Why is a river a gift to a desert land

Lyndon B. Johnson's July 1964 speech dealt with Civil Rights, saying that we all believe that all men were created equal, but many are not treated equally. That civil rights law Johnson was going to sign had been filed by John F. Kennedy a year ago. The objective of the law was very simple, not to restrict the freedom of any American while he respects the rights of others, the only limit to be happy is his own ability and does not grant special treatment to any citizen.