Water is the source of UrbanLab's winning scheme. Dubbed “Growing Water,” it proposes a series of ecoboulevards to be developed throughout the city. These wide green swaths will treat all waste and stormwater naturally in Chicago and return it to the Great Lakes in a closed-loop system.

Each of UrbanLab's major ideas builds upon an existing engineered system within the city. The ecoboulevards extend a network of boulevards and parks that are more than a century old. Closing the loop of water undoes the reversal of flow from the Chicago River (its natural flow was turned back in the 19th century). Finally, a 109-mile-long system of 20th century stormwater drains known as the Deep Tunnel would no longer be necessary. UrbanLab would reprogram the drains as new mass-transportation routes.

The team viewed the entire Engineering an Empire series before starting work on their proposal. “There's a holistic and massive scale to everything they pro. le,” says partner Martin Felsen. “We wanted to work in that manner.” By creating a system of multifunctional natural elements within the city, UrbanLab's intervention simultaneously serves future social, recreational, and economic needs while conserving and sustaining the city's considerable reserves of fresh water.

Los Angeles

Infrastructure—collectively, the large-scale products of civil engineering that propel cars, trains, power, and water across the Los Angeles region—is the theme of L.A. winner Eric Owen Moss' riff on the city of the future.

Of the concretized Los Angeles River and the railroad tracks, huge tower grids, and freeways that effectively organize and subdivide today's Los Angeles, Moss says, “These are huge investments designed to solve very simple engineering problems.”

Moss proposes to bridge these defining elements and reconnect the city. Citing how Trajan's imperial baths were built over the remains of Nero's palace in Rome, Moss sees the future Los Angeles as a complex overlay of new structures and typologies, including a horticultural grid, water towers, what he calls a “NAFTA drape” (a zone for clean manufacturing uses that would help keep those industries in North America, rather than the Far East), new habitation structures spanning bridges and freeways, media towers, and a glass forest of housing.

Unsurprisingly, perhaps, Moss' Los Angeles is the most scenographic of the three winning entries, but Moss notes that his reconception of the city's infrastructure is a public policy proposal as much as a visual concept.

New York

A Manhattan transformed by rising seas, the product of melting polar ice caps, is the apocalyptic starting point of New York 2106 by ARO (Architecture Research Office). A hybrid between a literary fantasy and an Al Gore PowerPoint presentation, this is an elegy to New York's vibrant street life, which would need to be transferred to a new building type—“vanes”—as floodwaters claimed the lowest-lying streets of Manhattan.

“Rather than view [the flooding] as cataclysmic, we saw it as an agent of revitalization and regrowth for the city,” explains ARO principal Adam Yarinsky. The stacked horizontal vanes are suspended like piers over flooded streets and serve the multitude of functions that ARO predicts will remain part of New York life—they're residences, offices, shopping arcades, parks, and gardens. The existing buildings of the city are preserved by the intervention of the vanes. By reinforcing the historic order of the city, the street grid, topped by the grid of vanes, will remain the dominant influence on Manhattan's physical environment.

New York's perennial skyward thrust is augmented by twisting, Buck Rogers–inspired, open-lattice towers placed in the Hudson and East rivers. Providing evaporative cooling and water filtration, they become new vertical landmarks that celebrate the inherent sustainability of the 22nd century city.