Siemens’ U.S. and Canada Green City Index evaluated 27 major North American cities and ranked them on more than 30 environmental sustainability criteria across nine dimensions. Denver ranks No. 5 overall, scoring the strongest in energy and environmental governance, where it ranks first.
Denver’s U.S. and Canada Green City Index city portrait:
Denver is the capital of the western US state of Colorado. Located in high plains at the edge of the Rocky Mountains, Denver earned the nickname the “Mile-High City” because of its elevation exactly one mile above sea level. With 610,000 residents living inside the city limits, Denver is considered a mid-population city in the U.S. and Canada Green City Index. The larger metropolitan area is home to some 2.6 million people, and a combination of city and metro-level data are used in the Index. Local economic activity is dominated by transportation, telecommunications, aerospace and manufacturing. The city has a per capita GDP of $49,000, placing it at the top end of the mid-income group of cities in the Index.
Denver is ranked fifth overall in the Index. The city’s strongest categories are energy and environmental governance, where it places first. Its clean and efficient energy policies are among the most robust in the Index, and its environmental governance performance is supported by its green action plan, green management and strong public participation. Denver also ranks among the leaders in most policy areas across the Index owing to the Greenprint Denver Office, established in 2007, which plans and coordinates citywide environmental programs. Denver places in the top ten in the buildings, water, transport and air categories, and is the top performer overall among mid-income cities in the Index.
CO2: 14th, 76 points
Emissions per capita, at 13.2 metric tons of CO2 per year, are below the Index average of 14.5 metric tons. And for every $1 million of GDP that Denver generates, it releases 231 metric tons of CO2 into the atmosphere, versus an Index average of 296 metric tons. A recent report found that carbon emissions from power plants across Colorado declined by 47 percent between 2000 and 2010. The largest utility in the state also has plans to close or retrofit four coal-burning plants, which will have positive ramifications for communities across the state, including Denver. The city also scores well for measuring carbon emissions and for its greenhouse gas reduction strategy.
Green initiatives: One of the first recommendations of the Greenprint Denver Advisory Council in 2007 was to set more ambitious greenhouse gas reduction goals. Denver had a previous target of reducing per capita greenhouse gas emissions 10 percent below 1990 levels by 2012. Taking into account population growth, this per capita target would require an 18 million metric ton reduction of greenhouse gases (16 percent below 1990 levels). But the advisory council called for a more ambitious long-term goal of reducing absolute greenhouse emissions 25 percent from 1990 levels by 2020. The main greenhouse gas reduction areas identified by the advisory council were energy conservation, greater energy efficiency in buildings, renewable energy and carbon offsets.
Energy: First, 86 points
Along with environmental governance, this is Denver’s strongest category in the Index. Electricity consumption per $1 million of GDP is 184 gigajoules, which is nearly half the Index average of 332 gigajoules. Electricity consumption per capita is 38 gigajoules, also below the Index average of 52 gigajoules. The city has taken a proactive approach on managing energy consumption, and is one of only three cities in the Index that scores full marks for clean and efficient energy policies, through its comprehensive Greenprint Denver plan (see “green initiatives” below). In 2010 the Greenprint Denver Office canvassed 15 neighborhoods around the city and implemented at least one “energy action” in 2,500 homes. Actions included measures to improve energy efficiency and reduce weather-related energy loss. Denver’s energy performance also benefits from increasing the amount of locally produced energy, which only a few cities in the Index have managed to achieve. In addition, statewide legislation in Colorado requires that 30% of all electricity produced must come from renewable resources by 2020, and to help meet that target Denver is evaluating around 300 municipal buildings for solar power installations.
Green initiatives: The Greenprint Denver program includes several energy saving initiatives. In 2010 alone, 2,000 LED bulbs in 200 traffic signals were installed with estimated savings of almost $800,000 per year. The city is also in the process of installing solar PV cells with a combined capacity of four megawatts on city buildings and public schools, and has announced it will retrofit the central library for projected annual savings of $150,000 through reduced energy bills. Low-income households are also eligible for assistance to improve energy efficiency and the city also provides them with attic insulation assessments.
Land use: 18th, 53.3 points
This is Denver’s weakest category. The city is marked down for having the smallest amount of green space in the Index as a proportion of its administrative area – just 3 percent versus the Index average of 12 percent. A relatively low population density of 4,000 people per square mile, compared with the average of 8,100 also works against Denver in land use. But the city scores well for its green land use policies and its measures to contain urban sprawl. These include subsidies to promote brownfield regeneration and the protection of its scarce green space from building development.
Green initiatives: Denver has been part of the U.S. Environmental Protection Agency’s Brownfields Program since October 2010. The program targets the 2,000-acre South Platte River area, which contains 33 brownfield sites, coal-fired power plants and railway corridors, and is home to about 88,000 of the city’s low-income residents. With federal assistance the city is identifying and prioritizing brownfield cleanup projects, evaluating potential uses for properties, and, with site owners, conducting environmental assessments. Additionally, in 2006 Denver launched the “Mile High Million” with the goal of planting one million trees by 2025. The city reached a fifth of that target by March 2011.
Buildings: Sixth, 68.8 points
Denver’s strong rank in this category is a reflection of policies aimed at improving the energy efficiency of buildings. The city offers incentives for building retrofits, and distributes information to offices and homes about ways to reduce energy consumption. Strict energy regulation for new buildings has also led to a rise in the number of Leadership in Energy and Environmental Design (LEED)-certified buildings. For every 100,000 people in Denver there are 10.2 LEED-certified buildings, many more than the 6.4 Index average. The one blemish on Denver’s buildings score is its failure to require energy audits, which would help to identify inefficiencies.
