Electric power system (EPS) is an integral part of infrastructure systems. Ensuring its resiliency to extreme weather events and natural hazards is crucial to protect the safety, economy and public health. Recorded and projected data show an increase in the frequency and severity of extreme weather events and natural hazards attributed to a changing climate. It is critical to ensure the integrity of the aging infrastructure systems and to promote environmental justice by shrinking the energy-equity gap to lower power outages in disadvantaged communities. An important aspect is the resiliency interdependency of EPS to other critical infrastructure systems, an aspect that has been escalating due to rapid urbanization and technological developments. The main objective of this research is to quantitatively evaluate the resilience of levee-protected power grid to flooding in a changing climate and adapting a strategy to enhance the resilience of power grid. Thus, this study first establishes a methodological and multi-disciplinary framework by integrating climate science, hydrology, and EPS analysis to study (I) how climate change affects recurrence intervals of flooding, (II) how the integrity of levees will be affected by changes in flooding patterns, (III) how these changes affect the resilience of an EPS located in levee-protected areas, and (IV) how to improve the resilience of the EPS while reducing the energy-equity gap. The proposed framework is applied to some IEEE standard test systems overlaid on a levee-protected area in Northern California. First, a link-based resiliency analysis is performed using the direct current optimal power flow (dc-OPF) method applied to the IEEE-24 standard test system. Then, a node-based resiliency analysis is carried out employing the IEEE 118-bus test system. The system resiliency is assessed for pre-flooding, historic flooding, and projected future flooding scenarios using two representative climate pathways (RCP). Finally, an optimal adaptation strategy using the placement of distributed energy resources (DERs) is delineated using a modified IEEE 30-bus test system to reduce flooding-induced power outages, prioritizing disadvantaged communities by minimizing energy inequity among the communities. Results of this study reveal that the adaptation plan can reduce the risk of power outages, improve environmental justice and the resilience of power networks. The findings of this study can contribute towards more resilient EPS under a changing climate.