Climate Safe Neighborhoods
Explore Groundwork New Orleans' climate resiliency planning and advocacy work.
Community members painting a group art project at the 7th Ward community event for Trash-Free Waters campaign.
As part of the Climate Safe Neighborhoods (CSN) partnership, Groundwork New Orleans is working with residents and stakeholders to explore the relationship between the city’s history of housing segregation and the current and predicted impacts of the climate crisis.
Historical redlining maps and modern satellite imagery reveal a relationship between federal race-based housing segregation and vulnerability to extreme heat and flooding in New Orleans today. To address this relationship, Groundwork New Orleans is working closely with residents and stakeholders to build their capacity to self-advocate for climate adaptation measures.
Scroll down for a guided tour of our analysis, focus communities, and efforts to make New Orleans' neighborhoods safer from extreme heat and flooding.
Left: The Claiborne Avenue overpass at 1600 Kerlerec St, an example of high impervious surface landscape. Right: A path in New Orleans City Park near Dreyfous Dr., an example of a landscape with significant tree canopy.
What Does Race Have to do with the Climate Crisis?
Neighborhoods in New Orleans will not experience the impacts of climate change equally. Communities with fewer trees and green spaces are more vulnerable to heat and flooding, and those communities, nationwide, tend to be places where low-income residents and people of color live. It is no coincidence that these neighborhoods lack the green open spaces that mitigate heat and flooding. It’s the result of a long history of federal-instituted segregation.
Redlining and the US Government
In 1933, the federal government established the Home Owners’ Loan Corporation (HOLC) as part of a New Deal program to stabilize and encourage homeownership during and after the Great Depression through the introduction of long-term federally backed mortgages.
The HOLC provided guidance to private lenders on which neighborhoods were considered “safe” or “risky” for receiving loans. To develop this guidance, the federal government hired private surveying companies to develop “residential security maps” like the one below.
HOLC Residential Securities Map of New Orleans, 1939.
In addition to the quality of housing stock, race and ethnicity were the primary qualifiers of that risk. The “safest,” or greenlined, neighborhoods were graded A and contained high quality homes and “white” residents. The “riskiest,” or redlined, neighborhoods were graded D and contained poorer quality homes and African American, Eastern European and Southern Italian immigrants.
Residents in redlined areas could not receive loans to purchase homes in those neighborhoods. They were also prevented from buying homes in greenlined areas by realtors, lenders, and residents fearful of plummeting housing values. Neighborhoods of color saw property values drop or stagnate, and city-led improvements to infrastructure stalled. Today, nearly 75% of the neighborhoods graded as high-risk under the HOLC are low-to-moderate income, and 64% are neighborhoods of color.[ 1 ]
A Dangerous Legacy
How do the housing segregation practices of the past connect to the built environment of today? The bar graph below explores the relationship between modern tree canopy cover, impervious pavement, mean land surface temperature, and HOLC neighborhood grade for urban areas with redlining maps participating in the CSN partnership.
Participating CSN cities with redlining maps include: Denver, CO; Haverhill, MA; Kansas City, KS/MO; Milwaukee, WI; New Orleans, LA; Providence, Pawtucket, and Central Falls, RI; Richmond, VA; San Diego, CA; Union County, NJ; and Yonkers, NY. The values in this chart are normalized to allow comparison across cities. All of the raw values in the data set have been scaled from 0-100 by taking an individual value as a percentage of the range. The values were then averaged across all HOLC neighborhoods. The graph shows that on average for all participating CSN cities, tree canopy decreases with HOLC grade while impervious surface and land surface temp increase as HOLC grade moves from A to D.
Moving from grade A to grade D, tree canopy cover (green) decreases, impervious pavement (grey) increases, and mean surface temperature (red) increases. While this graph does not directly address flooding, we do know that high amounts of pavement in a neighborhood increase the local risk of flooding.
The data suggests that there is a relationship between historical practices of redlining, community infrastructure, and exposure to heat and flood risk. Our neighborhoods do not look the way they do by accident, and we will not reduce disparities in exposure to heat and flooding by accident.
Historical Segregation and Environmental Risk
The following maps explore the relationship between federally endorsed HOLC neighborhood grades and three environmental factors associated with climate risk: tree canopy cover, impervious surfaces, and land surface temperature.
