State and Local Policy Database

Community-Wide Summary

The clustering of unvegetated, impermeable surfaces in cities leads to a phenomenon known as the urban heat island effect. Urban heat islands increase the demand for cooling energy, and also result in negative environmental and public health impacts. Cities can take steps to mitigate the urban heat island effect through policies and programs including those to increase city-wide vegetation and the presence of “cool” surfaces such as reflective roofs and pavements.

This sub-category includes information on two topics: existence of programs, goals, or incentives related to urban heat islands; and the existence of policies or mandates, such as cool-rood requirements or tree-planting ordinances, that enable continual implementation of mitigation strategies.

Arlington does not have an urban heat island mitigation goal. Nevertheless, Arlington has a stormwater management ordinance in place for the protection of the Chesapeake Bay. Arlington also has a tree ordinance in place that protects existing trees. 

Last updated: May 2017

Atlanta recently entered an agreement with Trees Atlanta, a local nonprofit, to plant 4,000 15 gallon trees between 2015 and 2017.

The city has adopted a transfer of development rights policy which provides development bonuses for those real estate developers that permanently protect greenspace. The city’s conservation subdivision ordinance encourages the permanent protection of land alongside dense residential development patterns. The city has also adopted a private tree protection ordinance, but it has not adopted policies that require or incentivize the use of low impact development (LID) techniques.

Last updated: April 2017

The city has established individual urban tree canopy cover goals for each neighborhood throughout the city. The city is targeting tree planting projects using these targets.

In Austin, development bonuses are available for private development projects that incorporate green roofs into new projects or that permanently preserve open space. Austin also adopted the 2012 International Energy Conservation Code which requires cool roofs on buildings. Exceptions to this requirement are granted for buildings with vegetative roofs, roof top pools, or permanently integrated solar panels on a roof surface. The city’s tree ordinance protects trees on private land designated as heritage trees and trees with a substantial diameter at breast height.

Last updated: April 2017

The Baltimore Sustainability Plan includes an urban heat island mitigation goal to double the city's tree canopy by 2037.

Baltimore has adopted several policies and programs which mitigate the city’s urban heat island effect. The Baltimore Energy Initiative provides grants for cool roof installations through the city. In carrying out its obligations under the Maryland Forest Conservation Act, the city has adopted a land conservation policy that requires sites undergoing development to preserve land with at 20,000 square feet of forest, steep slopes, streams, and wetlands. Baltimore’s Variance Policy for Specimen Tree Removal protects trees that are at least 20 inches diameter at breast height. The TransForm Baltimore Zoning Code provides development bonuses for the permanent preservation of open space.

Last updated: January 2017

Birmingham has not adopted urban heat island mitigation goals.

Nevertheless, the city has allowed for conservation subdivisions as part of its Zoning Ordinance that encourage the permanent protection of land alongside dense residential development patterns. The city has not adopted a private tree protection ordinance or policies that require or incentivize conservation of private land.

Last updated: January 2017

Mayor Thomas Menino created the Grow Boston Greener (now Greenovate Boston) program with the goal of planting 100,000 new trees in Boston by 2020 and increasing the tree canopy to 35%.

We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land. The city does not have a private tree protection ordinance.

Last updated: April 2017

Boulder has an urban forestry program whose activities include a ten-year pruning rotation, planting trees, and a public education campaign on proper tree selection and maintenance of public trees.  Also, the city has a tree planting requirement for new and re-developments and the Boulder Valley Comprehensive Plan has policies to mitigate the heat island effect, including a strategy to promote environmentally sensitive urban design.

Last updated: October 2015

Burlington has not enacted specific heat island policies but the city is working to increase green space and plant trees as a heat mitigation strategy.  The city is also creating a Parks Master Plan to guide future maintenance, development, and resiliency of city parks.

Last updated: October 2015

Carrboro has begun to address urban heat islands through the town’s Land Use Ordinance, which limits the impacts from new development.  The most important provision is a 40% open space requirement for residential development.  Since 2010, Carrboro has maintained a 58% tree canopy.

Last updated: April 2014

Charlotte’s City Council formally adopted a goal to reach 50% urban tree canopy cover in the city by 2050. The city works to implement this goal through the work of Trees Charlotte. The city has also adopted a private tree protection ordinance. We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land.

Last updated: January 2017

Charlottesville developed an Urban Forest Management Plan to ensure city trees are appropriately managed and earned a “Tree City USA” designation by the National Arbor Day Foundation for its efforts.  The city also has begun to address urban heat islands through policies.  The city has adopted an incentive to encourage the installation of green roofs on commercial and residential properties. 

