Linear parks. Rain gardens.
Trails. Green roofs and parking lots.
You may have seen or heard of them, especially if you live in or visit cities such as Boston, Portland, Los Angeles or Chicago.
Often called blue-green infrastructure, they are aimed at resolving issues plaguing many urban areas such as stormwater runoffs causing floods, heat stress, lack of biodiversity and open spaces, and compromised air quality. In addition, their anthropocentric functions such as improved quality of life through recreation is much coveted.
As such, a growing number of cities are leaning on such infrastructure in their urban revitalization plans.
The National Recreation and Park Association (NRPA), a non-profit that works to advance public parks, recreation and conservation, sees the connection between trails, infrastructure and booming property values.
“High-profile parks and trail projects, like the Highline in New York, the 606 in Chicago, and the Atlanta Beltline have spurred billions in private investment, and have raised home values in surrounding neighborhoods,” says Kevin O’Hara, NRPA vice president of urban and government affairs.
He says linear parks and trail projects like the Dequindre Cut in Detroit and the Rose Fitzgerald Kennedy Greenway in Boston draw visitors from across their respective regions, fueling homebuyer interest in those urban neighborhoods.
Below are 5 notable blue green infrastructure projects:
Boston’s Linear Park
Linear parks are typically longer than wider, spread over a few city blocks, and often snake through a city’s heart – giving dwellers a pleasant respite from the surrounding hustle. They often serve as a link in a city’s plan for alternative transportation, or include overlooks, playgrounds, host arts and crafts fairs, or offer a place to picnic in nice weather.
Boston’s Rose Kennedy Greenway is all of that, and more.
Set in the city’s heart, it is essentially a roof garden atop a highway tunnel. It originated from the city’s much talked about “Big Dig,” a massive construction project that relocated an elevated highway and built underground tunnels instead. The 1.5-mile Greenway opened in 2008 and includes trees, plants, lawns, water features in the summer, and one of the largest free public Wi-Fi networks in the city.
It caters not just to office goers looking for a place to sit down for lunch (it has an enviable collection of food trucks), but also children – with a carousel and ziplines, and hosts an array of music, food, and art events throughout the year.
Portland’s Rain Gardens
Rain gardens can be installed in almost any unpaved space.
They are shallow, vegetated basins that collect and absorb runoff from rooftops, sidewalks, and streets. This practice mimics natural hydrology by infiltrating, evaporating and transpiring stormwater runoff.
Portland has been a pioneer in installing such basins. In 1991, the city began a $1.4-billion combined sewer overflow (CSO) program to prevent sewage overflows during heavy rains that commonly occurs in the Willamette River and northern Columbia basins.
Now, those overflows are rare.
The CSO program was fully funded by ratepayers and completed in 2011. The project comprised construction of sumps and big pipes and tunnels underground to expand the system’s capacity. Homeowners also took action by disconnecting downspouts and letting rain gardens absorb storm-water on their private property.
Today, bigger cities such as Philadelphia, Washington DC, and New York City are following Portland’s example by building rain gardens that collect storm water and effectively combat flooding and contamination by runoff into its lakes and rivers.
LA’s Green Street
Called the Rolls-Royce of LA’s Green Street initiative, Elmer Avenue has dramatically transformed in the past few years.
From having no sidewalks, street lights or even storm drains leading to frequent flooding, the street now has become a showcase of environmental friendly features – thanks to a federal bureau, a state agency, handful of city agencies and nonprofit groups.
With the co-operation of all 24 homes on the street block who donated a portion of their front yard, the street got new curving sidewalks, solar street lamps and gutters with curb breaks feeding rainwater from the street into bioswales.
The bioswales could capture majority of rain water during storms – water that would otherwise cause flooding or be diverted to LA’s storm drain system out to the Pacific Ocean instead of being collected in the underground aquifer.
The 37 acres drained by the Elmer Avenue Retrofit Project will produce an estimated 16 acre-feet of rain runoff every year, according to the Watershed Council, “enough water to sustain the residents of the street.”.
New York City’s High Line
Built on an abandoned railroad spur, New York’s High Line has become a huge magnet for tourists and city dwellers alike.
The 1.45-mile-long line is an elevated linear park, greenway, and rail trail.
It used to be a former New York Central Railroad spur on the west side of Manhattan. Because of declining use, the freight line was virtually abandoned in the 1980s.
Repurposing this piece of land began in 2006, with the first phase opening in 2009 and the final in 2014. The project has kick-started real estate development in adjacent neighborhoods and boosted property prices along the route.
Today, the High Line is a major city attraction.
It features wildflowers, greenery and outdoor art installations in addition to awesome views of New York’s skyline. Running a span of more than 15 city blocks, it covers the length from Hudson Yards to the northern edge of Chelsea with several points along the way to get in and out of the park. Restaurants and cafes have sprung up along the route to cater to park goers.
Chicago’s green roofs
Chicago may be known for its skyscrapers, but it’s also getting a reputation for another type of infrastructure: green roofs.
It has more than 500 green roofs, covering 5.56 million square feet. They sit atop its City Hall, Target and Apple stores, even a McDonalds burger joint. Buoyed by the city’s Green Roof Grant Program, they have sprung up all across the city.
Green roofs are covered with vegetation that enable rainfall infiltration and evapotranspiration of stored water. They are particularly cost-effective in dense urban areas such as Chicago where land values are high, including on large industrial or office buildings, where stormwater management costs are likely to be high. Green roofs also cool down buildings during peak summer months, saving on energy costs.
For example, Chicago began construction of a 38,800 square foot green roof atop its City Hall in April 2000. It was completed at the end of 2001 at a cost $2.5 million, funded by a settlement with ComEd. According to estimates, the green roof saves $5,000 a year on utility bills.
Note: Michael Keating, who produces content for American City & County and the GPN web site, contributed to this report.