Water conservation in irrigation can increase water use
Frank A Ward1, Manuel Pulido-Velazquez
1Department of Agricultural Economics and Agricultural Business, New Mexico State University, Las Cruces, NM 88003, USA.
Summary
Water conservation policies in irrigated agriculture may not save water. Adopting efficient irrigation can reduce return flows and aquifer recharge, potentially increasing water depletions. Real savings require better tracking and rewards for reduced water use.
Area of Science:
- Environmental Science
- Agricultural Science
- Hydrology
Background:
- Growing populations and climate change increase demand for water in agriculture.
- Irrigated agriculture is the largest global water consumer.
- Policies promoting water-conserving irrigation are common but their effectiveness is debated.
Purpose of the Study:
- To analyze the impact of water conservation policies on irrigation water use and actual water savings.
- To test the hypothesis that promoting water-saving irrigation technologies increases water availability for other uses.
- To provide an integrated assessment of water conservation in the Upper Rio Grande Basin.
Main Methods:
- Integrated basin-scale analysis incorporating biophysical, hydrologic, agronomic, economic, policy, and institutional factors.
- Evaluation of various water conservation policies within the Upper Rio Grande Basin.
- Modeling the effects of efficient irrigation technologies on water use and availability.
Main Results:
- Water conservation subsidies are unlikely to reduce water use in many river basins.
- Efficient irrigation technologies can decrease beneficial return flows and limit aquifer recharge.
- Policies targeting reduced water application may inadvertently increase overall water depletions.
Conclusions:
- Current water conservation policies may not guarantee real water savings.
- Effective water conservation requires institutional, technical, and accounting reforms to track and reward reduced water depletions.
- Policies should focus on reducing depletions rather than just diversions or applications to ensure water savings.
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