An average utility bill in Waco, Texas, could increase by about $6.81 a month under the city's draft budget, according to the Waco Tribune-Herald. Here's what to know When the new budget year starts Oct. 1, utility costs are projected to rise on average. For single-family homeowners, however, lower property valuations and a tax rate that would stay the same would largely offset that, leaving the combined monthly total for property taxes and util…