Since becoming chief in 2009, Sponable has overseen the closure of three fire stations as well as firefighter layoffs triggered by budget cuts.
In a statement, Sponable said the layoffs have "strained relationships to the point where I believe it is in the District's best interest that I step down".
Sac Metro Fire Captain Christian Pebbles says the leadership change was a mutual decision by Sponable and the district's board of directors.
"They wanted to change direction with the management. They were not unhappy with any of his performance. But it gives them the opportunity to open up and modify salaries and benefits to upper management and with the new management it will be quite a bit of savings for the organization and the taxpayers."
Sponable's departure takes effect on April 1st. Deputy Chief Kurt Henke will take over on an interim basis after that.