Chuck, here is the best description I could find:
"Return toward the start position in Auldale and proceed east and then north toward the park. Pagans populate the park and unless you've been earning favor with the cornerstones, they won't appreciate your intrusion. Put out torches, sneak in corners, use long-range broadhead arrows, or toss a couple flashbombs to distract the Pagans while you snatch the amulet. It's located on a table to the left of the fountain. Note that this fountain will also replenish your health--though just a single time usage.
Return to the pump station and approach the vines covering the entrance. The amulet makes the vines disappear. Enter the pump station and use the valve to drain the canal."
Do the vines disappear for you? Maybe you still need to use lockpicks.
There is a picture of the table in the guide. It has decorative squares. If this doesn't help, ask at TTLG.com. They can probably answer your question.
http://www.gamespot.com/features/6100413/p-22.html