Since the dowsing technique is neither scientifically recognized nor understood in its functioning, however spectacular an isolated project success is not sufficient to warrant its further implementation without further discussion. For this reason, GTZ tried to provide more data to contribute to a clarification of the performance of the referred method, realized on three different levels.

• The dowsing competence of an expert appointed by GTZ, Dipl.-Ing. Hans Schröter, was checked within a large scientific research program. A detailed final report of the investigation has been published [2]. It contains all practical procedures and results of the project, performed by a team of 14 scientists from 9 different institutions situated in and around Munich; the financing and control of the study was executed by the German Ministry for Research and Technology, along with another scientific group appointed by the Ministry. A series of rigorous tests showed that Schröter was, amongst some 50 tested persons, the most successful participant and his dowsing talent could be proven with a great statistical significance.

• GTZ examined the speculation that the dowsing technique may also be of practical usefulness in other representative field programs, namely with respect to the increase of success rates. The results obtained up to now are contained in the following report: despite all possible objections, these results lead us to the conclusion that the said speculation is largely corroborated by the facts.

• Within a framework of cooperation between GTZ and a project team from Munich who participated in the above mentioned dowsing investigation, it was agreed to adopt a more scientific approach with regard to relevant future GTZ projects. This includes a field test of particular measuring devices and detailed discussions amongst specialists in the field of earth sciences, regarding the dowsing technique and the corresponding results obtained from GTZ projects. Of course, it cannot be expected that an extremely complex and historically developed problem, such as dowsing in conjunction with its immediate environment, may be satisfactorily solved within a short time and rendered acceptable on a general basis. Nevertheless, it clearly appears that this technique has been gaining more importance for particular, well specified tasks [2]. Former experiences already showed that it could be gainfully and reproducibly implemented in the field of geohydrology, provided that some careful precautions and controls were considered [3].

One of the aims of this report is to provide more information, by means of practical and well-documented examples, about this poorly known technique and, thereby, to provide a rational basis for future discussions. To underline the possible significance of this subject, a preliminary attempt is made to assess the presented results although a more general and final evaluation may only be made after the completion of future, specially designed and purely scientific studies of sufficiently large scale.

In any case, and at the present time, a variety of outlined examples from GTZ projects and other reports suggest the relevance of the recommendation that the success of water resource development measures in special arid areas may be increased, sometimes quite significantly, when appropriately selected dowsers are implemented. For example, we report on projects with success rates above 80% — results which, according to responsible experts, could not be reached by means of classical methods, except with disproportionate input. The final aim should be the scientific explanation of this technique and its technical simulation, so that adequately sophisticated instruments would perhaps be suited to replace the "detector"-function of appointed dowsers. Such efforts can be traced back as far as 60 years, but could not, till now, be followed with all the possible and available technical methods.