Photogrammetry was used to evaluate the distribution of wrinkles on three geomembranes made of high density polyethylene and polypropylene. Results are presented in terms of the geometry of wrinkles and relative position of the various wrinkles obtained in the HDPE geomembranes. In all cases wrinkles developed in two preferential directions, nearly normal to each other. The maximum height of wrinkles is about 0.1m with a maximum distance between wrinkles equal to 1.6 m. Lengths of wrinkles vary between 0.5 and 4 m, widths between 0.1 and 0.8 m. Results obtained were used to feed a mathematical model of quantification of flow rates through composite liners in case of two interacting wrinkles. Results obtained with the polypropylene geomembrane could not be interpreted.