The number of children entering the care system in Denbighshire has increased by 58% in recent years according to an internal report.
It states the increase took place between 2008-2009 and 2009-2010 with Rhyl being highlighted as an area of "high activity".
Councillors will discuss the findings which says while the overall service performs "well," there are concerns over budget pressures.
There are fears of possible overspend.
Across Wales, the report by the Denbighshire council's Director of Social Services and Housing says, referrals to social services are at their highest since 2000.
It says the Association of Directors of Social Services Cymru (ADSS) gives reasons for the increase in looked-after children, which include "an increased awareness of child protection in professionals and the public".
It also highlights pressures on families from the recession, and "unfunded judicial judgements requiring more children being classed as looked after and entitled to enhanced services".
The ADSS and the Welsh Assembly Government have jointly commissioned further research into the changes.
Denbighshire's document, to be discussed by the Social Services and Housing Scrutiny Committee, was compiled to provide an overview of the service and financial performance of children's social services.
It says "work volume, the demands of information systems, recording expectations and recruitment issues are creating particular pressures at the front door".
It says the situation is similar across the UK, adding: "This workload pressure is now affecting all the teams as we have had a rise in the number of children coming into care and on to the child protection register."
The report also highlights one seaside town, saying: "The activity in the Rhyl area is particularly high, with high mobility, social need and poverty."
It also says there is "evidence from other north Wales authorities as well as from English authorities, that the nature and severity of the needs of children being referred for services has increased over the last 18 months.
"There are also more court proceedings being initiated in response to the more serious levels of need and harm which are being identified".
The report states that a workload management system is being developed in Denbighshire, and that "the service continues to perform well in most areas, good outcomes are being achieved for children and young people and their families".
It also says: "The increase in the number of children in care and the more severe needs of many of the children who have been identified recently, is now resulting in budget pressures within this year as placement costs have risen. We are closely monitoring this."
It is thought the department, which has a gross budget of £9,26m, could overspend by £140,000.