Last updated: October 2015

The city’s Climate Action Plan has a goal to increase rooftop gardens to a total of 6,000 buildings citywide by 2020 and to plant an estimated 1 million trees by 2020.

Per Chicago’s Sustainable Development Policy, new construction projects are required to integrate low impact development measures or restore natural lands. The city's policy also provides expedited green permits for construction involving a green roof, rainwater harvesting, or a similar measure. The Chicago Energy Efficiency Conservation Code requires new low-sloped roofs to have a minimum 3-year reflectance of 0.5 and medium sloped roofs to have a reflectance of 0.15. Chicago was one of the first cities to require cool roof technologies, having integrated requirements into the city’s energy efficiency code as early as 2001. Chicago has not adopted a private tree protection ordinance.

Last updated: April 2017

The city has not adopted have any goals to directly address temperature increases resulting from the urban heat island effect. The city is indirectly addressing its urban heat island through its goal to increase the acreage of high-quality green space 10% by 2020 through parks and rooftop gardens. The regional Taking Root initiative also has a goal to plant 2 million trees by 2020.

Green roof loans are provided through a joint program backed by the Ohio Environmental Protection Agency, Metropolitan Sewer District of Greater Cincinnati, and the Cincinnati Office of Environmental Quality. The Cincinnati Zoning Code also allows for cluster housing zoning that encourage the permanent protection of land alongside dense residential development patterns.. The city has not adopted a private tree protection ordinance.

Last updated: January 2017

The Cleveland Tree Plan was adopted by the Cleveland Planning Commission in March 2016 with an urban heat island mitigation goal to increase urban tree canopy coverage in the city to 40% of land area by 2040.

The city participates in the Northeast Ohio Regional Sewer District’s Green Infrastructure Grant Program which has provided grants for incorporating low impact development techniques in site design. The city has not adopted a private tree protection ordinance or policies that require or incentivize the conservation of private land.

Last updated: January 2017

Green Memo III established an urban heat island mitigation goal to plant 300,000 trees by 2020 and increase the city’s urban tree canopy from 22% to 27%.

We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land. The city has not adopted a private tree protection ordinance.

Last updated: April 2017

While the city’s comprehensive plan forwardDallas! does include a broad goal to preserve and increase tree canopy, but the city has not adopted a specific quantitative urban heat island mitigation goal.

Dallas recently adopted the Green Building Program Ordinance which encourages the construction of sustainable buildings through two implementation phases. The first phase is focused on encouraging energy efficiency, water conservation and reduction of the heat island effect through cool roofs. The second phase will expand to implement a comprehensive green building standard for all new construction. Newly proposed commercial projects with less than 50,000 square feet of floor area will be required to meet energy efficiency, water conservation, cool roof, and outdoor lighting requirements.

The city has adopted a private tree protection ordinance, but it does not apply to single family residential land. The city has not adopted policies that require or incentivize conservation of private land.

Last updated: April 2017

As part of its Game Plan, Denver adopted a goal to have 18% urban tree canopy coverage in the city by 2025. Denver’s energy loan program, implemented through the Denver Energy Challenge, provides low-interest financing for cool roofs. The city has also passed a private tree protection ordinance. We did not find information on any policies that require or incentivize conservation of private land.

Last updated: April 2017

We did not find information on whether the city has a quantitative goal or active policies or programs to mitigate the urban heat island effect.

Last updated: January 2017

We did not find information on programs or policies to mitigate urban heat islands in Dubuque.

Last updated: October 2013

The city has not adopted an urban heat island mitigation goal.

The city does grant development bonuses for permanent protection of area wetlands as part of its transfer of development rights policy. The city has not adopted a private tree protection ordinance. We did not find information on any policies that require or incentivize low impact development (LID).

Last updated: January 2017

The city adopted an urban tree canopy coverage goal of 30% through Ordinance 18615-05-2009. The ordinance lays out both private tree preservation and planting requirements for the city.

We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land.  

Last updated: January 2017

The City of Hartford and KNOX, a local nonprofit, commissioned American Forests to create Hartford’s Urban Tree Canopy Assessment & Planting Plan. The plan includes an urban heat island mitigation goal to plant 20,000 trees in 20 years between 2010 and 2030, increasing the city's tree canopy by 10%.

The city has adopted a private tree protection ordinance for trees with a diameter at breast height of at least 13 inches. We did not find information on any policies that require or incentivize with low impact development (LID) or conservation of private land.

Last updated: January 2017

Million Trees + Houston established a three- to five-year goal to plant one million trees.

