Geography

Singapore took a major step towards being self-sufficient in its water supply on 18 Sept 2013 with the opening of the Tuaspring Desalination Plant. It is Asia's largest seawater reverse-osmosis desalination plant and the second for Singapore.
The new plant adds 70 million gallons of desalinated water daily to Singapore's water supply, tripling the supply from the country's fourth "national tap". The other three "taps" are local water catchments, imported water and NEWater.

http://www.channelnewsasia.com/news/singapore/tuaspring-opens-latest/817978.html

1. How does the desalination plant convert seawater to potable water?
2. What are the four national taps of Singapore?
3. Why is water supply important to Singapore?