It's not just in LA. They're network shows, so they're at the same time in most US markets.
And the second half of each conflicts with the first half of the Practice season finale.
Luckily, I have two ReplayTV's and don't watch Survivor (I watched the first one because it was on during the summer and there weren't any conflicts, but I haven't watched any of the new ones because there are too many conflicts during the regular season).