One of the major challenges facing modern human civilization is climate change. This study documents the lessons learned from improving water management and producing advisories to improve water use efficiency in village irrigation tanks in selected cascades in the Dry Zone of Sri Lanka. Primary data for the study were obtained from farmers and farmer organizations. The irrigation systems were equipped with water depth gauges in the tanks and rain gauges in the command area, and daily readings were taken by the farmers. Actual water use was estimated by using these readings and long-term averages of evaporation while approximating seepage and percolation losses in a spreadsheet water balance model. The daily water balance was also used to identify recording errors. A methodology to calculate the cultivable area using tank storage, forecasted rainfall, and long-term evaporation losses were also developed. The water management advisories produced from this information included, cultivable area reference to water availability, water use efficiency in the respective tanks, measures to improve data recording, irrigation duty, and measures to optimize the cultivable area each season. The results show that irrigation duty in Yala season ranged from 3.40 to 4.70 acre-feet/acre, while it ranged from 2.35 to 3.55 acre-feet/acre in the Maha season. However, the results of the study have confirmed that the efficiency of water use in many lakes during the dry season (Yala) is very low, and for this reason, it is appropriate to provide water management advisories. The study recommends the distribution of water on regular irrigation intervals, the alternating wetting and drying method, having drought-resistant and short-term crops and varieties, parachute farming, inception land preparation with rain, promoting collectivism method, using appropriate strategies for dissemination of agro-met advisories and weather forecast ground level and capacity building of farmer organizations and monitoring hydrological data.