Porterdale may have to refinance a one-year tax anticipation loan next year as falling property vaues have withered the city's budget and totally depleted its reserves. The loan taken out this fiscal year, which ends Dec. 31, was financed by BB&T for $150,000 and functions as a cushion to meet regularly recurring payroll and overhead expenditures while property tax and fee revenues arrive in lump sums at various times irregularly throughout the year. Last year, Porterdale borrowed $100,000 in a tax anticipation loan, which was repaid at the end of the year in full.