📋 Case Study

Calibration of Lagos Metropolitan Water Network

Persistent model–field mismatch (>25% pressure error) due to undocumented pipe replacements and unaccounted demand growth

🏗️ Project Overview

Nigerian utility upgrading aging infrastructure across 12 zones

🎯 Challenge

Persistent model–field mismatch (>25% pressure error) due to undocumented pipe replacements and unaccounted demand growth

🔧 Design Approach

Two-phase calibration: (1) top-down demand multiplier tuning per zone; (2) bottom-up roughness adjustment using 87 pressure loggers and 14 flow meters

📐 Design Diagram

Calibration of Lagos Metropolitan Water NetworkZone 1Zone 2Zone 3Zone 4×1.32×1.45×1.58×1.62×1.68Demand Multiplier:CI Mains: C = 92 → 78PVC Laterals: C = 140 → 115Roughness (C-value):Challenge: >25% pressure error (undocumented pipe replacements, unaccounted demand growth)Sensors: 87 pressure loggers • 14 flow metersMain trunkZonal demandPipe roughness

AI-generated project design illustration

📐 Key Calculations

Zone Demand Multiplier

Measured Avg. Flow / Modeled Avg. Flow
Result: 1.32–1.68
Corrects for undocumented population growth and illegal connections

C-value Adjustment

Hazen–Williams recalibration via EPANET Solver
Result: C = 92 → 78 (CI mains), C = 140 → 115 (PVC laterals)
Accounts for tuberculation and biofilm accumulation

📊 Results

Pressure RMS error reduced from 27.4 m to 3.8 m; model validated across 92% of monitoring points; enabled predictive leakage hotspot mapping

💡 Lessons Learned

  • Field data granularity dictates calibration fidelity
  • Demand multipliers must be updated quarterly
  • Material-specific aging curves improve long-term model accuracy

Key Takeaways

  • 1Field data granularity dictates calibration fidelity
  • 2Demand multipliers must be updated quarterly
  • 3Material-specific aging curves improve long-term model accuracy