Assessing the Feasibility of Managed Aquifer Recharge for Irrigation under Uncertainty

Muhammad Arshad,Joseph Guillaume,Andrew Ross

doi:10.3390/w6092748

Abstract

Additional storage of water is a potential option to meet future water supply goals. Financial comparisons are needed to improve decision making about whether to store water in surface reservoirs or below ground, using managed aquifer recharge (MAR). In some places, the results of cost-benefit analysis show that MAR is financially superior to surface storage. However, uncertainty often exists as to whether MAR systems will remain operationally effective and profitable in the future, because the profitability of MAR is dependent on many uncertain technical and financial variables. This paper introduces a method to assess the financial feasibility of MAR under uncertainty. We assess such uncertainties by identification of cross-over points in break-even analysis. Cross-over points are the thresholds where MAR and surface storage have equal financial returns. Such thresholds can be interpreted as a set of minimum requirements beyond which an investment in MAR may no longer be worthwhile. Checking that these thresholds are satisfied can improve confidence in decision making. Our suggested approach can also be used to identify areas that may not be suitable for MAR, thereby avoiding expensive hydrogeological and geophysical investigations.

Highlights

Water demand continues to grow in order to maintain food security and drinking water supplies, while supplies remain limited from conventional sources
We focus on cross-over points as one possible means of addressing uncertainty in the cost-benefit analysis of managed aquifer recharge (MAR)
The results show that MAR using the basin infiltration method will yield 11% more value than surface storage of irrigation water

Summary

Introduction

Water demand continues to grow in order to maintain food security and drinking water supplies, while supplies remain limited from conventional sources. Future water security is threatened in many places, as most suitable locations for large surface storages have already been used [1] and ground water is often being withdrawn at unsustainable rates [2,3,4]. Among other options of water supply augmentation, such as water recycling, desalination etc., storing more water underground appears to be a potential solution to achieve future water supply goals. Water shortages can be eased by storing surplus water underground during wet periods for later use during dry periods. Storage of surplus water in aquifers can help minimize evaporative losses and help irrigators to adjust to surface water variability during droughts, provided that

Methods

Results

Discussion

Conclusion