: River Formation Dynamics (RFD) is an evolutionary computation method based on copying how drops form rivers by eroding the ground and depositing sediments. Given a cost-evaluated graph, we apply RFD to find a way to connect a given set of origins with a given destination in such a way that distances from origins to the destination are minimized (thus improving the quality of service) but costs to build the connecting infrastructure are minimized (thus reducing investment expenses). After we prove the NP-completeness of this problem, we apply both RFD and an Ant Colony Optimization (ACO) approach to heuristically solve it, and some experimental results are reported. Key Words: River Formation Dynamics, Ant Colony Optimization Algorithms, Heuristic Algorithms, NP-hard problems.