This job shows a daily tank model that simulates the hydrological cycle in a watershed. An economic component is coupled to tank model for water valuation in the different variables of the hydrological cycle. In this case the exercise is done for groundwater and subsurface components. Each component is evaluated for both water storage and flow. Also this job includes the concept of rescaled adjusted range (RAR). This concept permits to compute the water regulation capacity through a reservoir which can deliver an output flow equals to the multiannual average flow without incurring a deficit. RAR helps to value the three different components of simulated streamflows in a watershed: Groundwater flow, subsurface flow and direct-runoff flow. The water pricing model permits to obtain the resource demand curve and elasticity for allocation or demand management.