Local authorities are under intense pressure. Rising demand for services, constrained budgets, and structural change (including reorganisation and unitary transitions) are forcing councils to rethink how they use data. Yet many councils are still relying on legacy data systems that were never designed for today’s scale, speed, or expectations.
From on-premise data warehouses to fragmented reporting platforms, legacy data estates create hidden costs and limit the ability to deliver joined-up services. Below are the five most common legacy data challenges holding back UK local government and why modernisation is becoming unavoidable.
Technical Debt in Data Systems Consumes Scarce Capacity
Many councils are running legacy data warehouses hosted on ageing infrastructure. Over time, these environments accumulate technical debt: hard-coded ETL jobs, brittle integrations, undocumented logic, and manual fixes.
This leads to:
- High maintenance cost of legacy systems
- Constant firefighting when jobs fail overnight
- Heavy reliance on a small number of specialist staff
Instead of enabling business intelligence and business data analysis, teams spend their time keeping systems alive. A modern data stack reduces this burden by separating storage and compute, automating scaling, and reducing manual ETL maintenance.
Data Silos Prevent Joined-Up Services
Local government services rarely operate in isolation, housing, social care, SEN, finance, and safeguarding are deeply interconnected. But data silos in legacy systems make it difficult to build a single view of citizens, households, or service demand.
Siloed onsite data warehouses:
- Limit cross-departmental data warehouse analytics
- Create inconsistent metrics across teams
- Slow decision-making when joined-up insight is needed most
Modern cloud data platforms support governed sharing across departments while maintaining strict access controls a prerequisite for joined-up, citizen-focused services.
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Scalability Issues in Legacy Data Warehouses
Legacy platforms were designed for predictable workloads and small data volumes. Today, councils need to analyse growing datasets from case management systems to sensor data and external datasets.
Common issues include:
- Poor performance during reporting peaks
- Data warehouse performance issues when workloads increase
- Expensive infrastructure upgrades to scale on-prem systems
A cloud vs on-prem data warehouse comparison increasingly favours cloud migration, where compute can scale on demand without capital investment.
“Budget constraints mean councils need AI-enabled efficiency now, not in two years’ time. In practice, local authorities are choosing platforms that are quicker to implement and demand fewer specialist skills. That’s exactly why we’re seeing decisions like Westminster selecting Snowflake over alternatives that require larger teams and longer timeframes to reach value.”
Simon Tobias – UK Local / Regional Government Lead, Snowflake
Rising Costs with Limited Cost Visibility
Many councils underestimate the on-premise data warehouse costs they are carrying. Hardware refreshes, licensing, energy consumption, and specialist support all contribute to rising total cost of ownership.
Legacy environments often obscure:
- True data storage cost management
- Cost per report, dashboard, or dataset
- The opportunity for data infrastructure cost optimisation
Cloud migration enables transparent, usage-based costing, allowing councils to align spend with value and optimise over time.
Legacy Data Limits Analytics and AI Readiness
There is growing interest in predictive analytics and AI across local government, from demand forecasting to fraud prevention. But legacy data warehouses struggle to support advanced business data analytics, especially where unstructured data is involved.
Without data warehouse modernisation, councils face:
- Slow experimentation cycles
- Limited access to real-time or near-real-time data
- Increased risk when introducing automation
A modern cloud data platform creates the foundation for scalable analytics, governed AI adoption, and future-proof service improvement.
Moving Forward: From Legacy to Modern Data Foundations
For local authorities, data warehouse migration is no longer just a technical upgrade, it’s a strategic enabler. Moving from an on-premise data warehouse to a cloud data platform supports better services, reduced technical debt, and improved resilience through organisational change.
The key is starting pragmatically: identify high-impact use cases, modernise in phases, and focus on outcomes rather than technology alone.
Explore the wider context in our 2026 UK Public Sector Data Trends report.
