The Round Rock City Council unanimously voted Jan. 13 to move forward with a plan to lower wastewater rates and maintain current water rates for residential customers over the next three years. Wastewater volume rates, which are charged for usage above the base rate, will decrease by 8.8%. For residential customers using 10,000 gallons of water and 8,000 gallons of wastewater per month, the change will create $2.40 in savings per month.