Water crisis is a term that refers to the status of the world’s water resources relative to human demand. The term has been applied to the worldwide water situation by the United Nations and other world organizations. The major aspects of the water crisis are overall scarcity of usable water and water pollution.
1.6 billion people have gained access to a safe water source since 1990.  The proportion of people in developing countries with access to safe water is calculated to have improved from 30 percent in 1970 to 71 percent in 1990, 79 percent in 2000 and 84 percent in 2004, parallel with rising population. This trend is projected to continue. 
The Earth has a finite supply of fresh water, stored in aquifers, surface waters and the atmosphere. Sometimes oceans are mistaken for available water, but the amount of energy needed to convert saline water to potable water is prohibitive today, explaining why only a very small fraction of the world's water supply derives from desalination.
There are several principal manifestations of the water crisis.
Inadequate access to safe drinking water for about 1.1 billion people
Groundwater overdrafting leading to diminished agricultural yields
Overuse and pollution of water resources harming biodiversity
Regional conflicts over scarce water resources sometimes resulting in warfare
but still the water crises are on, the droughts are on their way so what do you think the next crises will on be the water or oil???