The following paper describes the design of a rainwater harvesting system for the CAMTAC industrial plant in Guelph, Ontario. The objective of this system is to provide an environmentally and economically sustainable way to reduce industrial water consumption. This design is comprised of a catchment area, a delivery network, a storage unit, and a control system. The catchment area is the area on CAMTACs plant roof where the rainwater will be collected. The delivery network is comprised of a series of PVC pipes that channels this rainwater into the PVC storage tanks inside the plant near the reverse osmosis filtration system. A mechanical control system is installed within the storage units to manage the levels of water consumption. The total cost of this design system is approximately $20 000, which corresponds to a payback period of 10 months.