A graphical test is presented to check if recorded annual maximum flood data for a group of gauging stations in a region belong to a common parent distribution (P). The test compares the observed at site L-coefficient of variation (Lcv) with its sampling distribution. The latter is obtained by generating synthetic sequences from an assumed parent distribution (P). A group of sites is deemed to be homogeneous if the observed Lcv, treated as an order statistic, lies within its sampling distribution. The proposed test has been applied to annual maximum flood data from Tanzania to delineate the country into 12 homogeneous regions.