HYDRAS is equipped with nine mobile rainout shelters, each able to cover an area of 300 m2. In combination with an automatic irrigation system, this makes it possible to precisely control the quantity of water that reaches the plants. The system enables investigation of crop responses to drought at different stages during crop development. The rainout shelters are mobile and can be moved to one of three different positions, each representing a plot of 300 m2. The design of the system allows implementation of a crop rotation system, while an area of more than 5,000 m2 is available for experimentation each year.