The history of the building is very long and marked by the Second World War. Due to disputes over the dam's design, its most favourable period for construction during the First Republic was lost. It was not until 1937 that the construction of the lock in Štěchovice was commissioned. The construction site was relatively narrow and inaccessible on the right bank, with a strong current, variable water levels and problems with freezing. Also, because navigation for rafts and ships had to be ensured, the whole construction was divided into three stages. Concrete batching plants were set up on both banks to produce the concrete mix, producing 186,000 m3 of concrete for the entire construction. The entire Štěchovice dam with the hydrocentre was put into operation in 1945.
The dam is straight, heavy, concrete, lined with granite blocks. It consists of a concrete body with five spillways of 20 m each. The height to the crown is 22,5 m and the width at the base is 20 m. The length of the dam is 124 m. The spillways were dimensioned for the flood of 1890 for the static calculation of the body load increased by 50% for safety reasons. The dam was subjected to such a flood in 2002. To protect the concrete structures, the entire spillway is lined with kicked granite masonry.
However, there has been no major enlargement. This is not only because of poorer accessibility, especially by motor vehicles, but also because of the cold water, even in the summer months. It is supplied by cold ground water taken from the Slap turbine and is shaded by high slopes for a relatively short stretch, so the water does not change its temperature much. Thanks to this, however, this valley, which has lost its famous Svatoyanské streams, has remained at least a little bit romantic. The rocky slopes are still illustrated by the original log cabins, tramp settlements, including their totem poles and sheriffs. From the Slap Dam to the Štěchovická River, a hiking trail runs along the left bank, leading in some places comfortably and in others along a rocky hillside with rock tunnels.