Uttar Pradesh is one of the states in India where tremendous water development has taken place after independence for extension of irrigation facilities and fulfilling other requirements. At present state boasts to have about 87 % irrigated area while the national average is only about 49 %. Before five year plan period, irrigation potential created was 5.4 million hectares only, which is now more than 36 million hectares, though there is a huge gap between potential created and potential utilized. The net irrigated area also increased from about 3.2 million hectares to about 14.4 million hectares after independence. Thus, the state is now categorized as one of the highly irrigated states of India. After independence, drinking water, and industrial facilities also increased manifold in the state to fetch the growing demand of its population. With an increase in irrigation facilities crop productivity and food production also increased manifold in the state and now the state is one of the major contributors to the food basket of the Nation. In its endeavor for water development to meet the growing demand of the growing population, the state somewhere ignored the management aspects of water development and relied too much on groundwater as the state is comparatively rich in groundwater resource which is easily available and its abstraction is very easy and cheap in the state. The invention of low-cost pump sets in the 1980s started the tube well revolution in the country and Uttar Pradesh became the center of the tube well revolution. Though the state has a large canal network, irrigation is mainly dependent on groundwater. There are about 4 million tube wells and wells in the state providing 81 % irrigation supplies. Apart from this, groundwater is fulfilling about 80 % of drinking water requirements and 90 % of industrial demand. This has led to heavy exploitation of this precious natural resource. Due to excessive abstraction of groundwater, out of 820 developmental blocks, the water level is declining in 572 blocks, which indicates groundwater mining or abstraction of non-renewable groundwater in a majority of blocks. In most of the 653 major and medium townships in the state, groundwater levels are also declining at alarming rates as easy resource availability and access has encouraged mushrooming tube well construction activity. Rainfall pattern is also changing in the state due to climate change complications and rainfall is not a reliable source of water supplies now. In the last three decades, the annual average rainfall is continuously declining, triggering water crises in the state. River basins are water-short now indicating future water crises and call for demand-side interventions. Canal commands continue to face the problem of waterlogging while tail ends face the non-availability of water. The book discusses in detail the surface and groundwater availability and their development in the state, irrigation facilities, and effect on productivity due to extension of irrigation facilities, present and future availability of water, future needs, the status of water management interventions, present challenges such as declining rainfall, underutilization of irrigation potential, water scarcity, water quality, water laws, and governance, water efficiencies, etc