Project Summary:  Traditional approaches to reduce the risk of coastal and riverine floods include the construction of conventional infrastructure such as levees and floodwalls. Over the last decade there has been a push towards Engineering With Nature (EWN) and implementation of natural infrastructure (NI) (wetlands, barrier islands, coastal dunes, forest, riparian buffers) into resiliency and risk management planning to help reduce flood hazards rather than rely on conventional infrastructure alone. However, we do not know the scales and dimensions NI needs to be in order to produce a substantial reduction for a range of flood hazards and related risk. High-performance, high-fidelity, computer models of coastal and riverine floods provide a means to develop strategic and controlled digital environments to test how different NI features (and combinations) and their size can provide flood risk reduction.