Wadi El-Rayan Protected Area (WERPA) is considered a model protectorate and an ecological restoration success. Development and mismanagement of Wadi El-Rayan vulnerable water resources could lead to the depletion of two artificial lakes and large scale deterioration of ecosystem health. We quantify the environmental value of preserving WERPA by applying the water-food-energy nexus approach and the concept of nonmonetary opportunity cost. Three output indicators: agriculture, aquaculture and net energy production are selected to assess the value of different ecosystem health conditions under three water management scenarios. STELLA object oriented modeling environment has been used to simulate the scenarios that led to favorable, satisfactory, and critical ecosystem health conditions. The results demonstrated that the economic output that could be realized by reaching the favorable condition has twice the value of the acceptable condition. (C) 2017 European Regional Centre for Ecohydrology of the Polish Academy of Sciences. Published by Elsevier Sp. z o.o. All rights reserved.