In today’s climate crisis affecting much of the world, water and energy management has shifted from being an operational concern to a strategic priority. In regions where water stress is a daily reality, allowing stored water in reservoirs to be lost through evaporation is, financially speaking, a leakage of capital. This is where the installation of geomembranes as floating covers emerges as the most advanced and cost-effective technical solution.
SAI leads the implementation of floating cover systems that not only protect water resources, but also open the door to clean energy generation through biogas capture.
The Problem of Evaporation in Open Reservoirs
In arid or semi-arid climates, an open reservoir can lose a significant percentage of its annual volume due to evaporation. For agricultural or mining operations, this represents massive inefficiency. Beyond volume loss, evaporation concentrates salts and minerals in the remaining water, degrading its quality and increasing treatment costs.
Benefits of a Floating Geomembrane Cover
- Evaporation reduction: Up to 95% of evaporation losses can be eliminated.
- Algae control: By blocking sunlight, photosynthesis is prevented, eliminating algae growth without the use of chemicals.
- Protection against contaminants: Prevents dust, ash, and animal waste from entering the water.
Materials Engineering: HDPE or LLDPE for Covers?
For floating covers, material selection differs from bottom-liners. The cover must be flexible enough to rise and fall with water levels and extremely resistant to direct UV radiation.
At SAI, we typically recommend HDPE geomembrane with special thermal-resistance additives, or, in cases of complex geometries, linear low-density polyethylene (LLDPE) due to its higher elongation capacity. The durability of these systems depends critically on proper installation, as seams must withstand constant mechanical stresses caused by wind and water movement.
Biogas Capture: Turning Waste into Energy
In industrial and agro-industrial wastewater treatment (such as pig farms or food processing plants), floating covers serve an additional purpose: odor control and gas capture.
By installing a sealed cover over an anaerobic lagoon, generated gases—primarily methane—are trapped. SAI designs and installs gas collection systems beneath the membrane, allowing the biogas to be directed either to a flare for controlled combustion or, preferably, to a generator for electricity production.
The Challenge of Wind and Ballasting
One of the most common mistakes made by non-certified installers is underestimating wind forces. A cover without a proper ballast and venting system can behave like a giant sail, tearing perimeter anchors loose.
The SAI team precisely calculates wind loads and uses internal weighting and flotation systems that keep the membrane in contact with the water, minimizing the “flutter effect” that shortens geomembrane lifespan and durability.
Water and Energy Efficiency
Floating covers represent the final frontier in reservoir optimization. By choosing SAI for your geomembrane installation, you are investing in a technology that pays for itself through water savings and potential energy generation. In a world of limited resources, protecting your assets is not an option—it is a competitive necessity.
Frequently Asked Questions
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What maintenance does a floating cover require?
Primarily, removal of debris from the surface and inspection of rainwater drainage systems to prevent water accumulation that could submerge sections of the membrane. -
How long does it take to recover the investment (ROI)?
In regions with high evaporation rates and high water costs, ROI is typically achieved within 2 to 4 years. -
Can a floating cover support the weight of a person?
Although some covers are designed for maintenance access, walking on them is not recommended without special safety equipment and support rafts to avoid punctures.
