Shanghai Daily news

The city will build four new drainage systems at Shanghai World Expo venues to ensure the grand event will not be swamped by any storms.

The systems will have three times the drainage capacity compared with downtown levels, and will be separate from sewage collection pipelines, the Shanghai Drainage Administration said yesterday.

It's part of the city's upgrading of all drainage systems, which have caused problems during downpours that flood the streets and force sewage pipelines to overflow into local waterways.

The goal is to double the overall drainage capacity by 2020 from this year's level.

The new systems, three in Pudong and one in Puxi, will be able to deal with rainwater of up to 108 millimeters each hour.

The drainage pipes will go with a storage system for rainwater, comprising huge tanks that could be placed underground. The administration has already budgeted for 120 million yuan (US$16 million) to upgrade 10 kilometers of sewage pipelines.

The city's overall drainage capacity has reached 2,370.5 cubic meters of water per second this year, an increase of 10 percent from 2005, covering more than 600 square kilometers.