Purpose. To propose an approach that can be applied efficiently when selecting the coordinate system used in hydroelectric construction in Viet Nam. Methodology. The efficiency of the proposed approach is first demonstrated by comparing the relative reduction of distances between the Gauss - Kruger and 3-degree and 6-degree UTM projections. It is then proved with an experiment at a hydroelectric power in Viet Nam by comparing the reductions of distances estimated by the proposed approach and those computed from using the VN-2000 coordinate system that is frequently applied. Findings. The experimental results indicated that the proposed approach is more efficient in establishing the geodetic horizontal network in hydroelectric construction in Viet Nam with much smaller distortion in the geometrical size and shape of the network. Originality. This work is the first study on selection of the geodetic horizontal network in hydroelectric construction in Viet Nam based on the average height and the longitude of the center of the construction area. Practical value. The approach proposed in this work can be applied easily and efficiently in practical applications of hydroelectric power construction in Viet Nam, particularly in the areas with high altitude with reference to the ellipsoid as well as the areas located far away from the central meridians of the Viet Nam's VN-2000 reference system.