable.

Kevin Boyer, water quality supervisor and contract manager, Stormwater Management Division

Under the capacity building phase, Tetra Tech facilitated two multidisciplinary work groups to execute the work plan. Based on the groups’ results and recommendations, Tetra Tech developed revised codes and policies; templates for incorporating GSI in street rights-of-way; incentives, including an expedited Green Raleigh Review process; fact sheets; a framework for maintenance of stormwater best management practices; and a conceptual design for a cost tool. Detailed reports with recommendations along with the completed support tools were presented to the City’s department leaders, who endorsed the recommendations and the tools. Tetra Tech supported the City’s staff in preparing text changes for 27 sections of the UDO to remove barriers and encourage use of GSI and LID, which the City Council unanimously approved. Tetra Tech also helped revise the City Streets Manual in light of the code changes.

The implementation phase is preparing City staff to be both agents of change in advancing GSI and LID and collectively responsive to private development entities wanting to incorporate GSI and LID in development projects. Our team is helping internal City project designers and external private developers understand the revised codes and how to interact effectively between departments and programs to eliminate project barriers. Tetra Tech also is leading the development of an online cost tool to help the City work with design engineers to evaluate GSI and LID opportunities for City capital projects and encourage use of GSI and LID in private development. Tetra Tech provides other implementation assistance, including design review and consultation, on City projects on an as-needed basis.

While still early in the implementation period, the City already is beginning to see its vision take hold. Individual capital improvement plan projects including roadway projects, park plans, and building plans are evaluating and incorporating GSI and the City is cost sharing for certain property stormwater retrofits that include GSI. The future for Raleigh is not only brighter, but greener.


The City of Raleigh received the prestigious Program Excellence Award for Community Sustainability at the International City/County Management Association 104th Annual Meeting. The award was given to the City in recognition of the GSI and LID program, which Tetra Tech has supported from inception through implementation.