Water is regarded as a precious resource, except when it becomes an environmental liability in the form of stormwater runoff. Fortunately, rainwater and stormwater harvesting provide the opportunity to capture the value of this runoff water. Incorporating rainwater and stormwater harvesting into a stormwater treatment train provides overall volume reduction and a potable or non-potable water source. Advanced treatment trains that start the design at the roof vs. ground level will be emphasized. Rainwater harvesting provides the opportunity to intercept and use the water prior to the formation of heavily polluted stormwater. When properly pre-treated the roof collected water provides an excellent source of water that is relatively easy to treat with traditional water treatment technologies and to meet end use water quality requirements. In most jurisdictions this water can be utilized for both indoor and outdoor applications. Both the initial financial viability of the system and the long-term success of the system depend on making educated design choices and choosing projects that are the right fit for rainwater harvesting. The financial success and the overall success of a system are also dependent on maintenance costs, which are a product of initial design. A rainwater harvesting or stormwater harvesting system should be designed to protect water quality and designed with maintenance in mind. The long-term success of a system is directly related to the owner's ability to maintain the system and minimize the need for maintenance. Properly designed systems are also able to achieve more than one objective. Offsetting potable water demand, reducing storm water volume and downsizing other site utility infrastructure are possible. When advanced predictive technology is coupled with the properly sized system for multiple indoor and outdoor uses, the ability to have projects with favorable paybacks are greatly enhanced. Several successful projects at various scales will be discussed along with suggestions on improvement of designs.