Largest Underground Water tank in the World
The Metropolitan Area Outer Underground Discharge Channel (MAOUDC) is an underground water tank located in Kasukabe city, Saitama prefecture, Japan. It is the world's largest underground floodwater diversion facility, it is constructed during rain and typhoon seasons to diverse flood water to the major lakes and rivers near the city. It is located between Kasukabe in Saitama prefecture and Showa in Tokyo on the outskirts of the city of Tokyo in the Greater Tokyo Area, Japan.
Japan's government spent $2 billion (about 1 trillion yen) to build this underground flood diversion system and completed in the year 2006, which is a rare example of the disaster protection that international cities area unit activity as they face an era of utmost weather brought on by global climate change.
Kuniharu Abe, head of the underground system is responsible for controlling and operating the world’s largest tank.” In the Major areas of Tokyo, frequent and intense storms have triggered executives to think whether the structure’s protections area units are robust enough to hold the hydrostatic pressure. This becomes a priority to concentrate more because the Tokyo city prepares to host the 2020 Olympic Games.
Across Japan, rainfall raises up to 5.08 cm an hour and reached by 30% over the past 3 decades as estimated by Japan meteorological Agency. The frequency of rainfall of over 7.62 cm an hour has a sudden rise of 70%. The agency estimates that the increase of such intense rains to heating, leads this decade to consider as the world’s wettest.
Rising sea level is also a reason to build in the Japanese capital metropolitan region, which is home to 38 million people who are in the danger zone of frequent typhoons, while major renovation comes to open up the antecedent industrial city district to new residences and businesses. And years of pumping groundwater has diode some components of the city to sink by nearly fifteen feet over the past century.
In late 2015, significant typhoons and rain filled the tank in larger Edo, forcing a record 670 million square feet of water into the underground facility (MAOUDC). It took four days for the site’s four giant pumps powered by engines the same as those utilized in a Boeing 737 jet to clear the tank completely.
The construction work starts at Kasukabe in the early 1990s, at a time Japan invested lots of funds, and materials onto major public projects. But now, with a government debt more than twice the size of its economy and spending costs of caring aging population, the country cannot concentrate and utilize the resources to fund such meritorious projects.
This massive tunnel serves as a huge part during the time of the 2011 tsunami and saving more than 3000 lives. The Kasukabe city facilities this tank and serving to reduce most of the floods, thus resulting in the booming local industry, and then the region has successfully attracted by new shopping malls and several large e-commerce distribution centers. Officials at Japan’s Land Ministry says that, Still, the Kasukabe city remains a crucial part of Tokyo’s disaster protection systems, where the tank is located. Five vertical underground cisterns with nearly 250 feet deep which take in floodwater from four rivers of Tokyo.
A series of tunnels connect the underground cisterns to a huge tank, which is larger than a soccer field, with highs up by 60-foot strong pillars that give the tank feel like a temple. From the tank, large industrial pumps are used to discharge the stagnated water at a controlled pace to the Edo river, a larger river drain system that pushes the water into the Bay of Tokyo.