Fault tolerance and periodical changes of the network topology are two important attributes that should be carefully designed in Wireless Sensor Networks (WSN). In this paper we propose a new routing protocol for improving fault tolerance of WSN which takes into consideration the measurement accuracy requirements (expressed as a lower limit on k-coverage) and network performance. The main idea of the k-coverage problem is to schedule the sleeping time of sensors in order to preserve their energy and maximize network lifetime. The proposed routing protocol offers a protection against link and node failures by computing k disjoint paths. It also takes into account the changes of the network topology caused by the scheduling of sensor sleeping.