Jake's Wounded Nose (Symbol)
The cut Jake receives on his nostril when investigating the Oak Pass Reservoir is a symbol of the personal risk involved in his profession. As a private investigator, Jake's job is to spy on people suspected of dishonest behavior, such as spouses who might be cheating. With Evelyn Mulwray's case, Jake becomes embroiled in a case of high-level corruption that involves murder and conspiracy. When thugs catch Jake trespassing to look into what Hollis Mulwray was checking at the Oak Pass Reservoir at night, they slice Jake's nose as a warning to stay out of other people's business. Jake's nose is a suitable location for the warning wound, as it evokes the idiom of sticking one's nose where it doesn't belong.
Albacore Club Quilt (Symbol)
The Albacore Club flag Jake sees while visiting the seniors' rest home is a symbol of Noah Cross's involvement in the land-buying scheme Jake discovers. Upon discovering that a recently deceased man's name was used in the purchase of farmland in a valley outside of Los Angeles, Jake visits the rest home where the man had been living. There, he sees that other seniors have been listed as the new owners of similar parcels of land in the valley. Knowing something is afoot, Jake speaks with a woman who doesn't know anything about the land she supposedly owns. He sees she is quilting with scraps of fabric, one of which shows the emblem for the Albacore Club, an establishment owned by Noah Cross. With this information, Jake pieces together that Noah Cross is behind the shady land purchases.
Water Dumped During a Drought (Symbol)
The water Hollis Mulwray learns is being dumped in secret is a symbol of high-level corruption and conspiracy. Set in Los Angeles at a time when the region is struggling through a drought, Chinatown depicts Jake learning that Hollis was killed because he discovered that Noah Cross is orchestrating a plot in which thousands of gallons of water are being released from reservoirs at night in order to create false scarcity and shore up public support for a new dam project. As Jake learns more, it turns out the dumped water is merely one component of Cross's greater scheme to buy up farmland and incorporate it into Los Angeles so he can become even wealthier.
Second Cigarette (Symbol)
The cigarette Evelyn lights when she already has one burning is a symbol of her trauma. The moment happens when she is in Jake's office arranging an official deal for him to take her on as a client. When Jake asks about her father, Noah Cross, Evelyn is visibly shaken by the subject. To calm herself and occupy her hands, she withdraws a cigarette from her case and lights it, having forgotten that she already has one burning in the ashtray. Jake immediately notices the shift in her composure, studying her as she lights the cigarette. From this gesture, Jake understands that Evelyn has a complicated and perhaps traumatic history with her father.
Chinatown (Symbol)
The "Chinatown" referred to in the film's iconic final line is a symbol of powerlessness. After Evelyn dies as a consequence of Jake trying to protect her, Jake tries to walk away from the scene but cannot help staring back at her corpse. Walsh tells him, "Forget it, Jake. It's Chinatown." In this line, Walsh is saying that there is nothing Jake can do at this point, just as there was no way for him to undo the harm he unwittingly caused the first time his actions brought about disastrous results while he was working for the DA in Chinatown. Like last time, Jake will not be able to actually forget what has happened as a result of his actions; all he can do is walk away and give up trying to fix his mess.
