Green Stormwater Infrastructure in Urban Heat Islands

Urban Heat Islands (UHIs) are areas throughout the city with few trees, little green space or large areas of paved space that can experience substantially higher temperatures than areas with more shade and less paved area. Raleigh Stormwater is identifying ways to use green stormwater infrastructure (GSI) to reduce UHI effects.

Project Details

Type:: Stormwater
Budget:: $750,000 (Project Identification, Design, Permitting, Public Outreach, and Construction)
Project Lead:: Stormwater Management
Contractors:: Tetra Tech

Contact

Amy Farinelli
Stormwater Engineer
amy.farinelli@raleighnc.gov
919-996-4008

Lead Department:: Engineering Services

Service Unit:: Stormwater

This project supports

Raleigh's Climate Plan in Action

We identified and evaluated three potential locations to install GSI projects throughout the City of Raleigh.

Public Meeting

We recently held an open house to hear feedback from the public. Weren't able to attend? Check out the links below to learn more about the upcoming project areas.

Project Goal

The primary goal of this project is to use GSI to reduce the UHI effect and improve stormwater management in disproportionately impacted and vulnerable communities of Raleigh.

Benefits

When implemented with tree canopy and other plants, GSI can reduce heat island impacts and reducing flooding for smaller storms. By using plants and soil, these GSI projects will store water and absorb pollution into the ground when it rains, improving the quality and health of downstream waterbodies.

Project Locations

The project map shows locations of where green stormwater infrastructure (GSI) will be installed. For a full screen view, visit the GSI Project Map. Select the three lines on the map (upper right corner) to see what the icons mean.

Project Number	Location	Description
1	1713 Crest Rd	Stormwater runoff from Crest Road will drain into a bumped out bioretention in the roadway. A large tree will be planted in the bioretention to provide shade.
2	1000 Gregg St	Stormwater runoff flowing to the storm drain on Martin Luther King Jr. Blvd at the corner of Gregg St will be shifted to a bioretention area within a City-owned parcel. A large tree will be planted in the bioretention area to provide as much shade as possible to neighbors and other residents.
3	Levister Ct at Walnut Terrace	Stormwater runoff flowing to the storm drain on Levister Court will drain into a bioretention area that extends under the sidewalk using a suspended pavement system, or tree well. A large tree will be included for shade.

Schedule

Date	Activity
Summer 2023	Project kickoff
Fall 2023	Site identification, prioritization, and selection
Winter/Early 2024	Project design begins
February 24, 2024	Public meeting scheduled at John P “Top” Greene Community Center
Fall 2024	Project design complete
Winter/Early 2025	Construction begins
December 2026	Deadline for completing project and spending all ARPA funds

Summary of Project

Thermal Image of a tree at Chavis Park showing cooling effect of tree cover. — Thermal image of a tree in Chavis Park. This image shows the importance of tree canopy to provide cooling impacts on hot days. The baseball field behind the tree shows much higher temperature readings than the area under the shade of the tree.

The City previously conducted a study to collect data need to better identify the UHI locations within Raleigh. Find out more information, data collected from the study, and Raleigh’s heat islands interactive map on the Urban Heat Islands website.

GSI can help reduce the effects of UHI, while also storing rainwater and reducing localized flooding. The City has contracted with Tetra Tech to identify and design GSI opportunities to mitigate the impacts of climate change and UHI effect in disproportionately impacted communities. Proposed GSI will include plantings and street trees that improve shade in UHIs, while also providing water quality benefit.

This project is funded by the American Rescue Plan Act (ARPA) Funding. For more information on funding for this project, visit the ARPA Infrastructure Projects website.