Residential Security Map
Legend from HOLC Residential Securities Map, New Orleans, 1939.
By matching historical maps to their real-world locations using Geospatial Information Systems (GIS), the original images can be digitized and used for analysis. This HOLC “residential security map” of New Orleans was georeferenced by Mapping Inequality.[ 2 ] Here, it’s visualized on top of a base map of modern-day New Orleans. Navigate the map by clicking and dragging. Zoom in and out using the “plus” and “minus” buttons on the bottom right.
Map: Original HOLC Residential Securities Map georeferenced by Mapping Inequality. Navigate the map by clicking and dragging. Zoom in and out using the “plus” and “minus” buttons on the bottom right. View the legend by clicking the circular button in the bottom left corner of the map.
Digital Redlining Boundaries
A schematic of the raster to vector conversion.
These boundaries have been digitized by Mapping Inequality[ 3 ] from the original HOLC map. The line features are now living boundaries within which it is possible to conduct an analysis of other data layers. Here, we’ll be examining tree canopy cover, impervious surface, and surface temperature.
Map: Digital HOLC neighborhood boundaries digitized by Mapping Inequality.
Tree Canopy and Impervious Surfaces
A path in New Orleans City Park near Dreyfous Dr., an example of a landscape with significant tree canopy.
Tree Canopy: Neighborhoods with denser tree canopies are cooler than neighborhoods with less-dense tree canopies. Neighborhoods with more trees also reduce the risk of flooding since water seeps into the surrounding soil and is absorbed by plant roots. As a result, tree canopy reduces the risk of both heat and flooding.
The Claiborne Avenue overpass at 1600 Kerlerec St, an example of high impervious surface landscape.
Impervious Surfaces: Impervious surfaces, such as roads, sidewalks, parking lots, and driveways work against the cooling and flood mitigation benefits of trees. First, they prevent rain from being absorbed into the ground, increasing the pooling of water at the surface and stressing sewer systems, which can lead to sewer overflows. Second, they absorb and slowly release the sun’s heat back into the neighborhood- a phenomenon known as the Urban Heat Island Effect. Communities with more impervious surfaces can be several degrees hotter than neighborhoods with less pavement. Research conducted by Jeremy Hoffman and Vivek Shandas in 2020 found that formerly redlined neighborhoods are on average 4.5 ℉ hotter than their formerly greenlined counterparts. This difference can be as extreme as 20℉ within the same city.[ 3 ]
Map: Tree Canopy Cover and Impervious Surface from the National Land Cover Database 2016.[ 4 ] Each pixel in the image represents a 30 meter by 30 meter area on the earth's surface. The value of a cells color represents the percentage impervious surface or tree canopy cover in that square area. The greener the cell, the higher the tree canopy. The darker grey the cell, the more impervious surface.
Click the link below to compare tree canopy and impervious surface to redlining boundaries:
Surface Temperature
Low tree canopy cover and high impervious surface can lead to increased heat. In this map, the redder the area, the hotter the surface temperature was on summer days between 2015 and 2020. In comparison to the showing impervious surface and tree canopy, it is apparent that areas with fewer trees and more pavement tend to have higher surface temperatures. Furthermore, when are overlaid, we can see that areas with higher temperatures are more likely to be areas that were redlined in the 1930s.
Map: Mean Surface Temp calculated by Groundwork Milwaukee with assistance from Ben Faber using LANDSAT 8, 2015-2020, June-August, <20% cloud, no water. Calculated using code documented in the following article: Ermida, S.L., Soares, P., Mantas, V., Göttsche, F.-M., Trigo, I.F., 2020.Google Earth Engine open-source code for Land Surface Temperature estimation from the Landsat series. Remote Sensing, 12 (9), 1471.[ 5 ]
Click the link below to compare surface temperature to redlining boundaries:
HOLC Grades and Environmental Risk Factors
The graph below explores the relationship between tree canopy cover, impervious surface, mean surface temperature, and HOLC neighborhood grade in New Orleans. Moving from grade A to grade D, tree canopy cover (green) decreases, impervious surface (grey) increases, and mean land surface temperature (red) increases. While this graph does not directly address flooding, we do know that high percentages of impermeable pavement in a neighborhood increase the local risk of flooding.
