Pressurization is used in treatment systems such as Wisconsin mounds, Low Pressure Pipe systems, recirculating sand filters, and pressure distribution in conventional systems to attain uniform distribution. While calculations used to determine the hydraulics for these systems are not complex, their application requires iterative calculations that add unnecessary cost to system designs. Computer spreadsheets are ideally suited for these iterative calculations since results are generated instantaneously upon each minor modification to the system configuration. The Pressure System Design Spreadsheet (PSDS) enables designers to configure asymmetrical systems with up to 26 laterals and 50 orifices per lateral. Lateral elevation and lengths may vary. Friction losses and orifice discharge are calculated using the Hazen-Williams equation and the orifice discharge formula. Output from the PSDS includes: system discharge, head losses for the delivery pipe, manifold, laterals, lateral segments, and total system losses, pump capability, and system configuration details. System configurations developed with the PSDS program are completed quickly compared to iterative hand calculations and are consistent with empirical calculations.