The city departments below can all be reached by dialing 3-1-1 or by dialing direct or going to the listed websites:

Abandoned Vehicles (800) 222-6366
Animal Services  (888) 452-7381
Building & Safety Permits
Building/Zoning – report a violation
Bulky Item Pick up  (800) 773-2489
Damaged Stop Sign 
Department of Transportation (213) 972-8470
Emergency and Crisis Information 1-800-439-2909
Empower LA  (213) 978-1551
Grafitti (213) 978-0228
Homeless (213) 683-3333
Illegal Dumping (800) 773-2489
L.A. Fire Department  (213) 978-3800
L.A. Fire Department emergency 9-1-1
L.A. Police Department non emergency 800: (877) 275-5273  (1-877-ASK-LAPD)
L.A. Police Department emergency 9-1-1
Loud noise and parties: 877-275-5273
Pothole Repair 800-996-2489
Sanitation   (800)773-2489
Sewer problems (323) 342-1562
Sidewalk repairs 800-996-2489  
Street Light Repair 3-1-1
Street repairs: call Street Services 800-996-2489
Traffic Safety and Controls (213) 972-4990
Trash Pick Up (800) 773-2489
Tree Trimming 800-996-2489
West Valley Police Station 818-374-7611

Transportation

Metro Rail: Call (800) COMMUTE or Online
DASH/Commuter Express: LADOT
(213, 310, 323, 818) 808-2273
Regional Buses: Call (800) COMMUTE or Online
Trash Pick Up: Sanitation - This email address is being protected from spambots. You need JavaScript enabled to view it.
Tree trimming: call Street Services 800-996-2489

Note that www.lacity.org has a new website up and that email contact is available by clicking links.