From looking at the E3 docks map, I've noticed a similarities in to ickypop and I'm pondering if the proto-Ravenholm chapter would begin with a setpiece of an Ichthyosaur jumping over a dock and destroying it (in a callback to HL1). Plus the existence of quarry02 makes me think that the fight would have happened in a flooded quarry originally rather than a lake which ties in to the Quarrytown concept.
How much of a role would the Ichthyosaur have played in the 2001 Storyline? Would this have been a one-off event considering the drained oceans?