The increasing number of disasters around the world calls for a new direction in building the networks; this direction is known as disaster-resilient networks. In this paper, we consider the effect of post-disaster traffic on the core network performance. We evaluate the network blocking during single node flooding with different flood sizes. Then we study four mitigation approaches to maximally serve the traffic floods using the excess capacity, traffic filtering, rerouting and Differentiated-Services. The results show that the studied approaches reduce blocking by 50% in the worst cases.