The death of a 22-month-old toddler who drowned in an unsafe backyard pool three weeks after entering foster care was entirely preventable, a coroner has found.

The case of Braxton Slager has again highlighted systemic failings in New South Wales out-of-home care, more than a decade on from the damning findings of the Wood special inquiry.

The deputy state coroner, Harriet Grahame, said the case again showed the urgent need for better resourcing of the system, including addressing the significant shortage of carers.

“The failings strike at the heart of the way we care for the most vulnerable children in this community,” Grahame said.

“In my view, many of the issues identified, while specific to Braxton’s death, also illustrate systemic problems. The ongoing scarcity of foster carers in the community is a serious issue that needs greater consideration than I can offer within the limited scope of this inquest.”

Slager was found floating in a pool in the western Sydney suburb of Stanhope Gardens in September 2014, three weeks after being placed in foster care. The home was unsuitable and posed an unsafe environment for Slager’s care.

The pool itself failed to meet basic safety standards, but the not-for-profit who fostered out Slager, Life Without Barriers, conducted no physical inspection before placing him there.

When police searched the home, they found “excessive amounts of alcohol” and prescription medication within easy reach of children. Tests on Slager found cyproheptadine – a strong antihistamine unsuitable for children under the age of two – in his blood.

The foster mother did not have the capacity to care for Slager, and was not properly supported by Life Without Barriers or her partner. The care was only meant to be temporary, although the foster parents were misled on the length of time Slager would be with them.

The boy’s father, Johnny Slager, was addressing substance abuse issues while fighting to get Slager back. He had been convinced by the NSW government to allow Slager to go into temporary care, despite having family available to take him.

Speaking outside court, Johnny Slager said the “whole system stinks”, Australian Associated Press reported.

“Something needs to be done about it for the little kids that are still in care now. My kid is gone and I spew about that. I really love him and I miss him so bad but he’s gone,” Slager said.

Grahame labelled the death a “terrible tragedy” and “extremely troubling”. She said it had caused Slager’s biological parents unbearable grief and had caused them to question their own survival.

“Tragically, a child who went into care to improve his chance of living in a safe environment, found himself in a situation of enormous risk,” Grahame said.