Foster care in Kirklees cost more than £11m last year.
And shock figures have revealed that much more is being spent on outside agency cover than on its own carers.
During 2017/18 Kirklees Council forked out £6.8m on foster carers through outside agencies.
Spending has rocketed by almost a million pounds in the five years since 2013.
In the same period the authority paid out £4.3m for its own in-house foster care.
The overall total was an eye-watering £11,180,582.
The spiralling cost of agency workers is due in part to the council’s inability to recruit carers.
In July the council’s Interim Head of Corporate Parenting, Steve Comb, said Kirklees was struggling to fill a hole in its foster care provision.
Describing the problem as “a real national challenge” he indicated that the council needed 500 inquiries a year - equating to 40 inquiries a month - in order to sign up 30 new fostering households.
Based on the most recent figures made available via a Freedom of Information request, the council employed 216 approved carers in 2017/18.
That number has reduced from 238 in 2013/14. The highest number of carers over the last five years was 241 during 2014/15.
During the last five years two carers left council employment to foster for an agency.
The council does not collate data relating to the number of individual foster carers employed in the district through outside agencies.
A spokesperson said: “Agency carers living in the district will be caring for children from multiple local authorities and although we are notified of children coming into the district this information is not always accurate in that, when children move on, the update from the placing local authority is not always received.”
Allowances paid to in-house foster carers rose from £3.8m in 2013/14 to £4.3m in 2017/18. The figures incorporate allowances and transport costs.
But over the same period the council paid more to foster carers through outside agencies. The figure jumped by almost a million pounds from £5.9m in 2013/14 to £6.8m in 2017/18.
During the period 2013 to 2018 the number of children aged 0-19 fostered in the district by in-house carers remained roughly the same: 326 in 2013/14 dropping to 317 in 2017/18.
Fewer children of the same age range were fostered through outside agencies during the same period: 160 in 2013/14 rising to 188 in 2017/18.