A cool roof policy is included in the city’s Energy Conservation Code. The code requires cool roofs on all commercial buildings. Residential buildings with low sloped roofs must have minimum solar reflectance of 0.70 and thermal emittance of 0.75.

The city has also provides development incentives for preservation of open space. The city has not adopted a private tree protections ordinance.

Last updated: January 2017

The city has not adopted urban heat island mitigation goals.

The city has also allowed for conservation subdivisions as part of its Consolidated Zoning / Subdivision Ordinance that encourage the permanent protection of land alongside dense residential development patterns. The city also requires that new developments be rated on a Green Factor Scale that assigns points for the of various low impact development techniques in site design.

Last updated: January 2017

The city has not adopted urban heat island mitigation goals.

The city has adopted a private tree protection ordinance. We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land.

Last updated: January 2017

The city’s Climate Protection Plan contains an urban heat island mitigation goal to increase urban tree canopy to 40% of the city’s land cover. The city does allow for open space and conservation developments that encourage the permanent protection of land alongside dense residential development patterns. The city has not adopted a private tree protection ordinance. We did not find information on any policies that require or incentivize low impact development (LID).

Last updated: April 2017

Knoxville has a Tree Protection Ordinance and a tree management plan to increase the tree canopy and specific diversification.  Also, the Knoxville Utilities Board is installing cool roofs.

Last updated: October 2015

The city passed the Urban Forestry Initiative in 2008 (R-26-2008) to improve air quality, reduce the urban heat island effect, and increase quality of life in terms of shade, beauty, and privacy for Las Vegas residents. The initiative includes an urban heat island mitigation goal to increase urban tree canopy coverage to 20% by 2035.

The city requires all non-residential developments greater than one acre in size to use low impact development techniques in site design. The city has not adopted a private tree protection ordinance or policies that require or incentivize conservation of private land.

Last updated: January 2017

Lawrence does not have programs or policies in place to mitigate urban heat islands.

Last updated: October 2013

The city’s Sustainable City pLAn has set a goal to reduce the local urban-rural temperature differential by at least 1.7 degrees Fahrenheit by 2025 and 3 degrees Fahrenheit by 2035. The city adopted this target because average temperatures in Los Angeles are nearly six degrees hotter than surrounding areas.

The city has adopted requirements for buildings to include cool roofs and low impact development techniques in site design. The city also awards development bonuses for permanent protection of open space through a transfer of development right program. The city has not adopted a private tree protection ordinance.

Last updated: April 2017

The Louisville Urban Tree Canopy Assessment adopted an urban heat island mitigation goal to reach 45% urban tree canopy cover across the city.

The city’s Land Development Code allows for conservation subdivisions that encourage the permanent protection of land alongside dense residential development patterns. The city is currently in the process of developing an incentives program to encourage the use of low impact development techniques in site design.

Last updated: April 2017

The City of Madison installs green infrastructure, including rain gardens, and trees on medians and terraces during street construction.  Madison also has a policy in place to protect mature trees and encourages green roofs on private development. 

Last updated: October 2013

In the Sustainable Shelby Plan, Memphis and Shelby County have stated goals to develop an urban forestry program, hire a fulltime urban forester to audit the current system, develop a tree master plan, and create an initiative to plant 5,000 street trees per year. In late 2014, Memphis completed a regional tree canopy study with the University of Memphis and the Wolf River Conservancy. In 2015, the city also adopted the regional Greenprint plan that establishes a unified vision for a region-wide network of greenspaces.

We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land. The city does not have a private tree protection ordinance.

Last updated: January 2017

The city’s Tree Master Plan calls for a 30% increase in urban tree canopy by 2020. Miami has adopted a private tree protection ordinance. Miami’s Code 21 includes requirements for cool roofs on buildings and provides building height bonuses for developers that permanently protect area wetland and open space. The city has not adopted policies that require or incentivize the use of low impact development (LID) in site design.

Last updated: January 2017

ReFresh Milwaukee contains an urban heat island mitigation goal to double tree canopy coverage in Milwaukee to 40% by 2023.

The city helps fund the Metropolitan Milwaukee Sewer District’s Green Infrastructure Funding Program that provides incentives for the use of low impact development techniques in site design. Milwaukee has not adopted a private tree protection ordinance or policies that require or incentivize conservation of private land.

Last updated: April 2017

The Minneapolis City Council adopted two quantitative urban heat island mitigation goals: Maintain the city’s 31% tree canopy level through 2015, and plant at least 6,000 trees annually on public land by 2015.

