This polygon shapefile represents model simulated flood-inundation extents for the Muddy River, near Moapa Nevada. A flood frequency analysis was performed at USGS streamgage 09416000 - Muddy River near Moapa, Nevada, to estimate the 50, 20, 10, 4, 2, and 1-percent annual exceedance probability (AEP) flood streamflows. The flood-inundation extents for the 50-, 20-, 10-, 4-, 2-, and 1-percent AEP floods were simulated for the current levee location in 2019 and for the new levee location of the proposed restoration. One model simulation represents the levee at its current (existing) location in 2019 on the east bank of the river and referred to as ‘current conditions (2019).’ A second model simulation removes the existing levee and represents the new levee location farther away from the river on the east side of the proposed restoration area. The second model simulation is referred to as the ‘proposed restoration conditions.’ Both model simulations had the same flood-hydrographs, hydraulic structures, and roughness coefficients; however, the topography data used for each model simulation was adjusted to represent differing locations of the existing and proposed levees. Flood-inundation extents were simulated with a coupled 1-D- and 2-D unsteady hydraulic model in the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) computer program. Those locations where the water-surface was higher than the land surface were defined as inundated. The inundation polygons are named by AEP flow (50, 20, 10, 4, 2, 1-percent) and condition (current and proposed restoration).