The transformation issue of water and land use in irrigated agriculture in Siberian regions remains insufficiently studied. The study of this issue, especially over a long period, is very relevant. From 1990 to 2020 the area of irrigated land in Siberia decreased from 526 thousand hectares to 334 thousand hectares. In some subjects of the federation, the irrigation area decreased by 2-2.5 times in the Republic of Khakassia, and in the Novosibirsk region, it decreased slightly. In 1990, 15.9 thousand hectares of irrigated land (i.e., 3% of all irrigated land) were not used in agricultural production largely due to soil salinization and waterlogging. In 2020, there were 6.8 thousand hectares of such land. It is necessary to increase the share of fodder crops in irrigated crop rotations to improve soil fertility as well as to increase the production of fodder and livestock products. Due to the write-off of the worst lands in some regions (Republic of Tyva, Tomsk region), there is an increase in the share of lands with a good reclamation condition and a decrease in the share of lands with an unsatisfactory condition. In general, the share of lands with the good ameliorative condition in the Siberian District has noticeably decreased, especially from 2010 to 2020. Lands equipped with a collector-drainage network are available only in the Altai Territory and the Omsk Region. The area requiring capital work to improve the technical level of irrigation systems has sharply increased (from 10–25% in 1990 to 80–90% in some regions in 2020). The authors found that the area of actually irrigated lands in Siberia progressively decreased from 461 000 hectares in 1990 to 64 000 hectares in 2020. The number of sprinkling machines and installations decreased by 17 times, and the volume of water consumption – by ten times. In recent years state support for entities engaged in mining on reclaimed lands has been strengthened.