In this demo, we present a Virtual Institution for water rights negotiation (virtual mWater). We explain its implementation using the Virtual Institution Execution Environment (VIXEE). Main features of the infrastructure are i) the causal connection between Virtual Worlds and Electronic Institutions, ii) the automatic generation and update of the VIs' 3D visualization and iii) the simultaneous participation of users from different virtual world platforms. We show the result of generating a 3D representation of virtual mWater from its specification and an example of human immersion within the institution.