1. It is necessary to distinguish the coefficient of effective area of action of the seeping waterα2and coefficient of spatial work of the permeable foundationα2,f. The physical significance of these coefficients is different: The coefficientα2(2) is a unique geometric characteristic of the flow region of the rock mass and figures into the formulas for determining the SFs (3)–(5); The coefficientα2,fdetermines the proportion of the horizontal SFs forming in the foundation and banks of the hydrostatic load on the reservoir bed. The coefficientα2,fis a unique energy characteristic of the flow region of the mass, giving an idea about the spatial distribution of the potential energy stored in the reservoir. 2. When determining the settlements of the foundation and structure during their monitoring it is necessary to take into account the absolute settlements of the fundamental bench marks of the geodetic network. The value of these settlements can be considerable. For example, the calculated absolute settlement of the fundamental bench marks at a distance of 2.9 km from the Sayano-Shushenskoe dam toward the lower pool was 17.9 mm in 1986. 3. The values of the coefficientα2,fof the permeable rock mass of the foundation and bank can be determined by measuring the relative settlements of the territory adjacent to the dam, the outer monitored boundary of which is at a distance of 2–3 km from the dam. For this purpose it is recommended to use the derivative of the functionΔU(x) in thex direction [d(ΔU)/dx]. 4. The values of the heads figuring in the formula (11) recommended by SNiP 2.06.06-85 should be taken in increments relative to the natural water level in the river that existed before creation of the reservoir. 5. The values ofα2,fof the foundation of the Sayano-Shushenskoe dam determined from the results of observations of settlements of the territory adjacent to the dam agree with the recommendations of SNiP. However, with consideration of the great importance of the accuracy of determining surface and seepage forces for ensuring the reliability of a planned structure, it is advisable to supplement the relevant article of SNiP with a more distinct regulation with respect to determination and assignment ofα2,f.