Objectives of this article is to put at the disposal of the administrators a risk map for the contamination of surface waters in the watershed of the Oued Martil dam, allowing them to reduce the possible damages susceptible to affect them as a result of a poor management due to the lack of information. Such a map is the result of the superposition of vulnerability maps in the contamination of superficial waters and that of the danger map. The contamination danger map of the watershed of the Oued Martil dam lets appear the "Low" class correlative to the activities of the agriculture, Douars, careers, oil-works and the road, represents a percentage of 50,27%. Almost the same percentage is attributed to the very low "class"; this one coincides with the main valley and the unwooded grounds (naked lands). These two classes are ill-assorted throughout the study area. The considered contamination vulnerability map in this study is that elaborated following the application of DKPR method, considering the natural characteristics of the environment having an effect on the contamination of surface waters. About the contamination risk map of the studied dam shows the predominance of the low degree classes which extend more than 98 % of the surface of the concerned watershed. They reflect the low effect of the anthropological activities distributed on the surface of our watershed on the waters contamination.

This work present a document allowing a good management territorial of the watershed of Martil river situated in the Wilaya of Tétouan, (North of Morocco) to preserve the good quality of the water of the dam. Such document is developed by applying the DKPR method to map the degree of vulnerability in the contamination surface water by means of a software GIS. The obtained map shows the dominance of the high and moderate classes. The first one covers the central part of the of the studied area on approximately 50 % of the total surface, while the moderate class disparate on all the watershed while being more concentrated towards the Southwest and the East, concern almost 42 % of the studied area. Let us indicate that the extreme East of the watershed nearly 8 % of the total surface is weakly protected against the contamination of its superficial water resources.

A surface water contamination vulnerability mapping has been carried out to contribute to water quality protection of the Martil river dam. The applied methodology (ESU) depends on three parameters i) density of the hydrographic network ii) soil hydrologic potential and iii) agricultural drainage. The vulnerability degree is a result of a typological interaction between these three parameters through there different possible combinations Results indicate that high vulnerability classes are shown within almost 85 %of the catchment area. Otherwise, some southern, northern and south western areas (14 %) are of mean vulnerability, while a very restricted area (1 %) shows low vulnerability to contamination.