I have urine test at a methadone clinic on Monday morning will i pass if you took some xanax the past couple of weeks if i drink water for a couple of days before the test?

Depends on how much you mean by, "some." According to the probation department in my county Xanax will show up for up to five days for occassional or short term use. Perhaps 10-14days for heavy or long term use. Also if you drink a normal 64ozs of water a day drinking extra will not really help unless you drink so much as to cause a dilute sample but then the test will show up dilute unless you take the proper steps to ensure it doesn't.