Which of these two systems (conventional or sustainable) would you prefer? Why?
I think it is not a fair comparison.
And what covers "sustainable" actually?
The sustainable solution also have some problems related to e.g. need of more surface area, open acces to polluted waters for playing kids etc., but the "sustainable" picture however looks very green and nice and therefore I will prefer this.
Sustainable drainage system looks better.
sustainable is ofcause prefered but if the conventional is cheaper it might be easier to implement
Sustainable drainage systems
Sustainable drainage would be preferable, but considering the situation conventional drainage might be more effective.
Sustatinable drainage. It deals with the rainwater in a more clever way by making use of it instead of only seeing it as a problem.
Sustainable
The question is very biased: of course I prefer something where the word "sustainable" is and where you show pictures with grass and trees compared to the two below pictures...
The first one, i like the green view and it is also looks much better for both environment and humanbeing.