A multi-period planning approach for water reuse and regeneration networks in Eco-Industrial Parks (EIPs) is presented. The objective of the optimization problem is to determine the lowest network cost design for such systems, by taking into account an entire planning horizon. A source-to-sink mapping approach has been proposed to formulate the multi-period planning problem. Water sources can either be allocated to water sinks, treatment units or discharged to environment. Freshwater streams and treated water are made available to mix with water sinks to enable reuse between plants. Waste water is allowed to be discharged into environment at threshold contaminant levels. The problem has been illustrated initially with two-stage centralized treatment unit, then by considering a hybrid treatment setup consisting of both centralized and decentralized options. The results obtained indicate considerable cost reductions, when compared to those developed separately for each individual period. Moreover, a decrease in the complexity of the water networks has also been observed, when simultaneously considering the entire planning horizon.