Surface Temperature and Impervious Surface increase as HOLC grade decreases while Tree Canopy increases with neighborhood grade.
The data suggests there is a relationship between historical practices of redlining, development of public infrastructure, and exposure to heat and flood risk in New Orleans.
Which Neighborhoods are More at Risk?
But what do we know about residents’ ability to deal with or bounce back from the impacts of climate change?
Heat Vulnerability Index
Using a common methodology that adopts a definition of vulnerability composed of measures of exposure, sensitivity, and adaptive capacity, Groundwork developed a heat vulnerability index (HVI) based on work by Jeremy Hoffman in Richmond, VA.[ 6 ] The HVI considers surface temperature , tree canopy cover , impervious surface , and the percentage of households in poverty . Percentage of households living in poverty was chosen as a measure of adaptive capacity because the lowest-income residents in an area will find it most difficult to absorb the shock of extreme weather events (for example, paying medical bills associated with heat-related illnesses).
Map: A Heat Vulnerability Index considering exposure to risky environmental conditions (surface temperature, pavement, low tree canopy) and the capacity to cope with the consequences of exposure (households in poverty). Indices allow us to consider multiple variables at once. By including social variables along with physical characteristics, we consider not only which physical places require investment, but also which residents should be prioritized.
Several in the 7th Ward are among the most vulnerable to heat according to the index.
Click the link below to compare the heat vulnerability index to redlining boundaries:
Heat and Flood Vulnerability
This map examines the intersection of heat and flood vulnerability. Block groups in the upper quartile of HVI values are red. Census block groups that are in the upper quartile of households in poverty (%) and intersect FEMA Flood Hazard Zones are green, and block groups that meet both conditions appear as purple. When the vulnerability maps are overlaid with , we see a relationship between redlined areas and low-income areas with high heat and flood vulnerability. Groundwork New Orleans has chosen to focus its advocacy efforts in the 7th Ward because of their vulnerability to heat and flooding.
Map: High vulnerability or "priority" block groups. There are three categories: 1) block groups in the upper quartile of HVI, 2) block groups in the upper quartile of Households in Poverty (%) that intersect FEMA flood zones, 3) block groups that meet both conditions.
Click the link below to compare priority block groups to redlining boundaries.
Aerial view of the 7th Ward looking southeast over Bayou Street (Google Earth).
The 7th Ward
As the third largest of seventeen wards in New Orleans (indigenously named, “Bulbancha”), the 7th Ward is home to over 11,000 people. It stretches from the Mississippi Riverfront to Lake Pontchartrain and rests on Native Choctaw lands. The 7th Ward is full of vibrant culture, beautiful architecture, rich history, and was once the epicenter for Black advancement in the city.
The 7th Ward of New Orleans.
Rich History
Painting of A. P. Tureaud from the Louisiana Supreme Court.
Much of the neighborhood, particularly along Claiborne Avenue in the 19th and 20th century, was characterized by successful family-owned businesses such as laundromats, funeral homes, insurance companies, and barbershops. The 7th Ward was home to one of the most prominent figures of the Civil Rights movement, A.P. Tureaud, who was a lawyer for the New Orleans branch of the NAACP.
Right: A photograph of historical Claiborne Avenue taken in 1947.
Claiborne Avenue
All Saints Day Second Line Parade on Claiborne Ave. 2009.
Although the historic Black business district on Claiborne Avenue was severed by the construction of the highway in the 1960s, the roots of this neighborhood, family businesses, and many of its historic sites remain intact today. The area continues to actively embody its history through vivacious Second Line parades, gatherings, live music, and crawfish boils.
Right: An aerial image of Claiborne Avenue at St. Bernard Circle from 1942 prior to the I-10 Freeway construction compared to the same section of Claiborne Avenue in 2016, long after the completion of the project.
Numerous Cultural Landmarks
Zulu 101 year anniversary parade second line in front of the Autocrat Club on St. Bernard Ave.
Numerous cultural landmarks contribute to the uniqueness of this ward. On St. Bernard Avenue sits – a hall used for business and social functions prior to Hurricane Katrina that still operates today as a space for community events and gatherings. –a ridge of elevated dry land used as a path by Native peoples that later became key to the settlement of New Orleans and the oldest road in the city– is now a hub for small businesses. The heartbeat of the neighborhood is , the local mecca for live music with over 20 venues, bars, and restaurants in a two-block stretch.
