Emerald revolution?

Such a rare opportunity exists here in Boston, in the scarred corridors that will be left behind when the elevated Central Artery is finally torn down in the mother of all capital improvement projects, the Big Dig. Miles of highway will be plunged underground, unshackling large blocks of cityscape in the North End, Chinatown, and East Boston. The city wants at least 75 percent of this freed land downtown to be used for public parks, playing fields, community gardens, and the like. "The more open space we can have in this city, the better off we are," says Mayor Thomas Menino.

Few would disagree with the mayor. After all, what's not to like about urban green space? It's like coming out in favor of warm weather and blue skies. Some of this city's oldest and most famous landmarks -- Boston Common, the Public Garden, and other parks on the Emerald Necklace -- are green spaces. The same is true of other cities throughout the country. From the Charles River to Central Park to the Mall in Washington, DC, our most prized urban environments are often those that stand in contrast to hulking skyscrapers and swaths of cement.

With the space that will be freed by the Central Artery/Tunnel project -- together with a number of other ambitious open-space initiatives in neighborhoods from East Boston to the South Shore -- Boston has a chance to transform the city's physical character. (See "Boston's emerald future," right.) Urban neighborhoods that were ripped apart by the artery's steel-and-concrete platforms can be rejoined and reinvigorated, and the city's historic link to its waterfront can be reestablished. Indeed, an infusion of urban green space can enhance Boston's quality of life in a way that no building -- or tax cut -- ever could.

And that's what makes those involved in Boston's green-space planning both hopeful and fearful. How do they capitalize on the excitement and good will surrounding these proposals without letting the process devolve into a shouting match?

The open-space agenda now under consideration in Boston is far-reaching and ambitious, touching almost every corner of the city. Three decades from now, flying over Boston in an airplane, you could find yourself looking down at a landscape that has been dramatically changed. You might see a long, narrow stretch of green running above the depressed Central Artery; to the east, a public harbor walk might trace the city's shoreline. Sailboats and ferries might navigate among a chain of inviting harbor islands. A series of trails and parks might dot Charlestown and East Boston; to the south, you could see a majestic greenway muscling along from the Blue Hills to South Boston.

Imagine a city where it's possible to bicycle downtown from the South Shore, barely stopping for a street light. Or to take a walk through the Financial District, pausing to rest in any number of grassy parks. Imagine family trips to an elaborate downtown horticultural garden, followed by a stroll along a waterfront whose open, expansive views are not much different than they were a century ago. Consider the prospect of taking a ferry to a newly landscaped city island, or catching a ball game at a plush East Boston softball diamond. Now take all of these possibilities, add them to today's impressive roster of city parks -- places like the Public Garden, Arnold Arboretum, and Franklin Park -- and link them together. Imagine a reconnected Boston.

"I don't think people can even begin to visualize the impact of what this will be like," says Justine Liff, commissioner of the Boston Parks and Recreation Department. "These open spaces will define the quality of life in Boston more than anything else the city does."

But the ambitious planning process could go awry. In the absence of a single, powerful vision, even the most promising green spaces can see their potential diminished by conflicting interests, ideas, and egos -- not to mention poor maintenance.

Consider the park in the Back Bay Fens. Olmsted's first contribution to the Emerald Necklace, it began as a near-wild slice of marshland that uniquely served the needs of its surrounding neighborhood. But in subsequent years, the involvement of additional parties and designers, developments such as the damming of the Charles River (which removed salt water from the area), and the Fens' dismemberment by roads changed the park to the point where it bears little resemblance to Olmsted's original 1879 design. The park remains a popular gathering place, but it is an aesthetic failure, a well-intentioned but incongruous hodgepodge of uses and details. There are memorials next to rose gardens next to footpaths and bridges and unkempt thickets of brush. Any chance of serenity is punctured by a gallimaufry of playing fields -- basketball courts, softball diamonds, and a running loop. In her book Frederick Law Olmsted and the Boston Park System, Cynthia Zaitzevsky refers to the latter-day Back Bay Fens as "a rather peculiar collection of spaces that appear to be connected entirely by accident."

This kind of mistake isn't unusual. When a public green space is created, there's an understandable temptation to be overly inclusive, to meet every neighborhood desire. Although these desires often deserve to be accommodated -- playing fields, tot lots, and other outdoor amenities are important to many people -- it's also essential to consider the spirit of the park as a whole. Too often, what ends up missing is the peace that Olmsted argued was essential to refresh city residents.

