The key issue in the pre-rehabilitation period is choosing a proper planning scale.
The project should cover an area large enough to reduce boundary effects and address
at least some sources of disturbances of the system, and what controls them, in an efficient way. The area should also enable proper monitoring of rehabilitation results and the achievement of intermediate objectives, which is crucial during the rehabilitation project. In the case of failure, the necessary actions should be planned to correct the problems. The evaluation should also include verification of performance indicators, whether they appear to be insufficient or inappropriate considering the project goals.