"In the last year or so the amount of work available has dropped off considerably because we are nearing the end of our own major wastewater treatment plant projects, and because other work from outside council has dried up as pressures on the economy have hit home," Mr Williams said.
"So we've made the decision to dismantle Hydrus as a business unit and bring its engineering functions back into the department structure of the council.
"Reluctantly, we've also determined that the appropriate staffing level at this stage needs to be eight positions, six less than the current number."
Mr Williams said three of the six affected staff members had already made decisions to voluntarily move on, leaving three other positions to be made redundant.
"We've offered to help those staff with other opportunities within council and externally."
Mr Williams said he was saddened to have to make the decisions as the people involved were competent and loyal staff members who had contributed substantially to the council's successful engineering projects over a number of years.
"I've been impressed by the professionalism of these staff members as we worked through this process with them over recent weeks, before reaching the conclusion that some jobs had to go.
"While naturally disappointed, they understand and accept the reasons that have led to these changes," said Mr Williams.
"Those who will be leaving us will do so with our thanks for their important contribution to our community and our ongoing offer of support for the immediate future."