Irregular territorial expansion is a constant problem among the residentes of Brazil, creating also conflicts with the environment and the public administration, which, in many cases, is unable to monitor and control the growth of occupations. The aim was to geo-reference in field, analyzing the illegal occupation and all degradation points in Açude Marcela-SE. The study was conducted in the vicinity of Marcela-SE dam through ortofotocartas, vector data of Digital Atlas Water Resources Sergipe and use of TRIMBLE GPS PRO-XR model for georeferencing of the properties in field, and environmental degradation points, the data being worked on Quantum GIS 2.2.0. It was observed a total of 53 rural properties, with seven lots of irregular occupation and 40 occupying the area of permanent preservation, which is absent of native vegetation. It was found also points in natura effluent disposal without operating wastewater treatment system areas with clay storage and disposal of pesticides. The use of geotechnology allowed the georeferencing of rural properties and environmental degradation points and can be used in territorial planning and monitoring the environmental quality of Marcela dam.