Sediment loads from construction sites can be a significant environmental pollutant. Models are useful tools that can be used to evaluate the effectiveness of different sediment control plans. The WATER (Watershed Assessment Tool for Environmental Risk) model has been developed specifically to simulate erosion and sediment processes at construction sites. Risk is assessed in this model from ensemble statistics obtained from many years of simulated weather conditions. The user has a choice of different modeling methods from which the most appropriate is selected based on site characteristics, availability of parameters, and expertise of the user. An important subcomponent of the WATER model is the prediction of climate conditions. This stand alone subcomponent is called the WINDS (Weather Inputs for Nonpoint Data Simulations) generator and is also briefly discussed.