This paper presents technological innovations based on new hydraulic insulating materi- als, the use of which in reservoir construction will essentially reduce construction costs by up to half. New polymer-mineral based waterproofing materials N1 and PMM can be used to construct inexpensive reservoirs. In particular, a thoroughly mixed mixture of soil taken from the bottom of a reservoir or other substrate with PMM material at a ratio of 30 grams PMM to one kg of the substrate, laid on the bottom of the reservoir with a thickness of at least 10 cm, and tamped down to a layer of 7 cm or less, will withstand at least 2.5-3 atm pressure of water column. A similar result can be obtained if a 5 cm thick layer of N1 material is laid on the reservoir bottom, together with pebbles to reduce the cost of the proposed solution.