Maybe. The thing is though, water and its sound are integral to good garden design. The effect of both is the serenity one feels when they are present. So even if you think your garden is too small, think of putting in a small fountain for instance or another water feature. A wall fountain perhaps?
Here’s a small tour of a small garden of just 6m x 4m and its decent sized tear-drop shaped pond of about 3m x 1.5m for you to enjoy.