In the ecological management of deep-water lakes and reservoirs, how to efficiently supply oxygen to the oxygen-depleted bottom waters without disrupting the natural structure of the water body has long been a global challenge.

 

The Camanche Reservoir in California, USA, has provided us with a successful example of the application of ultra-nano-aerosol reoxygenation technology through three decades of continuous operation and monitoring.

I. The “Suffocation” Crisis of Deepwater Reservoirs

The Kamanche Reservoir is an important source of drinking water and a popular recreational area in central California. However, like many deep-water lakes and reservoirs, it suffers from seasonal thermal stratification. During the summer, the water column develops a stable thermocline, separating the warmer surface waters from the colder bottom waters and leaving the lower layer—known as the hypolimnion—deprived of oxygen.

 

This oxygen deficiency can trigger a series of ecological disasters, including the release of endogenous pollutants, the death of aquatic organisms, and the deterioration of water quality. Under anaerobic conditions, substances such as phosphorus, iron, and manganese stored in bottom sediments are released into the water body, accelerating eutrophication. The oxygen deficiency directly threatens the survival of cold-water fish species like salmon, disrupts the ecological balance, causes foul odors in the water, and increases the burden on wastewater treatment plants.

 

To address this issue, in 1996, the reservoir managers installed and began operating an ultra-nano-aerosol reoxygenation system to increase oxygen levels in the lower stagnant water layer.

II. Principle and Application of Ultra-Nano Aerosol Re-Oxygenation Technology

This technology isn't simply and crudely injecting air into the water; rather, it's a precise and efficient ecological engineering solution.

 

1. Achieving precise reoxygenation through “aerosol” delivery.

Deep-layer oxygenation—rather than surface aeration—employs an ultra-nano-aerosol reoxygenation device installed at the bottom of the Calamansi Reservoir in California, near the dam. An underwater electric pump draws water from the deepest part of the reservoir—where water quality is typically poorest—through a pipeline and mixes it with pure oxygen until all air bubbles are completely dissolved. The resulting cold, dense, oxygen-rich water, free of bubbles, is then reintroduced into the lower layer via openings in a diffusion pipe, reaching near-saturation levels. Since the density of the water discharged from the ultra-nano-aerosol reoxygenation device remains unchanged, the oxygenated water flows along the reservoir’s bottom, horizontally diffusing and oxidizing the sediments deposited above the bottom mud. This approach perfectly addresses the issue that conventional aeration methods tend to disturb stratification and harm cold-water organisms.

2. System Operation and Adaptive Management

Since its inception in 1996, the system has not remained static. Based on real-time water quality monitoring data, managers dynamically adjust the oxygen injection rate and depth. This adaptive management strategy ensures that the system operates at optimal efficiency under any hydrological and meteorological conditions, thereby achieving refined and intelligent water treatment.

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III. Over a decade of monitoring data bears witness to the ecological rebirth.

More than a decade of continuous monitoring has provided robust observational data on the effectiveness of this technology. The data show that the system has successfully maintained the dissolved oxygen concentration in the lower water layers above 5 mg/L, completely reversing the previous anaerobic conditions.

Soluble phosphorus concentrations in the surface water of the Kamancheh Reservoir before and after activation of the nano-aerosol device.

Pulse peaks occurred in both 1995 and 2001 due to brief shutdowns of the ultra-nano aerosol equipment. In both instances, after the ultra-nano aerosol equipment was restarted, phosphorus concentrations dropped significantly. This demonstrates that, with system intervention, endogenous pollution has been effectively controlled, thereby slowing down the eutrophication process at its source.

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IV. Core Advantages of Ultra-Nano Aerosol Re-Oxygenation Technology

The 30-year success story of the Kamanqi Reservoir fully validates the core advantages of ultra-nano aerosol reoxygenation technology in the management of deep-water lakes and reservoirs:

1. Directly targets the lesion, boasts high oxygen utilization, and is specifically designed to address deep-seated hypoxia.

2. Protect the natural stratification of water bodies and avoid disrupting the upper-layer ecosystem and cold-water habitat.

3. It can effectively control endogenous pollution at its source, achieving long-term improvements in water quality with a high cost-benefit ratio for operation.

4. It can be linked with online monitoring systems to achieve intelligent and refined operational management.

Conclusion

The case study of the Kamanqi Reservoir represents a “laboratory report” written in a real-world water body—a study spanning more than three decades. It demonstrates that the ultra-nano-aerosol re-oxygenation technology is both practical and feasible, providing a long-term, proven technical blueprint for lakes and reservoirs worldwide facing similar “deep-water” challenges. Moreover, it stands as one of the most effective and ecologically friendly approaches to addressing oxygen depletion in deep-water lakes and reservoirs.

Reference materials:

Hypolimnetic Oxygenation 4: Effects on Turbidity in Camanche Reservoir and Its Downstream Fish Hatchery

Hypolimnetic Oxygenation 6: Improvement in Fisheries, Hydropower, and Drought Management with Installation and Operation Costs at Camanche Reservoir, California, United States

Hypolimnetic Oxygenation 3: An Engineered Switch from Eutrophic to a Meso-/Oligotrophic State in a California Reservoir