Alexandrina Council will begin looking for a new chief executive officer, after Glenn Rappensberg announced he would not be continuing his tenure at the end of his term.
Mr Rappensberg told his staff on Monday that he would not seek a second contract once his five-year term is complete in May next year.
He cited family reasons as to why he could not commit to another term.
"While my decision may surprise some people, I simply didn't feel that I could make the commitment to another five-year term, which is a significant contract in local government, particularly given the current failing health of my elderly parents who are in Queensland and have become increasingly dependent on my support," he said.
"I have just returned from Mount Isa (on Monday) and unfortunately, it is very clear that I will need more flexibility to be able to support Mum and Dad going forward."
He said he was proud of the work he had undertaken with the council team which improved the region.
Some of his personal achievements included being involved with developing the council's 20-year regional Vision to Thrive - A2040 plan and the comprehensive Economic Development Strategy, and increasing community engagement through the Village Conversations and Village Innovation Plans.
"We also have more than $50 million in projects underway, including the revitalisation projects for Goolwa Wharf Precinct and the Strathalbyn Town Centre, along with the Goolwa Beach Master Plan, creation of the Signal Point Experience Centre, and key upgrades for Goolwa High School, Strathalbyn Aged Care and numerous SA Ambulance Stations," he said.
"I will leave the role with great memories and real pride in the contribution that I have made and the achievements of our entire Alexandrina Council team.
"Our region has a great future and I look forward to watching its continued growth and success with a new CEO at the helm."
Mayor Keith Parkes said his partnership with Mr Rappensberg had benefited the district's communities.
"Together as CEO and Mayor, we have advocated strongly for the Alexandrina community and Mr Rappensberg's contribution and influence has driven positive and sustainable outcomes for Alexandrina that will be celebrated for some time," he said.