Water is the most important resource for the whole of humanity, we cannot live without it. This is just one of a list of many reasons why we are obligazed obligated to preserve its, despite the consuming consumption of water is rapidally increasing; it is not a good signal sign. What are the causes? There are many global causes such as population growth or climate change but undoubtedly, the very most important issue is the water's waste waste of water! Furthermore, there are many ways to waste it, apart from own uses, mainly thanks to farmly consumes consumption by farms, and especially wrong positions the poor positioning of crops around the world. 

According to the author's opinion, a "tradable-usage rights", could be a right (or correct) answer to this problem. For instance, it is a good situation when a farm can borrow water from who don't doesn't need its. That is a type of market in which it is possible to lend and borrow rights without paying for them!

I hope this helps you :)