The phones started ringing and e-mail traffic picked up Tuesday afternoon, just about the time reassessment notices first appeared in homeowner’s mailboxes. As predicted, most homeowner assessments decreased overall, but it was how they declined that shocked taxpayers and the Board of Supervisors alike. Land values went way up, and house values went way down. For one Mason District homeowner, whose overall assessment decreased, the land value was $325,000, an increase of $145,000; the house was valued at $62,960, a decrease of more than $200,000! Another Mason District homeowner in Falls Church saw her land value more than double, while the house value dropped to $54,210.