A recent University of California Riverside study presents a promising new approach to water capture, storage, and distribution in California. The study highlights the challenges California agriculture faces due to environmental regulations, water shortages, and growing competition amid the climate crisis.
In California, agriculture accounts for 40% of all water and 80% of consumed water. This “historic water right” has disrupted community development and environmental flows. To mitigate these conflicts, a different strategy is necessary to satisfy both agricultural and public water demands.
Issues to Address:
- Evapotranspiration-Induced Droughts: As temperature increases and atmospheric moisture decreases, irrigation needs rapidly climb. The resulting water consumption worsens demands and scarcity.
- Estimated Changes in Water Availability: Low precipitation and anthropogenic forcing in California have impacted water supplies for years. Relying on reservoir storage may prove insufficient during future irrigation seasons.
- Rising Sea Levels: Saline intrusion is a major concern for coastal areas relying on groundwater for irrigation. Rising sea levels can also increase salinity in the Sacramento-San Joaquin Delta (SFE-SSJD), an area providing water to the south.
California already has an underground groundwater aquifer infrastructure that has been overpumped within the last few decades. Depleted aquifers can cause land subsidence, resulting in cracked roads and structures. Moreover, California simply lacks the storage capacity to hold water, potentially leading to overflow into the ocean and flash floods.
To mitigate the effects of these concerns, the researchers suggest diverting water to aquifers below the Central Valley and coastal plain areas. This water storage method lowers the risk of scarcity due to the evaporation and overflow associated with dam and/or reservoir usage.
Managed aquifer recharge (MAR) offers a viable solution to additional water capture. The California Department of Water Resources reported an annual average of roughly 2,000 hm3 of existing infrastructure is available for MAR efforts. Additional space could boost recharge opportunities in many areas, especially Sacramento Valley. However, proper management requires reliable and regular monitoring of aquifer withdraws or injections.
Additional Suggestions:
- Wastewater Recycling: Wastewater reuse is another important conservation method to further develop. The study suggests Coastal California is the most promising location for water recycling.
- Water Trading: An expanded water market could enhance water management flexibility by accommodating geographic shifts and reducing drought-related shortfalls. Market design, third-party impacts, stakeholder investment, and transaction costs must improve before this industry can thrive.
- Sustainable Agriculture Practices: Efficient agricultural methods are also pivotal for water conservation. For example, diversified cropping systems aid in effective water management while supporting biodiversity, carbon storage, and ecosystem services. Longer crop rotations or integrated livestock designs are other beneficial adaptations.
In the end, California agriculture can benefit from the reinforcement of aquifer infrastructure, water recycling, adaptive cultivation methods, and desalination. The research also supports water trading as a means of reallocating supplies to reduce shortfalls.
