In the last years floods of small and large rivers have shown all the problems of our environement. In the mean time droughts treads every year many people.

Here several experiences of watersheeds management are shown, they are groupped in:

- fight against desertification;
- land defence from floods;
- water uses: irrigation and human consumption.

Hydraulic works described here are built in different area of the word but they are all designed for watersheed management. Each work is conceived for a very specific fonction in the watersheed management.