Sluice Gates

CONTEXT

Water continuously redefines its own edge. Since the beginnings of maritime trade, designers and city planners have been tasked with developing methodologies to establish a more predictable definition of this edge to allow for continued economic vitality and to ensure public safety. Advances after the industrial revolution resulted in engineered solutions to water management often biased toward achieving hard-edged regulation of this boundary to allow for unmitigated access to ports, docks, and coastlines for trade. Twenty-first century cities are faced with an abundance of inherited infrastructures that are monuments to outmoded design approaches, and recent climate-related events have catalyzed the need to consider a new definition - pliant rather than prescriptive - for defining the limits of water in the city.

BACKGROUND

During the first half of the 20th century, Jože Plečnik delivered a sequence of forward-thinking infrastructural projects executed by in Slovenia - sectionally-unique approaches to designing the flow of the river Ljubljanica through the nation’s capital Ljubljana, which had in the past had a symbiotic relationship with the water but was prone to severe flooding. The relationship of any city to its water is implicitly fraught with a paradoxical complication, as it's necessary both to provide access to and separation from a volatile, shifting edge. Almost a century ago, Plečnik was working to identify design strategies - linkages, occupiable thresholds, engineered walls, and soft edges - that could incorporate or accommodate the inevitable cycles of flooding all while redefining space around the waters' edge to provide open access for the citizens of Ljubljana. 

Brimming with rich ornament and historical reference, Jože Plečnik’s architectural work during the first half of the twentieth century was seemingly out-of-sync with the social and cultural imperatives of his time; his interest in the vernacular imagery of native Slovenia (then Yugoslavia) and idiosyncratic building style were rich sources of reference for early postmodernists. Early surveys of his work largely overlook Plečnik’s large-scale but formally-minimal public works executed over the course of decades in parallel with his stylistically-exuberant architectural work. The two monographs of his work reinforce the legacy of an eclectic architect who operated in direct opposition to modernist ideals and feature his waterfront work as a footnote. Ironically, Plečnik’s inhabitable sections and multi-functional, programmatically varied infrastructural systems - not dissimilar in concept from modernist utopias like Le Corbusier’s Plan Obus for Algiers or Tange’s plan for Tokyo Bay - demonstrate a synchronicity with the forward-thinking visions of his contemporaries. 

Plečnik first began working on the waterfront in the 1920’s with a series of elaborate bridge projects, most notably the well-published Tromostovje (Triple Bridge Project), an ornamental crossing that linked the medieval historic city to an emerging modern business district. At the same time, the region dealt with a series of massive floods both in rural Pograd and in central Ljubljana, and Plečnik was tasked with taking on project of re-imagining the waterfront itself. His solution is defined by a modulated edge condition where a sequence of site-appropriate vertical sections delivers the water from rural Trnovo to central Ljubljana and back to the Slovenian countryside. Plečnik employed a variety of combinations of soft and hard edge conditions responding to requirements to contain storm swells or allow for natural absorption, all while retaining public access, where necessary, to the water. An example of one such approach is the implementation of terraced retaining walls at the east edge of the city. Here, Plečnik developed a hybrid system, retaining the wide bed of the river to accommodate storm surges but installing a series of wide steps that allowed residents access to the water for laundry. Experientially, the metered section demarcates like a hydrometer the seasonal rise and fall of water levels over the course of the year. 

APPROACH AND OBJECTIVE

Plečnik’s almost century-old waterfront sequence, with at least a dozen distinct segments, represents an overlooked contribution to the urban edge discussion.  The Ljubljana projects, an operative encyclopedia of a resilient infrastructural systems, are strewn out along a 2-mile stretch of the Ljubljanica and Gradaščica rivers.  Sponsored by the Architectural League of New York Deborah D. Norden Fund, I spent two weeks studying Plečnik’s design projects, sketching a series of sections along the river, following the banks of the Ljubljanica from the southern edge of the city, through the center of town and east to the Sluice Gate project, the monumental terminus. The product was a series of sketched drawings that allow one to understand the projects as a continuously developing section deployed at the urban scale. With notated drawings and photography, the dimensional, material, contextual specifics of each distinct segment of the edge become evident.  I also visited new projects in Ljubljana that both altered portions of Plečnik’s original project and created new waterfront civic spaces at the southern edge of the city.