Peterson Street Stormwater Bioretention Area


Green Stormwater Infrastructure in Urban Heat Islands

Using GSI to Mitigate Stormwater and Heat Island Effects

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.

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.

Project Details

$750,000 (Feasibility/Project Identification, Conceptual Design, Detailed Design, Permitting, Public Outreach, and Construction)
Project Lead:
Stormwater Management
Tetra Tech



Amy Farinelli
Stormwater Engineer

Lead Department:
Engineering Services
Service Unit:



This project supports

Raleigh's Climate Plan in Action


Tetra Tech is currently working to identify, evaluate, and prioritize potential GSI project types and locations throughout the City of Raleigh. After the top five sites are identified, further evaluation will take place to determine what GSI practice is best for each potential site before moving into design.

Project Goals

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. When implemented with tree canopy and other natural vegetative improvements, GSI is effective in reducing heat island impacts as well as reducing flooding for smaller, more frequent storm events. By using more natural elements, like 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.

As we design and implement these projects, we will have opportunities for public involvement and feedback. For more information and updates, email Amy Farinelli.

Lead Department:
Engineering Services


Detailed design and permitting is expected to begin in early 2024.

Lead Department:
Engineering Services




Early Summer 2023

Site identification and prioritization begins

Early Summer 2024

Project Design begins

Fall 2024

Project Design complete

Winter 2024

Public Meeting scheduled

Winter 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.