The M2M Thematic Programme funded 17 scientific investigation projects leading to more unified physical understanding of fluid flow distributions in heterogeneous rock. The programme focused on developing an understanding of the relationships between measured and modelled subsurface fluid flows spanning the range of spatial and temporal scales relevant to fluid resource management. The programme was motivated by the growing recognition that assumptions of uniformity at certain scales are inadequate for extrapolating fluid behaviour both in time and space. Research spanning a wide spectrum of observation and simulation scales was undertaken by the programme which can be divided into four themes: (1) understanding the natural processes which lead to scaling relationships between size and magnitude of rock and flow heterogeneity; (2) quantification of essential fluid flow properties and their spatial pattern from measurements;(3) identification of appropriate statistical models and scaling laws describing rock property heterogeneity and fluid-rock interactions in geological media;(4) understanding the relationships between rock property distributions and flow model parameter distributions.