Since mesoscale numerical models do not have the spatial resolution to directly simulate the fluid dynamics and thermodynamics in and around urban structures, urban canopy parameterizations are sometimes used to approximate the drag, heating, and enhanced turbulent kinetic energy (tke) produced by the sub-grid scale urban elements. In this paper, we report on efforts to modify the urban canopy parameterization found in the HOTMAC model to include the effects of residential, industrial/commercial, and downtown/city center landuse. We investigate the effect of the urban canopy parameterizations by turning the parameterizations on and off for simulations performed in the Los Angeles basin. Preliminary results indicate that the urban canopy parameterizations impact the mesoscale flow field, reducing the magnitude of wind speed and changing the magnitude of the sensible heat flux and tke in the metropolitan area. Further efforts will concentrate on the interaction between the heat island, sea-breeze, and mountain-induced slope flows found in the LA basin.