Green initiatives: As part of the Greenprint program Denver unveiled its first municipal green building policy: all current and future city buildings have to be LEED certified. To encourage solar power usage in municipal buildings, the city offers minimum 15-year leases to private companies to install, operate and maintain solar energy systems. In return for the lease, energy rates must be lower than those charged by utility companies. Solar systems have been installed in numerous city-owned buildings, the biggest of which is the two-megawatt array at Denver International Airport. A “green roof” installation program for municipal buildings, to cut down energy consumption, is also part of the Greenprint initiative.
Transport: Eighth, 60.7 points
The city’s strong placement in transport is supported by its efforts to make the public transport fleet greener and encourage citizens to walk, cycle or take public transport. Congestion reduction policies are also strong. The city boasts pedestrian-only zones and a well-developed traffic management system to ease traffic flow. The most significant weakness in this category is the lack of public transit supply, even after the city invested $1 billion on improving public transport infrastructure through the Inter-modal Transportation Expansion (T-REX) project, which was completed in 2006. The length of the Denver metropolitan area public transport network remains one of the shortest in the Index at just 0.1 miles per square mile, versus an Index average of 1.1 miles. And, likely a result of the public transport shortfall, Denver’s share of workers using public transit, a bike or walking is also currently relatively low, at 7.4 percent versus an Index average of 13 percent.
Green initiatives: In 1993 Denver became the first US city to launch a Green Fleet program to prioritize fuel efficiency in its public transport fleet. The program, which city officials revised in 2000, calls for a reduction in carbon emissions and fuel expenditures through the adoption of strategies including the purchase of smaller vehicles, encouraging alternative modes of transport, minimizing total vehicle miles, and investing in vehicles that run on alternative fuels. In 2004 Denver launched a pilot program to test clean-burning B20 biodiesel in 60 of the city’s vehicles. Today over 1,000 of the city’s 3,500 vehicles run on biodiesel.
Water: Seventh, 85.6 points
Denver has one of the most efficient water distribution systems in the Index, losing a modest 5 percent of its supply to leaks against the Index average of 13 percent. Water efficiency and treatment policies are also strong. Main water sources are monitored for quality and supply levels, and measures are in place to lower water usage. Denver’s one weakness in the water category is its relatively high consumption. Denver consumes 181 gallons of water per capita per day, which is one of the highest among mid-income cities and well above the Index average of 155 gallons.
Green initiatives: Denver’s new water recycling plant on the South Platte River is the largest in Colorado and work is underway to expand treatment capacity to 45 million gallons a day. The facility supplies recycled water for non-potable uses, such as irrigation for lakes, parks, golf courses and wildlife preserves. And through new irrigations systems already in place, city authorities say they use 28 percent less water in parks than in 2001.
Waste: 17th, 51.9 points
This is one of Denver’s weakest categories, despite the fact that it treats different types of waste, including recyclable, hazardous and industrial. The city also scores well for its waste reduction strategy and for reducing reliance on landfills in favor of more sustainable local waste management practices. Regardless of its efforts to improve recycling (see “green initiatives” below), Denver has one of the lowest recycling rates in the Index, at just 3 percent, versus the 27-city average of 26 percent, which restrains its score.
Green initiatives: In 2005 the city of Denver began a transition to a single-stream recycling system, which allows residents to place all recyclable materials into a single container. Sorting of materials is then conducted at treatment facilities. The city saw a 61 percent increase in recycling rates in the first two years of the single-stream recycling program.
Air: Tenth, 79 points
Denver’s performance in the air category is bolstered by having some of the strongest clean air policies in the Index. Air quality targets have been set and measures are in place to improve air quality, and they have had a positive effect. Denver’s annual sulfur dioxide emissions, at 14 lb per person, fall well below the Index average of 22 lb. But there is still room for improvement. Both particulate matter and nitrogen oxides emissions are above the averages.
Green initiatives: Denver has an anti-idling ordinance limiting idling to five minutes and police have authority to ticket idling vehicles left unattended for any period. In addition, since 2003 the state of Colorado has operated a voluntary mobile vehicle emissions testing program, making it more convenient for motorists to get tested. Vans deployed with special laser-based technology examine vehicles as they drive by and alert drivers to whether they have passed or failed. Drivers who fail the test have the opportunity to retest at a traditional emissions testing facility.
Environmental governance: First, 100 points
Denver ties with New York and Washington, D.C. in this category, earning full points. The performance is underpinned by the Greenprint Denver Office, Denver’s coordinating body for environmental programs across different city agencies. Working alongside the Greenprint Denver Implementation Committee, which helps ensure green measures are integrated throughout city operations, Greenprint Denver is a best-practice model of environmental governance in the Index. A baseline review has been carried out, targets have been set, and evaluation reports are regularly published. There is also easy access to information on the city’s environmental performance and policies, coupled with a central contact point for citizen complaints.
Green initiatives: Greenprint Denver enables public participation in environmental programs through a variety of initiatives, including Green Teams. Green Teams are community-based groups of friends, families and neighbors interested in learning about energy efficiency and carbon emissions reduction, and improving their local environment. The Greenprint Denver office considers these teams catalysts for greater community involvement and provides them with free income-qualified weatherization, subsidized home-energy audits, junk mail reduction, free CFL porch bulbs and trees for planting in neighborhoods. Greenprint’s residential program managers work closely with Green Teams to set tangible goals and decide on the best outreach methods for expanding participation throughout the community, including door-to-door canvassing or neighborhood picnics.
