Green Infrastructure and sewer capacity challenges
Everyone is at it… looking for alternative ways to address chronic and often hitherto intractable problems with sewer capacity, overflows and pollution, and surcharging/flooding affecting property and presenting serious human health risks. And at the same time (for the same money) create attractive landscape features.
The Thames Tunnel projects in London have been investigating raingardens as retrofit options and there has been a publicly stated intention for the Washington DC sewer tunnel project ($billions) to also retrofit some raingardens and similar features.
One of the areas considered for SUDS retrofits, Counters Creek, London (above).
In Guangzhou, China, city engineers and planners are looking at potential sites too for retrofit raingardens as an option in some of the gardens of properties along a tributary of the Pearl River where it flows through an attractive part of the city. Storm sewage discharges from the local combined sewer are currently managed by holding tanks with discharges to the river. The situation is recognised as an interim action, bringing some improvement, but further measures are needed and retrofit raingardens are to be considered in a new project, hopefully starting in 2017.
Brian J D’Arcy, C&D Associates