Don't worry so much about how much you get paid for doing different streams. You'll get paid what you're worth based on your smarts and experience (and negotiating skills - yay free accommodation and flights!). If you suck at what you do, you will eventually get paid less than someone who is good at it.
More importantly, you'll hate it if you do civil and work in construction for the extra $5K p.a. and spend the rest of your life wishing you were in a nice office designing cars or power systems or prosthetic limbs. I'm doing civil btw, because I'd rather design dams and skyscrapers than welding rigs and air conditioners.
For those of you who still want to know salaries, here are the APESMA figures for median graduate total packages (not base salaries, which are 5-10K less) from june 07:
by discipline:
Chemical: $54148
Civil/structural: $59440
Electrical: $60447
Electronic/comm: $53822
Enviro: $51580
Mech: $54001
Other: $57112
by employer's industry:
consulting/tech services: $56680
construction/contracting/maintenance: $59825
mining etc: $60312
oil/gas exploration/production: $55353
electricity/gas supply: $58720
water, sewerage, drainage: $50070
communication inc telstra: $55045
other non-manufacturing: $47632
Ooooh look, construction and mining pay heaps! Lets all do that! I hope you enjoy being on hot dusty construction sites in the middle of nowhere working 60 hour weeks surrounded by bogan labourers (personal experience speaking loudly here... I'm going to go into consulting or research and sit in a nice office in Sydney, thank you very much)
For those of you who would like to know about employment oportunities, here is some info. Again, this is completely irrelevant in making career choices, because YOU WILL GET A JOB AS LONG AS YOU DON'T SUCK AT WHAT YOU DO. These are combined figures of 05/06 graduates seeking professional engineering jobs in march/april 07 (ie after about 6/18 months):
Chemical: 14.3%
Civil/structural: 3.8%
Computer systems/IT: 18%
Electrical: 6.4%
Electronic/comm: 10.3%
Enviro: 6.5%
Mech: 10%
Other: 12.3%
Note also that only people who want people to know their salary respond to these surveys, and that sample size is only 116.