Lochsa Engineering provided the civil and flood control design for the 20-acre condominium towers site, as well as the design of the Clark County Regional Flood Control District (CCRFCD) master-planned storm drain to intercept and convey the Blue Diamond Wash-Middle Branch through the property. The majority of the site was designated by the Federal Emergency Management Agency (FEMA) as a floodplain (Zone AE/Floodway) for the Blue Diamond Wash. The project included hydrologic modeling of Blue Diamond Wash through the project site, hydraulic design for 1600lf of 28-ft x 7-ft cast-in-place Arch Culvert underground storm drain, and obtaining FEMA approval for the design through Conditional Letter of Map Revision (CLOMR) application. Upon the construction of the flood control facility, Lochsa Engineering removed the designated Special Flood Hazard Area (SFHA) through obtaining FEMA’s approval of a Letter of Map Revision (LOMR). The design efforts also included the civil, hydraulic and structural design of multiple drop inlets, junction and transition structures, confluences and headwalls. Civil design included two high-rise condominium towers, parking garage and exterior amenities. Infrastructure design included master planning utility corridors and “wet/dry” utilites for the towers and adjacent building pads.