Minneapolis has adopted land conservation requirements which mandate that real estate developers permanently preserve open space if a residential development results in a net increase of residential dwellings for the city. The Minneapolis Stormwater Utility Fee Credit System allows credits for various low impact development practices such as green roofs, vegetated swales and rain gardens.  The city has not adopted a private tree protection ordinance.

Last updated: April 2017

Nashville’s Urban Forestry Master Plan has includes quantitative urban tree canopy goals for different neighborhoods within the city. The city has adopted a private tree protection ordinance. The city requires that sites undergoing construction use low impact development measures in accordance with the city’s Low Impact Development Manual. The city also allows for cluster subdivisions that encourage the permanent protection of land alongside dense residential development patterns.

Last updated: January 2017

The city is in the process of adopting an urban heat island mitigation goal.

The New Orleans Comprehensive Zoning Ordinance contains numerous requirements and incentives that mitigate the urban heat island effect. The city’s zoning code requires the use of low impact development techniques in site design, protects private trees on sites undergoing development, and encourages the permanent protection of land alongside dense residential development patterns.

Last updated: April 2017

New York City’s One City Built to Last plan has a goal to coat 10 million square feet of rooftops white by 2025 to mitigate the effects of the city’s urban heat island. MillionTreesNYC is a city-wide public-private program to assist with the goal of planting and caring for one million new trees across the city’s five boroughs over the next decade.

The city installs cool roofs at no cost to qualifying building owners through the NYC CoolRoofs Program. The city also provides cash and property tax incentives to property owners that agree to permanently protect undeveloped land through the city’s Conservation Easement Program. The city does not have a private tree protection ordinance.

Last updated: April 2017

Oakland does not have an urban heat island mitigation goal. Title 16 of Oakland’s code and Oakland’s Creek Protection, Stormwater Management & Discharge Control Ordinance, addreses stormwater management, tree protection, cool roofs, and LID (Low Impact Development) standards.  

Updated: April 2017

We did not find information on whether the city has a quantitative goal, programs, or policies with the aim of mitigating the urban heat island effect.

Last updated: January 2017

The Green Works Plan includes an urban heat island mitigation goal to increase the city urban tree canopy coverage to 27% by 2018 and 40% by 2040.

Orlando provides development bonuses for buildings that install green roofs. The city allows cluster subdivision developments that encourage the permanent protection of land alongside dense residential development patterns. The city has adopted a private tree protection ordinance.

Last updated: January 2017

Park City does not have programs or policies in place to mitigate urban heat islands.

Last updated: October 2013

The Greenworks plan has an urban heat island mitigation goal to increase tree canopy by 30% in the city by 2025.

The city passed Bill 090923 requiring certain new buildings to have highly reflective cool roofs. The city also provides building height bonuses in exchange for preservation of open space. The city has not adopted a private tree protection ordinance.

Last updated: April 2017

The city has adopted a Tree and Shade Master Plan that includes an urban heat island mitigation goal to increase the city’s urban tree canopy to 25% of land area by 2030.

We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land. The city does not have a private tree protection ordinance.

Last updated: April 2017

Pittsburgh’s Urban Forest Master Plan has an urban heat island mitigation goal to increase urban tree canopy cover to 60% by 2032.

The city requires development projects receiving more than $1 million in public funds (or developments not receiving public funds but that are greater than 10,000 square feet) to incorporate low impact development practices in their site design and construction. The city does not have a private tree protection ordinance or policies that require or incentivize conservation of private land.

Last updated: April 2017 

Portland has urban heat island mitigation goals in its 2015 Climate Action Plan to reduce the city’s impervious surface area by 600 acres and increase the urban tree canopy to cover at least one-third of the city by 2030.

The floor-to-area bonus ratio policy for central city buildings offers a developer bonus for buildings which incorporate an eco-roof. The city has also adopted a private tree protection ordinance. The city has not adopted policies that require or incentivize conservation of private land.

Last updated: April 2017

Sustainable Providence establishes the city’s goal to increase Providence’s tree canopy from 23% to 30% and places priority on planting trees in low canopy neighborhoods.

The city has adopted a development incentives policy that awards building height bonuses in the downtown area to real estate developers that preserve open space. The city does not have a private tree protection ordinance or policies that require or incentivize low impact development (LID) techniques.

Last updated: January 2017 

The city has not adopted urban heat island mitigation goals.

The city has adopted a private tree protection ordinance. The city has also allowed for conservation subdivisions as part of its Unified Development Ordinance that encourages the permanent protection of land alongside dense residential development patterns. Raleigh has not adopted policies that require or incentivize low impact development (LID) techniques.

Last updated: January 2017

Richmond has not adopted urban heat island mitigation goals.

