In this article on the basis of archival materials and scientific literature the information on the state of the irrigation system, which was the basis of agriculture in the Uzbek SSR during the years of Soviet power, is presented. The article highlights the changes in the irrigation system related to the agrarian policy pursued by the Soviet authorities. In particular, the creation of the cotton monopoly led to further expansion of the irrigation system. Indeed, the acquisition of new land and the establishment of cotton fields led to the expansion of the irrigation system. As a result, new canals were built and old ones repaired in many regions of the country. Although water structures allowed the development of protected areas, these works also had negative consequences for the population of the republic. During the years of Soviet power, problems related to labour protection in industry were repeatedly raised. But this issue was not given due attention. The use of various chemical fertilisers to increase the yield of cotton in the republic had a negative impact on the health of the population. Due to this, various diseases spread among the population. Residents were forcibly involved in the construction and repair of irrigation facilities.