Enhancing agricultural water resource management: Colour coding system for water distribution systems

This paper proposes a colour coding methodology for agricultural water distribution systems to strengthen wastewater characterisation and regulatory alignment. Colour coding systems are widely used in other industries. There is no standardised framework for agricultural water colour-coding that ensures perceptual clarity and regulatory acceptance. This limits consistency and reliability in classification. To address this gap, existing standards and practices were reviewed to identify limitations in the classification, collection, storage, recycling, reuse, and disposal of wastewater in agriculture. This study develops and validates a framework by integrating existing standards, perceptual differences (ΔE), and common colour associations. The colours were validated in the LAB colour space, with all values exceeding 10, indicating that the colours are readily distinguishable when printed on white paper or viewed digitally. Two case studies, an intensive livestock facility and a winery, demonstrate the practical application of the system in real-world settings. The engineering consultancy EnviroAg Australia Pty Ltd has implemented these colour codes across its technical and engineering documentation for clients nationwide. The framework achieved complete observed approval, with a 95% confidence interval for the true success probability ranging from 0.82 to 1.00, demonstrating its reliability and practical robustness. The methodology improves interpretive accuracy, reduces ambiguity, and enhances consistency in planning, auditing, and communication among stakeholders. It also considers users with colour vision deficiencies and supports optional integration with the ColorADD system to improve accessibility. Overall, the approach strengthens agricultural water resource management and provides a scalable framework for broader governance and regulatory integration.