I'd see if you can't double that amount of water. And perhaps even some walking on "off" days?
If you're accurate in tracking your cals, then your body has to be burning more cals than you're taking in.
I really admire those stalwart individuals who can weigh in only once a month or less--they likely don't stress over plateaus as much as we do.
Personally, I've had a week or two period where I stayed the same or lost, perhaps a pound. Conversely, out of the blue I've had back-to-back 7 lb. loss weeks. I can't explain it so I try not to worry about it.
I've sure others more knowledgable than myself will add some suggestion.
47 M 5'8"
May 4, 2010...... 440? lbs. (Start FitDay Size 60 Jeans)
June 19, 2010.... 393 lbs. (First Weigh-in)
June 19, 2011.... 229 lbs. (164 lbs. gone in one year :-)
Current Weight... 185 lbs. (Size 36 Jeans)
Next Goal 169 lbs. (07/04/12)
Ultimate Goal 165 lbs. (12/31/12)
The best exercises for weight loss are Fork Putdowns and Table Pushaways.