The head of the Los Angeles Department of Water and Power has announced he’ll resign at the end of the month.

General Manager Ron Nicols sent a resignation letter to Mayor Eric Garcetti and the City Council Thursday that explained his decision was his own and for, “personal reasons.”

Nichols, who has served as general manager for the last 3 years, listed a number of his accomplishments in the letter, and said he has not yet accepted another job in the utility industry.

“I was brought in to lead DWP by the prior administration and I felt it important to stay on afterward to provide time for the new administration’s transition,” Nichols wrote.

Just yesterday Nichols appeared at the City Controller’s Office to begin a formal audit of two secretive trust funds tied to the DWP employee union, the IBEW, that have together received more than $41-million in ratepayer money over the last 10 years.

Nichols has served as one of the trustees who controls the funds but has never publicly detailed how the money has been spent.

“I thank Ron for his service to our city as head of a department that serves every L.A. resident and business,” Mayor Garcetti said in a written statement. “I’m focused on continuing to reform the DWP to cut costs, improve customer service and increase transparency.”

City officials said Garcetti planned to look outside the agency for a replacement.

-- Eric Leonard (@leonardfiles)