OLIVE TWP., MI (WHTC) - Ottawa County Administrator Al Vanderberg told board members yesterday, during his annual “state of the county” message, that he expects the county’s tax base to increase by the end of the year, based on trends showing new single-family home construction up by 57 percent last year. Residential units comprise 70 percent of the county’s tax base. He’s drawing up a county budget with no revenue increase as a precaution.