Water is a critical resource for the electricity sector; particularly for hydropower generation; which relies on accurate and reliable hydrological data for efficient operation and planning. The measurement; estimation; and reporting of hydrological variables—such as river flow; reservoir levels; and turbine discharge—are essential for managing water resources; optimizing energy production; ensuring regulatory compliance; and supporting grid reliability. Colombia is experimenting a significant transformation in the electricity sector; with ambitious goals for increasing renewable energy sources levels in the national grid; including solar; wind; and maintaining hydropower energy. As the country increase its variable renewable energy sources (VRES); accurate and granular weather and hydrological data becomes a critical enabler for ensuring energy sufficiency; grid stability and efficient operation. The transition to a more sustainable and resilient energy system requires real-time and high-resolution hydrological and meteorological data to improve forecasting; integrate renewable energy sources; and enhance water resource management under changing climatic conditions. The current regulation associated with hydropower generation (CREG Resolution 025 of 1995) establishes a daily hydrological data reporting timing. However; daily timing for hydrological reporting may not be enough for energy planning under high climate variability scenarios; especially in the context of a system with a considerable component of hydroelectric generation with no regulating reservoirs (minor plants or under 20MW despatching). In the context of the energy transition; CREG Resolution 060 of 2019 establishes requirements for reporting operational meteorological data associated with solar and wind power generation with high temporal resolution. In that sense; existing measurement and reporting systems vary widely across power generation technologies (solar; wind and hydro); with differences in instrumentation; data quality; reporting frequency; and uncertainty levels. These discrepancies can lead to an impact in energy planning; safety operations; and regulatory oversight. In order to enhance transparency; accuracy and consistency in the sector; and given these challenges for the safe and reliable system operation under high variability and climate change scenarios; there is a pressing need to establish standardized guidelines for measuring; estimating; and reporting hydrological variables to ensure high-quality; reliable; and comparable data across the sector.