. Simulation and optimation methods is often used in management of water resources. In this journal, the methods are used to get method exploiting of water resources from accumulating Cimeta reservoir at River of Cimeta - West Java. Method Simulation is used to try various exploiting of amount of water required among others drinking water, irrigation and industrial start from year 2005 until 2030. From optimation method with linear program to target function of maximizing advantage and release yield advantage for year 2005 (Rp. 5,341,963,401.29), year 2010 (Rp. 5,502,992,697.29), year 2020 (Rp. 6,220,765,679.09) and year 2030 (Rp. 7,508,548,171.86). The increasing of benefit is got because there is increasing of water demand. The result of calculation optimation method with linear program is got that Cimeta reservoir is only reach optimum in 2010 because release is produced by Waduk Cimeta is not good enough to meet the demand water for domestic, irrigation and industry in 2020 and 2030. The method is used to determine the useful age of Cimeta reservoir is Trap Efficiency method which depend on comparison between capacity of storage reservoir (C) and inflow (I) annual of the reservoir.Capture efficiency of reservoir will decrease in line with the age, because capacity of reservoir will decreased by sediment filled. As known that capacity of storage (0.7996 x 106 m3) and annual sediment inflow (0.0777 x 106 m3) then determination useful age of reservoir to capacity of storage at elevation + 735 by various value Trap Efficiency at some percentages degradation volume of storage (ΔV= 5%, 10% , 20% dan 80%) indicate that the useful ofage is based on the time of filling storage by sedimen is 21.49 years at ΔV=5%, 21.337 years with ΔV= 10%, 20.641 years with ΔV= 20% and 19.038 years with ΔV=5%. So at various phase of persentage volume storage (ΔV) which is used is the biggest degradation phase that is ΔV= 5% with the useful age of reservoir is 21.49 years.