Pudong areas to act like sponge in pilot operation to store rainwater
The city’s major engineering designing body has begun renovating neighborhoods in Pudong’s Lingang area in a pilot operation to enable them to better capture and store rainwater “like a sponge.”
The trial projects have been carried out in 19 neighborhoods in Lingang New City along the East China Sea, and they will be promoted citywide, the Shanghai Municipal Engineering Design Institute (Group) Co said over the weekend.
The projects are part of the city government’s “sponge city” blueprint that is aimed at making local neighborhoods, streets and greenery lands better able to capture and store rainwater to ease the impact on the city during both rainy and arid seasons.
As part of the project in Lingang, which has been set as a pilot zone for the sponge city blueprint, grassed ditches, water-penetrating pavements, greenery rooftops and wetlands are being created to store rainwater. Scenic water pools will also be used to control rainwater and prevent flooding.
Solid pavements have been replaced by water-penetrating bricks that can allow water to penetrate at a fast rate to reduce water pooling on roads even during heavy rain, an official with the institute said.
Underneath each neighborhood’s “central garden” is a huge underground water pool, where the penetrated rainwater will be collected through pipelines. Some plants and grasses will be planted in the gardens over the rain collection pools to purify the rainwater.
The purified water from the pools will be connected with self-service car washing facilities installed on parking lots, the official said.
The city government has invested 800 million yuan (US$119 million) to turn a 79-square-kilometer region of Lingang New City into the nation’s largest “sponge city.”
Upon its completion in 2018, the region will be able to resist the severest of floods. The programs mainly cover parks and greenery lands, neighborhoods, streets and public plazas as well as waterways, according to the city government.
The city’s tunneling and civil engineering company STEC has developed several highly water absorbent materials for pavements and roads. A water penetrating asphalt, for instance, can allow water to penetrate it at a rate of 4,000 metric liters per minute.
Another type of material can store rainfall, which then evaporates under the sunshine, to reduce temperatures.
Nationwide, the central government aims to make 20 percent of Chinese cities have modern sewerage systems and infrastructure allowing efficient rainwater absorption by 2020, with that number rising to 80 percent by 2030.