Factors affecting the cost of managed aquifer recharge (MAR) schemes

Managed aquifer recharge (MAR) is an important technique for improving groundwater recharge and maintaining aquifer levels. There are many examples from around the world that demonstrate the advantages of managed aquifer recharge. Despite the numerous benefits and demonstrated advantages of MAR, uptake has been lower than expected. The financial and economic performance of MAR is a key determinant of its global uptake. There are few studies of the financial characteristics and performance of different kinds of MAR schemes. This study contains an analysis of financial data from 21 MAR schemes from five countries. Although MAR schemes are highly heterogeneous, it is possible to draw some conclusions about factors that affect the costs of storing water underground and recovering it for use. The costs of MAR schemes vary substantially. Schemes using infiltration and spreading basins using untreated water are relatively cheap. Schemes using recharge wells, bores and expensive infrastructure are relatively costly. When advanced water treatment is needed, this involves significant extra costs. Other key factors that affect MAR scheme costs include the range of objectives to be met, frequency of use of the scheme, hydrogeological conditions that affect infiltration rates and well yields, and the source and end use of water stored underground. Priorities for further research include additional disaggregation of capital and operating costs and inclusion of a wider range of scheme types, sources of water and countries.