Kitty -
Sometimes taivana Yellow Wagtails can show a facial pattern similar to Citrine Wagtail, as in your photograph. However, I agree with Forrest that the pale suround to the ear-coverts on Citrine Wagtail is usually more obvious than on the bird in your photograph. Also. Citrine Wagtail would show a pale centre to the ear-coverts, which the bird in your photo doesn't show, & the crown would also appear lighter.
So, although the bird does show a "C" around the creek, I think it is a taivana Yellow Wagtail and not Citrine.
Regards,
David
