Complex sentence: It, like many of the museum buildings, was taken apart and then transported to the museum where it was subsequently reassembled; in the case of the watermill, it was moved to stop it being lost forever as a result of the Alton Water Reservoir.
Split into simpler sentences: It, like many of the museum buildings, was taken apart and then transported to the museum where it was subsequently reassembled. In the case of the watermill, it was moved to prevent it being lost forever as a result of the Alton Water Reservoir.