You are on time and that is a great reflection photo! I've often thought someone should host a challenge specifically for photos with reflections and silhouettes. There have been times when I have chosen both as contest winners, even though technically they were not shadows.

Shadow is the absence of a light. Stand with a light behind you and you will cast a shadow - object (you) blocking rays of illumination (light).

Reflection -reflection comes from the bouncing of light off one source and on to another.
(Look in a mirror, you are reflected in it.)

If the sun was behind the tower it would cast a shadow on the water by blocking the light.