Infrastructure Leakage Index (ILI) KPI

The Infrastructure Leakage Index (ILI) serves as a critical performance indicator for water utilities, quantifying the extent of water loss due to leakage.

High ILI values can indicate inefficiencies in infrastructure management, leading to increased operational costs and reduced service reliability.

By tracking ILI, organizations can identify areas for improvement, enhance operational efficiency, and align strategies with financial health goals.

Effective management of leakage not only conserves resources but also improves customer satisfaction and regulatory compliance.

A focus on ILI can drive significant ROI by minimizing waste and optimizing resource allocation.

How Infrastructure Leakage Index (ILI) Connects to Your Strategy

Infrastructure Leakage Index (ILI) sits in one KPI group, Water and Wastewater Utilities, where it ranks sixteenth of seventy-four members. The group leads with compliance and reliability: Water Quality Compliance Rate holds the top priority, followed by Water Supply Reliability Index, Regulatory Compliance Score, and Wastewater Treatment Compliance Rate. Just ahead of ILI in the same group sit its closest relatives, Water Loss Percentage and Non-Revenue Water (NRW). The three form a loss cluster that customers should read together: Water Loss Percentage states the raw physical loss, NRW adds commercial losses and unbilled consumption, and ILI normalizes real losses against what the network could theoretically achieve, which is what makes it useful for comparing performance across utilities.

ILI carries the internal process perspective on the balanced scorecard, and it behaves as a leading indicator. Leakage performance moves before the outcomes the group ranks highest, because water lost in the network eventually shows up as strained supply, higher production cost, and regulatory exposure. There is also a genuine tension inside the group. The fastest lever for improving ILI is pressure management, since real losses fall when operating pressure falls, yet aggressive pressure reduction pulls directly against the Water Supply Reliability Index, the group's second-ranked member. Customers at the edges of the network feel reduced pressure and availability first, so a team chasing a better leakage index can quietly erode the reliability measure the group treats as more important. Managing both together, rather than optimizing ILI in isolation, is the discipline this KPI group enforces.

Measuring Infrastructure Leakage Index (ILI) in Practice

ILI is a ratio of current annual real losses to unavoidable annual real losses, so the honesty of the index depends entirely on what feeds each side. Start with the numerator. Real losses can be derived top down from a water balance, where system input volume minus authorized consumption and apparent losses leaves real losses as the remainder, or built bottom up from minimum night flow analysis and component-based estimation of bursts and background leakage. The two approaches rarely agree on the first pass. Decide which one governs and use the other as a reconciliation check, because a numerator that floats between methods makes every period-over-period comparison suspect. In the top-down path, system input volume metering accuracy dominates: an under-registering source meter silently deflates real losses and flatters the index, while assumptions about apparent losses, meter under-registration and unauthorized consumption, shift volume between the real and apparent categories without changing anything physical in the ground.

The denominator is just as easy to distort. The unavoidable annual real losses reference, UARL, is calculated from mains length, service connection counts, the length of private pipe, and average operating pressure. That means asset register quality is a measurement issue, not just an engineering one. Stale connection counts, unrecorded mains, and a lazy assumption about average pressure all move the index without any change in actual leakage. Pressure deserves particular care: because UARL is pressure-corrected, a utility that reduces pressure changes both its real losses and its reference level, and the index will not move the way a raw loss volume would. Track the inputs, network length, connection counts, and measured average pressure, with the same rigor as the losses themselves.

It is worth remembering why the metric is built this way. Raw leakage volumes and simple loss percentages are not comparable across systems that differ in size, connection density, and operating pressure, so a sprawling low-pressure rural network and a dense high-pressure urban one cannot be judged on the same volume figure. ILI removes that structural noise by scaling each system against its own theoretical floor. Segment it by pressure zone or district metered area rather than reporting a single system-wide figure, since a healthy average can hide zones where leakage run times and repair backlogs are quietly growing.

Common Pitfalls

Many organizations overlook the importance of regular infrastructure assessments, leading to undetected leaks that inflate ILI values.

• Failing to invest in modern leak detection technology can result in prolonged water loss. Traditional methods may miss hidden leaks, causing unnecessary operational costs and resource waste.
• Neglecting employee training on leak management practices leads to inconsistent responses. Without proper knowledge, staff may not effectively identify or address leaks, exacerbating the issue.
• Ignoring data analytics can prevent organizations from identifying patterns in leakage. A lack of quantitative analysis hinders informed decision-making and strategic alignment.
• Overlooking customer feedback regarding service interruptions can mask underlying issues. Engaging with customers helps in identifying problem areas that may not be visible through standard metrics.

Improvement Levers

Enhancing the ILI requires a proactive approach to infrastructure management and data utilization.

• Invest in advanced leak detection systems to identify and address issues promptly. Technologies like acoustic sensors can significantly reduce response times and minimize water loss.
• Implement regular training programs for staff on best practices in leak management. Knowledgeable employees are better equipped to recognize and resolve issues quickly.
• Utilize data-driven decision-making to analyze leakage patterns and prioritize repairs. A robust reporting dashboard can provide insights into areas needing immediate attention.
• Engage with customers to gather feedback on service quality and interruptions. This information can inform operational adjustments and enhance overall service delivery.

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OKRs That Use Infrastructure Leakage Index (ILI)

The Water and Wastewater Utilities KPI group gives ILI a direct home in its OKR material, under the objective "Improve infrastructure efficiency to minimize water loss and operational waste." In the group's own example, lowering the Infrastructure Leakage Index by upgrading pipeline maintenance protocols serves as a key result alongside reducing Water Loss Percentage through better leak detection and repair, cutting Non-Revenue Water (NRW) through enhanced metering and theft prevention, and raising Water Treatment Plant Reliability. The group's rationale is that ILI quantifies leakage severity and guides targeted asset management, which is exactly the role it should play as a key result: the pressure-corrected, length-normalized check that tells you whether loss reduction reflects genuine network improvement rather than a favorable year.

The group's best practices add a useful constraint: address Water Loss Percentage and Non-Revenue Water together, since that pairing targets both physical leaks and unauthorized consumption at once. A practical OKR framing for a utility facing the aging infrastructure and high leakage the group's OKR guidance describes is to set the infrastructure efficiency objective, keep ILI as the directional key result for real losses, and let NRW and Water Loss Percentage carry the commercial and volumetric sides. Any target a team attaches to ILI should be treated as an illustrative goal grounded in its own baseline and pipe replacement budget, not as an external benchmark.

See OKR Examples for Water & Wastewater Utilities

KPI Categories

This KPI is associated with the following categories and industries in our KPI database: