The necessity of water is always present. As communities grow in population and economically, their demand for water increases. With a higher income, people want to consume more and all of their consumption needs requires water. There is only so much freshwater for everyone to use and landlocked countries can not desalinate salt water. Countries and states are fighting over water rights to different rivers which can lead to issues or even war.
On a smaller scale, Colorado, Nebraska, and Kansas have been fighting over rights to the Republican River. The Republican River is a major source of irrigation for these three Great Plains states. With higher heat and dry spells, more water is needed to irrigate crops. Colorado had to settle for $4 million with Nebraska for violating their water use rights. An ongoing lawsuit is continuing between Nebraska and Kansas because Kansas is not getting all of the water they were allocated. With climate conditions only expected to get worse, many farmers will fight with neighbors for over water use and waste.
International issues are rising as a result of drier conditions and water rights confusions. The tension in the middle east is rising between Turkey, Iraq, and Syria about the use of the Euphrates and the Tigris River. Both of these rivers start in Turkey and flow through each of the other states. As a result of all the political turmoil in Syria and Iraq, they were not able to regularly negotiate or find a solution towards water allocation with Turkey. Turkey without telling other countries created plans to build over 20 dams to increase their water supply. Debates over water rights continued but Turkey felt they deserved more water because their land is more fertile.
This continued debate for who gets how much water never came to an answer because of the internal conflicts in Iraq and Syria. The last negotiation table ended with Syria and Iraq about to sign an alliance to go to war with Turkey if any of the dams were built. With some of the internal conflicts ending, hopefully, an agreement can be made.
More international conflicts will rise as a result of water usage. Many countries either have no water or are wasteful.