Final answer:
The Tigris River is not equally shared among the surrounding countries due to the presence of dams built by Turkey.
Step-by-step explanation:
No, the Tigris River is not equally shared among the surrounding countries. Turkey, Syria, and Iraq are the main countries that share the Tigris River. However, Turkey has built dams along the river which restricts its flow downstream, affecting the water supply for Syria and Iraq. This has resulted in ongoing conflicts over water resources in the region.