The HELP (Hydrologic Evaluation of Landfill Performance) Model was used to evaluate the hydrologic behavior of a series of one-, two-, and three-layer cover designs for municipal solid waste landfill cover designs were chosen to isolate the effects of features such as surface vegetation, thickness, soil type and hydraulic conductivity of the layers on the average annual runoff, cover percolation, evapotranspiration, and lateral drainage. The results of the evaluations are presented in numerous bar charts to supplement the tables and schematics. Soil hydraulic conductivity was one of the most important design features in controlling cover percolation for all covers tested. Minimal cover percolation and runoff were the two main criteria used to select the four best cover designs. The report also includes a brief discussion of four other aspects of landfill cover design; animal and vector control, subsidence, gas control, and cost.