Water Conservation with Managed Aquifer Recharge under Increased Drought Risk

Area of Science:

• Agricultural Economics
• Hydrology
• Water Resource Management

Background:

• Managed aquifer recharge (MAR) economic analyses often overlook impacts on crop choice and groundwater pumping.
• Successful MAR can lead to higher groundwater levels, influencing agricultural practices and water demand.

Purpose of the Study:

• To model the economic impacts of MAR on farm net returns in Eastern Arkansas.
• To assess the influence of drought frequency and severity on groundwater use and MAR effectiveness.
• To quantify water 'slippage' in MAR systems.

Main Methods:

• A landscape-level model was used to simulate 120 years of farm operations in Eastern Arkansas.
• The model incorporated MAR, on-farm surface reservoirs, crop selection, and drought impacts on groundwater use.
• Farm net returns were maximized under various MAR cost and drought scenarios.

Main Results:

• Drought frequency significantly impacts groundwater pumping and MAR utilization more than drought severity.
• Substantial MAR water slippage (32-75%) was observed, meaning only 25-68% of MAR water effectively raises groundwater levels.
• Despite slippage and MAR costs, farm net returns increased, and return variability decreased with MAR implementation.

Conclusions:

• MAR can enhance agricultural economic returns and stability in regions facing groundwater depletion and drought.
• Drought risk management is crucial for optimizing MAR strategies and agricultural water use.
• Addressing MAR water slippage is important for maximizing the efficiency of water resource management.