Going with the Flow: Making Urban Tidal Cycles Visible through Design

As the world urbanizes, an increasingly large portion of the human population finds itself within 100 kilometers of the ocean–40% and growing (1)–in cities more often than not built around bodies of water that are deeply connected with the ocean’s tides. Despite this fact, fewer and fewer urban residents–even those who might take ferries or cross bridges every day–are actually aware of the tide level at any given time, just as most urbanites probably do not know the current phase of the moon . Moreover, many are probably oblivious to the importance of the tidal cycle to the biological rhythms of tidal wetlands and river ecosystems. The ocean’s rise and fall determines the behavior of shorebirds and marine mammals, and some animals are specifically synchronized to particular tidal events–the “circalunar clock.” The California Grunion, for instance, time their egglaying to lunar cycles, ensuring that freshly laid eggs on beaches will be swept back into the ocean by spring “supertides” (2).

Guilford Marsh: Note the High Tide line

This afternoon I had the opportunity to kayak through a beautiful coastal estuary in Connecticut, and I was struck by the way in which the moving tide left strong evidence of its movement on the landscape. The glittering salt lines on the reeds not only showed the high tide level but also suggested how recently this level had been reached. It was impossible to be near the water and not empathize with the daily push and pull of the marsh; as the tide went out and siphon holes were revealed, plovers descended onto the mud to hunt mussels. How can a building embody that kind of information?

Flood marker for a 1530 flood

In Hotaling Place in San Francisco, the waves in the paving follow the city’s original pre-landfill shoreline

We are all familiar with the flood level markers on major buildings in flood-prone communities–some, such as the ones in Rome, can get elaborate–but how can daily tides be visualized in a compelling and dynamic way?

 

Curl la Tourelle Head Architecture, Thames Tidal Powered School, Section with turbines in basement

This push and pull is not just a Romantic notion tied to distanced admiration for nature; architects in London are quite seriously proposing waterside buildings that can generate almost all their energy from integrated turbines that harness the tidal flows of the Thames River (3).

 

 

the Arcata Marsh, an engineered wetland that treats wastewater

 

Tides can also affect urban climate and, in the case of engineered water treatment wetlands like the one in Arcata, CA, they are essential in the final stage of washing out freshwater-salty threshold ecosystems. Even in a highly urbanized tidal location like New York City, the daily flows of water help to flush out estuaries and sustain urban wildlife.

One rather blatant example is found in proposal by BIG for a “reverse aquarium” as part of its “Big U” project for Manhattan’s waterfront. The “aquarium” enables visitors to see the current tide level and compare it to highs, lows, and historic events. It also becomes a useful tool for tracking sea level rise.While the proposed design details draw from an admittedly uninspiring minimalist vocabulary, the idea that these kinds of viewing windows could become more commonplace in tidal cities–perhaps as features of waterfront parks or visitor centers–is quite intriguing.

In classic BIG style, an extravagant rendering of a proposed “reverse aquarium”

 

What is missing from BIG’s proposal, however, is a more nuanced architectural vocabulary with an empathetic relationship to the flows and dynamism of the tides.

This is the challenge taken on by Kennedy Violich Architects (KVA) in their project for a ferry terminal at East 34th Street. The lightweight, triangular steel structure of the pier holds up a translucent, reflective canopy that, in the words of the designers, “reflect[s] the changing, natural effects of light and water.” Most commendable is the way in which a wide range of materials–metal shimmering walls, curving glass partitions, custom wood seating–is brought together into a shared language of waveforms. Moreover, the presence of these “flowing” elements precisely at a point where New Yorkers change modes from bikes, walking, and ground transportation to water taxis helps to solidify the analogy between human and tidal flows–an apt one, especially in a city like New York where the morning rush downtown and evening flow out to the suburbs are in themselves a cycle as predictable and essential to the city’s human ecology as the tides are to its natural ecology.

KVA’s Ferry Terminal at Night

Waiting Area, showing flowing glass, metal, and wood elements

Most intriguing is the way in which the project integrates monitoring technologies and real-time data into its visual display:

An interactive river environment monitoring system, created specifically for this project, tracks the East River water speed and the direction of daily tidal flows which are important to the health of NYC’s water supply. This ambient river monitor is integrated into the three large lightwells of the Ferry Terminal roof canopy. Sensors along the boardwalk capture real-time pedestrian flows between water and land. Subtle changes in the color and direction of LED lighting in the roof canopy lightwells reflect the flows of people and water, creating a civic urban infrastructure that links natural and constructed urban ecologies. (4)

KVA’s monitoring and lighting system for the Ferry Terminal

While the actual system for connecting passenger and tidal flows to lighting displays may seem a bit esoteric–and is probably not immediately apparent–just as the solar-activated flow variation in the water fountain system in Van der Ryn’s Real Goods Store (see previous post) takes some observation to fully understand, so too does KVA’s system take some attentive studying to comprehend. That does not take away, however, from its more immediately obvious dynamic nature. In creating a subtle system, KVA allows room for subconscious empathic experiences–as passengers wait in the terminal, changes in the color of light that correspond with high flows of water and passengers may be registered only subliminally–and yet, if they cause an increase in attention to the environment, half the battle is won!

We leave off on a particularly interesting “translation” of tides into sensory information: a tidal-powered organ designed by architect Nikola Bašić for the coastal Croatian town of Zadar (5):

 

1. http://sedac.ciesin.columbia.edu/es/papers/Coastal_Zone_Pop_Method.pdf
2. http://nautil.us/issue/46/balance/the-evolutionary-pull-of-ocean-tides
3. https://www.dezeen.com/2017/06/14/thames-tidal-powered-school-vision-london-curl-la-tourelle-head-architecture/#disqus_thread
4. http://www.archdaily.com/873704/east-34th-st-ferry-terminal-kennedy-and-violich-architecture
5. https://www.treehugger.com/culture/wave-powered-sea-organ-nikola-basic-zadar-croatia.html