"There's a lot of talk nowadays about a sense of place," says Eugenie Beal, president of the Boston Natural Areas Fund, which contributes to a number of the city's green-space initiatives. "That sense of place makes people more comfortable."

The roots of the Boston park system stretch back to the mid-19th century, when local leaders across the country, witnessing the growing size and density of the nation's cities, recognized the need for urban dwellers to find solace from the rush of metropolitan life. Here in Boston, of course, several substantial green spaces were already in place -- Boston Common, built in 1634 (the nation's oldest park), and the Public Garden, created in 1837, which featured an array of Victorian flower beds and pathways.

But the blossoming of the city's park system didn't begin in earnest until the late 1800s, when the development of the Back Bay was well under way and the need for green space became more pressing. A dam basin had grown stagnant and putrid, creating a virtual open sewer. Olmsted, fresh from his success with Manhattan's majestic Central Park, recommended flushing out the dam basin into a newly created park in the surrounding marshlands of the Fenway. The park masterfully wedded the demands of development to the desire for green space -- it not only solved the issue of dirty water in the Back Bay, but created a beautiful, unique public park in the process.

Boston leaders were intrigued with the idea of creating a linked series of parks, and Olmsted helped them realize this vision. The Emerald Necklace was a piecemeal project, created out of sequence, but with a central aim of interconnectedness. After the Back Bay Fens, Olmsted designed the Arnold Arboretum and Franklin Park, and later added links to the existing Commonwealth Avenue Mall through the man-made Muddy River and a park surrounding Jamaica Pond. Though Olmsted occasionally butted heads with city leaders over his design, the project moved expeditiously: the Necklace was complete by the end of the 19th century, a timetable of roughly 20 years.

The Emerald Necklace makes Boston's one of the most distinguished park systems in the country, not to mention one of the most durable. In Olmsted's time, much of the area surrounding the Necklace was rural, even wild, but today, these parks lie in some of the city's most populous neighborhoods. Franklin Park, for example, borders Forest Hills, Mattapan, Dorchester, and Roxbury; on a sunny afternoon, it buzzes with golfers, joggers, walkers, and families visiting the zoo. The park is large enough (527 acres) to succeed as both a passive wilderness and a playground, and its public appeal is undeniable.

Still, the city's investment in its green spaces has been inconsistent. At various points over the past century, the Olmsted legacy has been jeopardized by poor maintenance and outright neglect. The suburbanization of the post-World War II era, and the accompanying explosion of highway culture, eroded the city's concern for its urban spaces; though the late 1960s and '70s witnessed a rekindling of national interest in Olmsted and his parks, in most instances this interest was not matched by money. The passage of Proposition 2¹/₂ in 1978, which put a limit on property taxes, clipped the city's parks budget in half, and Boston's public green spaces fell into even deeper disrepair.

The problem is that public parks, unlike buildings, are perpetual works in progress. The finest of green spaces can quickly be destroyed by poor maintenance or lack of funding; parks must be constantly nurtured and improved.

Fortunately, some prescient city leaders have recognized this need. In the early 1980s, Mayor Ray Flynn launched a capital campaign called "Rebuilding Boston" that aimed to restore 80 percent of the city's parks and playgrounds within five years. By the end of the decade, Flynn's challenge had largely been met, and the Parks and Recreation Department budget had swelled from less than $7 million in 1983 to $13 million in 1989.

But most of this money was earmarked for maintenance, not acquisition. And in some ways, that remains the most pressing need. After all, it's one thing to construct utopian plans for future greenways and urban parks -- it's another thing to clean them and trim them and restore them. To design and construct a park system without a comprehensive plan to ensure its upkeep is inexcusable. Says Justine Liff: "If you can't maintain it, you shouldn't build it."

Now comes the hard part: sorting out who funds, builds, and maintains Boston's next generation of green spaces.

The Central Artery/Tunnel surface-restoration proposal is undeniably the marquee project on the horizon. It's hard to imagine a more prized piece of real estate than this downtown corridor, and if it's developed properly, it will have a significant impact on city life.

"A lot of the city has been sliced in two by highways," says Aldo Ghirin, a senior planner in the planning and policy division at Boston Parks and Recreation Department. "We now can put it together."

