I caught a massive continuity issue they refer to Lake Emma as a reservoir in arches when Chase refers to it as an ancient natural lake and the Echo Reservoir is a unique location showcased in Jenna's Storyline in Echo when Heather attempts to flood the town
i had a whole long post previously, but i have changed my opinion since replaying jennas route. the river that feeds the lake was augmented by the dam when the town built it upstream, and a reservoir is essentially a dammed river—so it doesnt seem entirely false to use either term for lake emma. i read more about reservoirs than i ever thought i would, but i think no one would be terribly remiss in calling lake emma a reservoir, given that the hyperlinked hydrological website states that 'large artificial impoundments, frequently called reservoirs, are waterbodies typically created by placing a dam across a stream or river.' lake emma comprises whatever water is permitted to pass from the dam further downstream, so even if its not officially a reservoir itself, its damn (heh) close to one.
and if it was simply a mistake on the part of the author, i dont think its relevant enough to be a major concern to the events of the plot