The effects of global warming can be seen on a daily basis. For example there are the great floods that occurred in 2008 and 2009 in the UK. These point to the fact that the sewer systems are old and they cannot handle the new situations anymore.
Useful alternatives for the old systems are the sustainable drainage systems (SUDS). These do a lot more than just mitigating flooding, they also improve the quality of water, cooling and greening the city regions this way reducing the high temperatures in the urban area and improving the general health of the population.
In the majority of the cases the old sewage systems gather all the water from impervious streets and pavements in the storm sewage systems pass through pipes, gully pots and water treatment facilities.
The difference between these and SUDS is that the later offers treatment to the water right on site.
While in the first case water is considered to be an hazard, in the second case it is seen as an asset and valued as such.
The â€˜urban heat island effectâ€™ has been known since 1919 and it is caused mainly by the lack of vegetation in the urban areas. SUDS devices have been used to create green roofs that have the great advantage that they can be fitted to existing constructions and so they donâ€™t need any extra space.
According to a study, in case 50% of New Yorkâ€™s flat roofs would be greened, the effect would be reduced by 0.88C.
From the land takeâ€™s point of view it is true that the developers make a lot less money from having a detention pond than having an extra house. Nonetheless in case the house has SUDS, like ponds and wetlands, these could make up for the loss of land.
Just as any other kind of system, they would need some maintenance to make sure that they perform their duty accordingly. In case people donâ€™t manage to sort out the ownership, nobody will be responsible for the costs of maintenance.
Although all this seems to be great in theory, there are a lot of people claiming that there is no long term evidence that the SUDS systems are really working.
At the moment the production costs of the SUDS are quite high, but the same thing was true for PCs. Hopefully with the increase of the production the price will decline gradually.