Critical planning is already under way. A working group of city officials, business leaders, and neighborhood representatives known as Boston 2000 has met to discuss the Central Artery/Tunnel corridor and establish basic guidelines for its development; three-quarters of the land has been earmarked for open space. But with a multiplicity of heavyweight players involved, including City Hall, the Massachusetts Turnpike Authority, the Massachusetts Highway Department, and the MBTA, there is concern about who's going to grab the reins. In a January report, the working group recommended the creation of an outside "entity" -- in essence, a new bureaucracy -- to lead the project.

"There have been a lot of power struggles going on in this corridor. Everyone wants to be involved," says Jill Ochs Zick, the Parks and Recreation Department's project manager for the Central Artery/Tunnel development, who is part of the Boston 2000 working group. Adds Boston 2000 cochair Robert O'Brien: "We want to create an organization for which this [project] is the highest item on the agenda."

Whatever agency ends up in charge will inevitably face difficult choices. There will be battles over what kind of new development is appropriate for the corridor (to date, only one structure appears certain -- a botanical garden for the Massachusetts Horticultural Society -- but there has also been talk of housing and business development). There will be debates over active versus passive recreation; while some may want to construct a tranquil urban oasis for tourists, there is also a legitimate need for playing fields in neighborhoods like Chinatown and the North End.

"I think the big questions are going to be how we strike a balance between the open-space needs and the development ones," says Zick. "And how will you balance the needs of the neighborhoods versus those of the tourism industry?"

Similar debates and power struggles are likely to occur elsewhere in the city. The Central Artery/Tunnel project is only one of a number of green-space initiatives currently in the planning stage. Other plans on the horizon include improvements in East Boston -- which, like the downtown corridor, has been divided by highway structures -- and the revitalization of the Charles River Lower Basin around Charlestown, which will dramatically improve an overbuilt, uninspiring shoreline. One of the Parks and Recreation Department's biggest future projects is the proposed $50 million dredging of the Muddy River.

Still more questions surround the open space along Boston's downtown waterfront, which is coveted by private developers (see "On the Waterfront," News, February 20). "We have done a very poor job in the past of planning the city waterfront," Mayor Menino says. "This is a chance to play catch-up." So far, however, the city's provisions for public green space in the seaport area have consisted of little more than narrow harbor walks and postage-stamp-size parks amid blocks of large-scale development.

The city also faces development-versus-preservation fights in the Jamaica Pond area, where neighbors want to stop a proposed luxury housing project to preserve open space. And there has been lengthy debate over modest plans to add green space to the lifeless brickwork of City Hall Plaza.

Tensions such as these are only to be expected when the stakes are so high. Such a convergence of green-space proposals hasn't occurred in Boston since Olmsted's time. People involved in the process are determined not to waste this rare chance.

"You dream about these kind of opportunities to really shape the city's future," Menino says.

Finally, there is the issue of money. Green space doesn't come cheap. The Central Artery corridor project alone will cost $118 million to $148 million, with $20 to $40 million targeted specifically for open space. The Charles River Lower Basin project has an $80 million price tag; the East Boston project is estimated at $20 million. And none of those figures includes maintenance costs, which run about 10 percent of the capital cost annually.

Some funding is expected to come from state and federal coffers, but the dependability of these sources is not assured. The federal Land and Water Conservation Fund, long the backbone of national open-space funding, is less reliable in the Republican-controlled Congress. As a result, the city is increasingly turning toward partnerships -- particularly with private business and neighborhood groups -- to fund open-space acquisition and maintenance costs. A successful example is Post Office Square, a charming downtown park that sits atop an underground parking garage; its upkeep is paid for entirely by local businesses.

"These type of partnerships have created some great success stories in the city," says Eric Antebi, a conservation specialist with the Appalachian Mountain Club in Boston. "We can have all these great ideas and plans, but unless there is money to back them up, then these are dreams that are going to be unmet."

For Bostonians raised on memories of elevated highways and chain-link fences, it may be difficult to envision the possibilities of this green revolution. Many residents are still unaware of or unimpressed by the open-space plans. While skyscrapers and superstructures generate civic excitement -- consider the headline-a-week hyperactivity over the South Boston waterfront development, or new stadium proposals for the Red Sox and Patriots -- urban open space doesn't always pack the same punch.

But great cities are judged as much by what lies between buildings as they are by the buildings themselves. And tomorrow's Boston should be known not only for what it builds, but also for what it doesn't.

Jason Gay can be reached at jgay[a]phx.com.