I still have grass in my front yard (wasted space), lots of heat and sun, and would like to grow fig trees there, perhaps even a fig hedge. But I think there are water and drainage pipes going underground and connecting into the city lines somewhere under the sidewalk. A plumber around ten years ago fussed about roots growing into the plumbing from a hibiscus bush in front which has since died. The hibiscus was replaced by low chill cherry trees which stay small and so far have not caused a problem. Should I think about growing the fig trees there in sunken pots like the British are so fond of doing? Or spend a fortune on giant glazed pots?
How do other people have their fig trees thrive and still have plumbing that works? 

I'm not sure there is a lot to worry about.  Several years ago, I dug out a ~13 year old tree in Houston.  The thickest root was less than 1.5" in diameter and still pliable.  Most of the roots were in the top 12" of soil and only 4 or 5 grew down to anchor the tree.  I would think there is a single supply line and a single drain line to/from the house.  If they are more than 18" deep, There should be minimal interaction with fig roots.  If shallower than that, you could dig a trench around the pipes, line with weed cloth or an aluminum window screening, then fill with gravel.  Close the screen over the rocks and cover with dirt.  Check with a plumber to make sure it is acceptable.  

Altadena is an old town.  Are the pipes concrete or have they been replaced with something stronger?  I grew up in La Crescenta, not too far from Altadena.

Don't put the fig trees close to your house, especially if you are on a slab.  A fig tree's roots can lift and crack a slab.  Many kinds of trees can do this.  Figs aren't alone.  But getting that fixed is not cheap!  I suppose if your trees roots disturb the plumbing, the city could charge you for repairs.  When my late mother in law passed, we fixed up her home for sale.  The inspector deemed the slab unsafe, and we had to replace two rooms with new rebar and slab!  NOT cheap!

Suzi

Ficus' roots are known to be destructive ( not the figs only!). Are your pipes metal or concrete or something else?
If metal, you might be ok. In the dry season, the roots will search for water and travel far, lifting the driveways and foundations, as Suzi said.
If the pipes leak and are cracked , you might be safer not to plant in the ground directly

Suzi, Greenfig, I’m not sure what the pipes are made of. People were on a septic system for many years, but that was converted to a city hook up with Pasadena at some point in time. My new VdB is six to eight feet away from the house, but I’m told it stays small. The house isn’t on a slab. There’s a crawl space under the house, even a basement of sorts where opossums like to sleep. James, perhaps you’re right. I should check with a plumber first before I start digging. Otherwise, the front yard is perfect for fig trees. 

Mara, I think I'd just mark out where the lines run, and not plant right on top of them. Maybe 3 or 4 feet on either side. That way, should repairs be needed down the road, lines can be accessed without removing your trees.

1-800-dig safe, they will come mark the ground where the different lines are... at least that is how it works here.