Early civilization mostly flourished along rivers because rivers provided a reliable source of water, irrigation and transportation. Hence, people could be assured of drinking water. Agriculture could flourish due to the availability of irrigation. People could travel in boats on the river which was important when roads were not well developed.
In present time, these factors are not very important. Water for drinking and irrigation can be transported. Rivers are no longer the main form of transportation. Hence, civilization can flourish even in places that are far from rivers.