Estimating the economic level of water losses in Casablanca: Toward efficient and sustainable urban water management

Estimating the Economic Level of Water Losses (ELWL), defined as the loss level at which further control is no longer economically justified under the adopted cost–benefit framework, often relies on manual curve fitting and visual intersection selection, while economic assessments of water losses remain limited in Morocco and North Africa. This study developed an automated Python-based framework for estimating ELWL in Casablanca's 6867 km drinking-water distribution network. The framework combined water-balance analysis, performance indicators, cumulative cost and benefit calculations, automated model selection, and numerical root-finding. Network efficiency was expressed as the percentage of system input volume remaining after total water losses. Between 2016 and 2020, real losses decreased by about 5.5%, whereas apparent losses increased by about 49.7%, showing that total losses cannot be managed through leakage control alone. The procedure selected a quadratic control-cost model and an exponential benefit model, producing an ELWL of 40.67 m 3 /customer/year, which closely matched the manual estimate of 40.7 m 3 /customer/year. The observed 2020 loss level was 35.65 m 3 /customer/year, 12.34% below ELWL, indicating that further uniform reduction may not be financially balanced under the model assumptions. Sensitivity analysis showed that ELWL was mainly influenced by water-loss volume. The framework strengthens the limited evidence on economic water-loss assessment in Morocco and North Africa and provides utilities with a practical tool for targeting investments that balance economic efficiency, water conservation, and service priorities.