The assessment of water quality is critical for environmental monitoring, public health, and resource management. This chapter explores the various physical analysis methods employed for the quantification of surface water and groundwater quality. This study focuses on the fundamental physical parameters such as temperature, pH, turbidity, electrical conductivity, Total Dissolved Solids (TDS), Dissolved Oxygen (DO), salinity, flow rate, water level, suspended solids, colorimetry, and radiation absorption and scattering. Each method’s principles, instrumentation, and application in both field and laboratory settings are meticulously reviewed. Key instruments include thermometers, digital pH meters, turbidimeters, Secchi discs, conductivity meters, TDS meters, DO meters, refractometers, flow meters, water level loggers, and colorimeters. The paper emphasizes the importance of regular calibration and maintenance of these instruments to ensure accuracy and reliability. Furthermore, it discusses the advantages and limitations of field-based versus laboratory-based analyses, highlighting the need for precise data collection and interpretation through statistical and geospatial methods. By providing a comprehensive overview of physical analysis techniques, this chapter aims to enhance the understanding and application of these methods in monitoring and managing water quality effectively.