Map: A few of the cultural landmarks in the 7th Ward. Click the numbered icons to view a popup with more information about each location.
The Fairgrounds
Portrait of Ella Fitzgerald, Dizzy Gillespie, Ray Brown, Milt (Milton) Jackson, and Timmie Rosenkrantz, New York, NY, 1947.
The 7th Ward is where you will also find The Fairgrounds, which is the third oldest operating thoroughbred racetrack in the U.S. The annual New Orleans Jazz and Heritage Festival is hosted at The Fairgrounds. This acclaimed festival has been graced by legendary artists like Miles Davis, Ella Fitzgerald, Aretha Franklin, and Bob Dylan, and continues to be a major tourist destination.
Right: Aerial image of the Fair Grounds (Google Earth).
The Green Block
Educational event at the Healthy Community Service's "Green Block," a green infrastructure demonstration space in the 7th Ward.
The residents of this neighborhood are committed to preserving its culture and physical spaces. The 7th Ward has recently set the stage as the city’s prototype for concentrated, community-led green infrastructure installations, such as the Healthy Community Services’ “Green Block,” which is working to mitigate flooding and extreme heat with green infrastructure.
Right: Next-door neighbors Eddie Carter and Rollin Garcia Sr. share mirror-image rain gardens (Jeff Strout 2021)
The Homeowners Loan Corporations 1939 residential securities map (a.k.a. redlining map) for New Orleans centered on neighborhood D18, the southern tip of the 7th Ward.
Groundwork New Orleans in the 7th Ward
New Orleans’ 7th Ward was one of the largest neighborhoods in New Orleans to be redlined in the 1930s and consequences of this historical practice are apparent in the climate vulnerabilities the community experiences today.
Flood Vulnerability
The newly-constructed London Avenue Canal permanent pumping station on the northern end of the 7th Ward where the London Avenue Canal runs into Lake Pontchartrain.
The combination of New Orleans’ unique bowl-like topography and the low elevation of the 7th Ward makes it difficult for stormwater to be moved out of the neighborhood quickly, exacerbating residents' vulnerability to flash flooding. Since Hurricane Katrina, New Orleans has rebuilt impressive floodwalls and pumping stations, but with climate change, New Orleans is still threatened by sea level rise and even greater storm surges than the current systems can handle.
Left: The 7th Ward, along with neighboring wards, lies in a closed depression leaving the area at high risk of flooding. This is a map exaggerating the elevation of New Orleans. The white arrows point to a closed contour line indicating a bowl-like landscape.
Extreme Heat
This section of the 7th Ward between St. Bernard and N Broad St. is an extreme surface temperature anomaly with the mean surface temp being between 10 and 25 degrees (F) higher than mean surface temperature for the entire city (95.8 F). Proximity to main thoroughfares, absence of tree canopy and small buildings all contribute to high surface temperatures.
The 7th Ward experiences some of the hottest surface temperatures in the city. In 2021, New Orleans ranked as the worst urban heat island in the United States.[ 7 ] While the entire city is at severe risk of rising temperatures, neighborhoods like the 7th Ward are in greater danger than others. The 7th Ward has significantly less cooling infrastructure such as trees, green space, and tall buildings. Shorter buildings and homes provide less shade and it is very common for these homes to have dark roofs that retain heat. Furthermore, research shows that heat can exacerbate pre-existing conditions like asthma[ 8 ] and diabetes[ 9 ], both of which are prevalent in residents of the 7th Ward neighborhood.[ 10 ]
Left: Surface Temperature Anomaly layer showing areas in the city that have surface temperatures that are significantly higher or lower than normal (mean: 95.8). Surface temperatures were calculated using Landsat 8, 2015-2020, June-August, <20% cloud, no water, using code documented in the following article: Ermida, S.L., Soares, P., Mantas, V., Göttsche, F.-M., Trigo, I.F., 2020.Google Earth Engine open-source code for Land Surface Temperature estimation from the Landsat series. Remote Sensing, 12 (9), 1471.[ 11 ]
Groundwork in the 7th Ward
Youth planting trees in the 7th Ward.
