Isla Hispaniola (Haiti and the Dominican Republic), one of the poorest regions of the planet, has repeatedly been hit by catastrophic natural disasters that caused incalculable economic losses and killed thousands of people. One striking example is the disastrous flood-event that occurred in the transnational basin of River Soliette on May 24th, 2004. The event was produced by a severe tropical storm originated over the Caribbean Sea from an intense low-pressure system, and killed over 1000 Haitian and Dominican people, wiping out a number of rural villages. The General Direction for Development and Cooperation of the Italian Department of Foreign Affairs funded through the Istituto Italo-Latino Americano (IILA, www.iila.org) an international cooperation initiative (ICI), coordinated and directed by the University of Bologna. The initiative involved Haitian and Dominican institutions and consisted in two main components: (a) institutional capacity building on flood-risk management and mitigation measures and policies; (b) hydrological and hydraulic analysis of the May 2004 flood event aimed at formulating a suitable and affordable flood-risk mitigation plan. The second component of the cooperation is the main focus of this paper and in particular, starting from some logistical and technical constrains, a topographic survey based on GNSS technology that enabled us, in a short time, to survey river cross sections and construct Digital Elevation Models for two areas where to conduct numerical hydraulic modelling and to pre-design hypothetic flood-risk mitigation measures. The paper reports and discusses the main phases of the project.