Dams and dams can be just huge sizes. For example, in some Alpine valleys the similar constructions can reach the level of clouds and do of the rivers of the lake by extent in several dozen kilometers.
1. The main difference of dam from dam is that dams are filled from stone, the earth and gravel (while dams construct from concrete or reinforced concrete). Do the lower part of dam very thick as it has to maintain water pressure. To prevent penetration of water through dam walls, do its core of very dense material, for example, from clay. Surely strengthen the base and condense up to the depths because otherwise there is risk of undermining of dam and leak of water on underground way.
2. At construction of dams and dams it is extremely important not to allow disappearances of the river. For this purpose prior to construction jobs lay for it the new course on which it will flow throughout all time of construction. If you carry out works in the narrow valley where there is no opportunity to build the new course, then make special tunnel on which water will be goes, passing construction site. If it is not possible to bypass the site after all, then you build dam gradually and extremely carefully, with each step dewatering via new auxiliary channels.
3. Build dam so that during floods there was possibility of switching to other mode. Surplus of water has to be dumped from dam rear side by means of system by-pass channels - it will help to save all system from possible damage. To extinguish force of the falling water, use construction from powerful concrete blocks. Will help to be saved from the destructive force of floods as well power plants. If at once several power plants are constructed one after another, then they take away part of water by means of stores, thereby preventing flooding of nearby settlements and flood.