Groundwork New Orleans (GWNO) has been working in the 7th Ward for nearly a decade and remains dedicated to addressing much-needed climate resilience challenges. Recently, GWNO and its community partners transformed a frequently flooded lot on Claiborne Avenue into a bioretention facility that diverts approximately 35,000 gallons of stormwater from flooding the surrounding streets.
Left: Groundwork crew and collaborators pose for a picture on Plant4Peace on Martin Luther King Jr. Day.
Amplifying Voices, Identifying Opportunity
Youth planting tree in the 7th Ward at Plant4Peace on Martin Luther King Jr. Day.
Through Climate Safe Neighborhoods, Groundwork New Orleans will work closely with 7th Ward residents to ensure their voices will be amplified as we identify opportunities for change and co-create solutions to mitigate risks in these neighborhoods. The 7th Ward will serve as a model for other historically-redlined and climate vulnerable neighborhoods of New Orleans. The work starts with the 7th Ward, but GWNO’s hope is that the neighborly energy of this area will ignite and demonstrate the power of strong collaborative efforts that prioritize systems-thinking solutions.
Left: Groundwork New Orleans' newest green infrastructure installation: an enormous bioswale on the corner of Claiborne Avenue and St. Bernard Avenue.
Climate Safe 7th Ward Committee members and local youth in action installing green infrastructure.
Climate Safe 7th Ward Committee
In February 2023, Groundwork New Orleans established the Climate Safe 7th Ward Committee. In partnership with 7th Ward community members and Groundwork NOLA, the Climate Safe 7th Ward Committee is addressing inequitable climate vulnerabilities, including flooding and extreme heat, in the historically redlined New Orleans neighborhood. Through the collection and analysis of local green infrastructure data and the lived experiences of the community, the Climate Safe Committee aims to create a more equitable local green infrastructure system.
Climate Safe 7th Ward Committee members and local youth in action installing green infrastructure.
A screen capture of the New Orleans Green Infrastructure Map.
Groundwork New Orleans has created the first iteration of their New Orleans Green Infrastructure Map. The interactive GIS dashboard intends to show the distribution of green infrastructure and other climate-adaptation interventions in New Orleans. The development of this map is the first of its kind and the final version will provide an understanding of the collective impact that green infrastructure providers have, allow the Climate Safe Committee to identify gaps in coverage and prioritize the most vulnerable block groups within historically redlined neighborhoods.
Empowering the Next Generation: Climate Safe 7th Ward Committee collaborates with local youth to address the impacts of extreme heat and flooding on their communities and cultivate a shared vision for a Climate-Safe future.
Coordinator Profile: Riley Essert
Riley Essert, Groundwork New Orleans' Youth & Environmental Programs Manager.
Growing up in a military family, Riley Essert spent her childhood moving from major city to major city. After graduating from high school in D.C., she moved to Flagstaff, Arizona, a hiker's dreamscape, to begin her undergraduate degree. She “stumbled upon” the brilliance of the world beyond a concrete jungle and realized her deep connection to nature. This change in perspective would shift the direction of her life toward environmental stewardship. She earned a Bachelors of Science from LSU in Natural Resource Ecology & Management and is committed to preserving the incredible ecosystems that sustain us and to bringing the healing power of nature back into cities. She spent additional time studying Ethnobotany in Hawai’i, which solidified her understanding that cultural connections to the environment and land are of the utmost importance in this field of work. She went on to teach youth abroad in Taiwan and worked on an organic farm to establish green infrastructure designs and sustainable practices.
Healing our environment, in turn, heals us.
As the Youth & Environmental Programs Manager for Groundwork New Orleans and a nine-year resident of the city, she serves the community by facilitating educational workshops and engaging with high school students through internship programs. Nationally certified in Green Infrastructure, Riley provides training for youth to earn a GI-focused Clean Water Certificate. She is currently a graduate student at Tulane University in New Orleans and continues her work through the understanding that healing our environment, in turn, heals us.
Get Involved
Tackling climate change in a way that benefits everyone has to be a community-led effort. Join the movement to become part of the solution! Email Riley (riley@groundworknola.org) today to learn more about how you can get involved.
