Alana Miller, a policy analyst at the Frontier Group, wrote this guest commentary.

Denver is one of the nation’s fastest growing cities. People are drawn here from around the country by the quality of life, proximity to the mountains and 300 days of sunshine a year. 

The influx to Colorado is nothing new. But it raises a difficult question: If hundreds of thousands of people flock to a place because of its access to nature, how do you preserve the natural beauty that brought them there in the first place?

A recent Denver Post series raised some of these questions, arguing that development in Denver has paved over green space so that “nearly half the land in Denver’s city limits is now paved or built over,” (excluding undeveloped land around the airport). As one article notes, replacing green space with pavement increases runoff, since stormwater cannot filter into the ground and instead flows directly into local rivers and ponds, bringing pollutants with it and increasing the risk of flooding.

The article posits that “Denver’s elected leaders and developers over the past 20 years drove this shift toward high-rise towers, yard-devouring duplexes and shopping plazas,” replacing green space with “an increasingly dense format that has enabled population growth.”

There’s something important missing in the Post’s account of Denver’s growth, however. The city’s pavement problem isn’t because of a growing population of people. It’s because of a growing population of cars.

The primary threat to green space in and around Denver is not skyscrapers going up in downtown or apartments constructed to accommodate new people. It’s the roads, driveways and – perhaps most egregiously – the parking lots we’ve built to accommodate more cars.

Of the 37,800 acres of land in Denver that is impervious (covered in pavement or buildings), 60 percent is infrastructure to support cars, according to data presented by the Post. Space just for parking cars accounts for nearly a quarter of all of Denver’s paved areas. (The city’s parking lots have even earned notoriety nationally, “winning” Streetsblog USA’s annual Parking Madness Tournament in 2017 for the vast expanse of parking surrounding Pepsi Center in downtown.) To put all that parking pavement in perspective, here is a visualization of the land we’ve devoted to parking in downtown Denver.

Many recent new developments downtown have been built on areas that were already paved. Parking lots and low-density industrial lots have been turned into apartments and condos, offering easy access to regional rail, the free buses running on 16^th, 18^th and 19^th streets, as well as other bus and light rail service throughout the city. New bike lanes, along with shared bikes and scooters, offer even more non-vehicular options for people living in or near downtown. And amenities such as the downtown King Soopers and new Whole Foods, as well as the compact Target on 16^th Street Mall mean that more people can meet their daily needs without using a car. For people who choose to own a car, much of the new parking is located underground, freeing up ground-level space.

Increasing the number of people in Denver who don’t need to use a car for every trip means reducing the pressure to build car-oriented developments farther out that create vast demand for roads, parking lots and pavement. 

Auto-dependent sprawl requires residents to drive long distances to live their daily lives and perpetuates the allocation of paved space to cars in the form of new and expanded roads and parking lots. Consider the development of Green Valley Ranch, within Denver’s limits, which looks “greener” than downtown. But while it may boast more natural space and less impervious surface area than downtown, it paved over agricultural land (rather than already-developed city land) and required new roads. It also lacks amenities such as grocery stores, which forces residents to drive miles to Stapleton or Aurora, and park their cars in massive parking lots while they shop, to meet their daily needs.

For decades, developments like Green Valley Ranch have been the norm in the Denver metro region. And the loss of natural land to sprawl in the broader Denver region far exceeds the amount of open space lost within Denver itself.

Between 2001 and 2011, according to data from the Center for American Progress, Denver County lost 42 acres of land for every 1,000 new residents it added. However, to the north, Adams County lost more than doubled the amount of natural area to accommodate the same number of people – 92 acres per 1,000 new residents, while Douglas County, to the south, lost nearly 140 acres per 1,000 people, three times Denver’s rate. In Jefferson County, the gateway to the Rocky Mountains, every 1,000 new residents consumed 470 acres – ten times more than in Denver. It may seem counterintuitive, but adding more population density in the city of Denver, as opposed to continuing suburban sprawl, can help save our green space.

Favoring sprawl over density consumes more land and makes it harder for us to reach our climate goals. Nearly 70 percent of people working in Denver drive solo to work. In 2017, Denver’s mayor set ambitious goals to reduce that to 50 percent by 2030, while doubling the number of people taking transit, biking and walking. It will be hard, if not impossible, to meet these goals without enabling people to live closer to work and amenities, as well as reallocating some of our abundant road space to transit, bikes and pedestrians.

When it comes to accommodating new arrivals to Colorado, “high-rise towers, yard-devouring duplexes and shopping plazas” are not all built alike. Repurposing under-utilized asphalt in surface parking lots downtown in favor of apartments, offices, stores and amenities helps accommodate the Denver region’s population growth while preserving green space that could otherwise be bulldozed in favor of sprawling development on the city’s fringes and in nearby towns.

People are moving to Denver, whether you embrace our new neighbors or long for how things used to be. Importantly, this provides us with an opportunity to think about the type of city we’re building for the future. Access to green space in cities is critical and Denver would do well to expand and improve parkland, as it has along the Platte River. As we build, we should make sure every new development reduces runoff by using green infrastructure. But ultimately, the environment will be best served by encouraging people to live closer together and closer to the things they need, rather than forcing them to live far away. Compact development in Denver, done thoughtfully, can help make that a reality.