Success Story: Greenville Green Infrastructure

• In 2013, the City of Greenville began planning the Town Creek Culvert upgrade. In the same year, the City Council awarded the first contract for development of the City’s drainage plan. In 2014, the City approved the drainage plan.
• The City selected a construction consultant in 2016 and began project development in 2017. Culvert construction and repair took about three years, finishing in November 2020. Construction finished just over its initial estimate due to delays from major storms.
• Since the culvert runs under a road, the City redesigned and reconstructed portions of several streets in the process of constructing the culvert.
• Greenville added multiple stormwater drains to quickly divert floodwaters out of town during heavy precipitation.
• The City built water treatment stations along the culvert system to further treat stormwater runoff and remove pollutants before they can enter the Tar River.
• The City included permeable pavement, bioretention ponds, constructed vegetated areas along roadways, and the Town Common wetland in the project.
• Greenville partnered with East Carolina University to develop signage, a kiosk and other educational materials next to the Town Creek Culvert.
• The City also partnered with the Pitt County Health Department to plan and develop a greenway above the culvert. Pitt County received a grant for construction of the greenway in August 2023. Project managers expected greenway construction to finish in 2024.

The City of Greenville estimated the total project cost to be $33.3 million. Estimated costs include:

• $22.3 million for initial construction
• $5.7 million for professional services
• $2.3 million in contingency funds
• $600,000 in closing costs for the Clean Water State Revolving Fund
• $2.4 million for green infrastructure development 

Funding sources came from:

• Clean Water State Revolving Fund ($16 million loan)
• Greenville Utilities Commission ($3.4 million)

City of Greenville, East Carolina University, Pitt County Health Department

• The new culvert increases Greenville’s stormwater management capacity and mitigates flooding and water quality issues. The project includes 2,333 linear feet of reinforced concrete box culvert and 306 linear feet of reinforced concrete pipe culvert under the city.
• The wetland and vegetated zones help to reduce flooding. Signage adjacent to these features teaches residents about the importance of environmentally friendly solutions.
• East Carolina University conducted river sampling in the Tar River post construction. The University noted seeing lower nitrate, improved sediment retention and improved aquatic habitat in the river.
• Greenville City managers and East Carolina University described substantially reduced flooding in the new culvert portion of the city since the project’s completion.
• Greenville’s downtown area is highly urbanized with nearly 90% impermeable land cover. Including green elements like wetlands and vegetation in the project design offered planners a rare opportunity to add green infrastructure elements in an area where they would be unable to otherwise.

Greenville Director of Engineering Lisa Kirby said it is important to lean on other groups to fill in the gaps. Partners can bring in additional funding and expand project components. East Carolina University received multiple grants in addition to the City’s funding to research the history of the stream. The University developed educational materials to place around the city, constructed a kiosk along the newly constructed road and is designing an outreach plan to educate residents about the Town Creek Culvert.

Kirby also mentioned that project managers should always be thinking of how to incorporate environmentally friendly green and gray infrastructure into their projects. On its own, green infrastructure can be hard to sell to residents and elected officials. To gain support for its development, project managers can promote the economic benefits from green infrastructure’s flood management capabilities and tie it into larger economic development projects. Kirby also encouraged communities wanting to replicate the Town Creek Culvert project to be proactive in making sure residents and public officials understand what the result will look like. Invest in visual props and other tools to communicate the value of the project. The City of Greenville got artist renderings of how the final greenway would look downtown. The artist renderings, greenway, kiosk and other attractive elements really “sold” the project.