The short and simple answer is yes! But let us convince you why. Firstly the body is composed of about 70% water. It is essential for life. Humans can survive around 30-40 days without food, and many have survived longer. But without water it's only about 3 days.
It is very much dependant on lifestyle, body size and caffeine intake. Women need on average about 2.2 litres of water a day and men about 3 litres. This is pure water, not juices, soft drinks, tea or coffee. If you do any strenuous exercise then you will need to consume more.
Water in coffee and tea does not count as the caffeine in these drinks act as a diuretic and will increase water loss. You would be best to drink an extra glass of water (on top of the daily recommended amount) for every caffeinated drink you consume.