The city has passed Ordinance 2012-201-199 that fast tracks building and related permits for development projects that include a green roof. The city has not adopted a private tree protection ordinance or policies that require or incentivize conservation of private land

Last updated: April 2017

Riverside has adopted an urban heat island mitigation goal in the city’s Green Action Plan to increase the city's urban forest by annually planting at least 1,000 trees in city parks and right-of-way’s and 3,000 trees on private property.

Riverside's municipal utility provides rebates for cool roof coatings on residential and commercial buildings. The city has not adopted a private tree protection ordinance or policies that require or incentivize conservation of private land.

Last updated: April 2017

Integrated into the city’s 2035 General Plan, the city’s Climate Action Plan identifies urban heat island mitigation strategies and actions. These goals include incorporating cool pavement into regular infrastructure maintenance and planting 1,000 new trees annually until achieving 35% urban tree canopy.

The city’s municipal utility provides cool roof incentives, and the city provides development bonuses for installing a green roof on a building. The city has also adopted a private tree protection ordinance.

Last updated: January 2017

Salt Lake City’s Urban Forestry Program aims to increase the number of trees community-wide by 2% annually.

The city does allow for cottage development zoning within its form based zoning code that encourage the permanent protection of land alongside dense residential development patterns. Salt Lake City has also adopted a private tree protection ordinance. We did not find information on any policies that require or incentivize low impact development (LID).

Last updated: January 2017

The SA Tomorrow sustainability plan includes an urban heat island mitigation goal to increase urban tree canopy cover from 30% to 40% of city land.

The city has passed a conservation subdivision ordinance that encourages the permanent protection of land alongside dense residential development patterns. The city also provides development bonuses for permanent preservation of open space. San Antonio recently passed a private tree preservation ordinance.

Last updated: April 2017

The city’s Climate Action Plan has an urban heat island mitigation goal to increase urban tree canopy coverage to 15% of the city’s land by 2020 and 35% of the city’s land by 2035.

We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land. The city does not have a private tree protection ordinance.

Last updated: April 2017

The city’s Climate Action Strategy includes a goal of increasing the tree canopy of the urban forest to 25% of city land area by 2030.

The city has adopted a Better Roofs Ordinance which requires new residential and commercial buildings to have either green roofs or roofs with solar panels. The city has not adopted a private tree protection ordinance or policies that require or incentivize conservation of private land.

Last updated: April 2017

The city’s Green Vision plan includes a goal to plant 100,000 new trees by 2022.

The city has adopted a private tree protection ordinance. We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land.

Last updated: April 2017

Seattle’s 2013 Urban Forest Stewardship Plan includes a goal to increase the city’s urban tree canopy from 23% land cover to 30% by 2037.

The city’s 2016 Stormwater Code Ordinance includes requirements that private lands incorporate low impact development techniques into site design. The city allows for cottage residential zoning that encourages the protection of land alongside dense residential development patterns. The city also provides development bonuses for permanent protection of open space as part of a transfer of development rights policy. The city has adopted a private tree protection ordinance.

Last updated: April 2017

The city’s Sustainability Action Agenda has an urban heat island mitigation goal to increase the number of trees planted by 16,000 or achieve an additional 15% of urban tree canopy cover.

We did not find information on any policies that require or incentivize low impact development (LID) or conservation of private land. The city does not have a private tree protection ordinance.

Last updated: January 2017

The city’s Urban Forest Management Plan includes a goal of no net loss of tree canopy cover for the entire city and has also established individual neighborhood tree canopy goals for each of the city’s municipal districts.

The city has adopted a private tree protection ordinance. The city also allows for cluster residential subdivision zoning that permanently protect land alongside dense residential development patterns as part of its Site Plan Zoning District Procedures Ordinance. The city has not adopted policies that require or incentive the use of low impact development (LID) techniques.

Last updated: January 2017

Virginia Beach has adopted an urban heat island mitigation goal to achieve 45% urban tree canopy cover citywide by 2023 in its Urban Forest Management Plan.

The city provides tax incentives for the permanent preservation of open space and forest. The city has not adopted a private tree protection ordinance adopted policies that require or incentivize the use of low impact development (LID) techniques.

Last updated: January 2017

The Sustainable DC Plan includes an urban heat island mitigation goal to increase the urban tree canopy to 40% of land area. The city also has a goal to increase wetland acreage by the Anacostia and Potomac rivers by 50%.

Washington, DC requires real estate development projects to use low impact development techniques in site design to achieve a required green area ratio. The city has also adopted a private tree protection ordinance. The city does not have policies that require or incentivize conservation of private land.

Last updated: April 2017