Introduction: Tokyo (01:58)

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In 2015, the Kinugawa River floods Joso city, leaving 65,000 citizens stranded. Tokyo boasts the most advanced flood prevention system in the world; when built, sea level rise was not anticipated.

Joso City (03:28)

Japan is typically struck by 20 typhoons during the annual storm season. Resident Hiromi Shinozaki describes struggling for survival; flood waters swept away her neighborhood.

Natural Disaster Prone Area (04:19)

Japan's economy depends on Tokyo. Environmental assessments reveal it is the most dangerous city in the world. See 1954 footage of record precipitation flooding Nagasaki; storm rainfall has since increased by 30%. In 2018, Typhoon Maria displaces millions, kills hundreds and causes billions in damages.

Typhoons (02:57)

Prof. Tomoya Shibayama compares traditional and modern storm systems; increasing sea surface temperatures intensify energy during landfall. In 1959, Typhoon Vera causes 5,000 deaths and $2 billion in damages; the surge prompts civil engineering projects, but defense capacities are limited.

Earthquakes and Tsunamis (02:34)

Japan is located on the Ring of Fire, and prone to tsunami producing earthquakes. In 2011, the Fukushima Nuclear Power Plant is severely impacted, setting off the worst disaster of its kind since Chernobyl. Urayasu resident Yoshitaka Udagawa describes tremors and ground liquefaction.

Liquefaction (03:04)

Earthquakes stimulate liquefaction; Dr. Christopher Gomez explains the process. Tokyo is built on sandy sediment, so when agitated, groundwater comes up, and buildings sink down.

Sinking Foundations (03:51)

Ground water pumping creates cavities under Tokyo and entire neighborhoods are sinking. Approximately 30% of the population lives below sea level; rising oceans are expected to put the areas underwater. Nobuyuki Tsuchiya and Gomez describe increasing threats complicated by decreasing budgets.

Kamaishi Disaster (05:09)

Kamaishi boasts the world's largest sea wall; it costs $1.6 billion and takes three decades to complete. The 2011 tsunami tore through it, flooding the coastal city. The defense is being rebuilt and engineers study causes for its poor performance;

Fighting Water (03:09)

Architects Vishaan Chakrabarti and Kristina Hill discuss water redirection and defense engineering failures. The Kamaishi seawall is being rebuilt to block and absorb storm energy. Tokyo contends with typhoons, tsunamis, earthquakes, rising seas, liquefaction, and sinking neighborhoods; Gom cataclysmic damage will happen if all threats simultaneously occur.

Discharge Channel (06:23)

In 1993, Tokyo begins constructing an underground flood management mega project. After record rainfall in 2015, it is filled to capacity, requiring a week of constant pumping operations. Experts discuss operational limits and concerns for surrounding neighborhoods.

Installed Safeguards (04:33)

Storm Surge Management Center's Hiroaki Takahashi explains how Tokyo's 44 floodgates function. Hall and chief engineer Nobuyuki Tsuchiya discuss the design and effectiveness of super levies. The ambitious plans require resident displacement during construction.

Building on Water (02:54)

Tokyo has the best coastal defenses in the world, but must continue adapting to rising seas. Architect Kunle Adeyemi designs infrastructure for water culture; see models of his floating school house. He discusses technology and materials used for globally implemented projects.

Floating City (02:31)

Engineer Toshio Nakajima proposes constructing floating foundations under low areas of the city; his design is based on the Mega airplane runway in Tokyo Bay. He explains logistics and energy generation for the project; see a computer simulation of the plan.

Changing Climate and Perspective (07:01)

Gomez explains the practicality of retreating from flood prone areas; he suggests remodeling during periods of temporary evacuation. Tokyo was an agricultural town built on low, flat land. Yoshitaka Udagawa and civil engineers express concern over reoccurring events, and adapting infrastructure to resist storms strengthened by rising sea levels.

Credits: Tokyo (00:30)

Credits: Tokyo