shade balls
Jun 04

The Comprehensive Guide to Shade Balls: An Innovative Solution for Water Conservation

In recent years, the innovative use of shade balls has captured the attention of environmentalists, scientists, and the general public alike. These small, black plastic spheres have proven to be a simple yet highly effective solution for various water conservation and quality issues. This blog post delves into the purpose, benefits, design, applications, specifications, and environmental considerations associated with shade balls.

shade balls

What Are Shade Balls?

Shade balls, also known as “bird balls” or “conservation balls,” are small, hollow plastic spheres that float on the surface of water bodies. They are typically made from high-density polyethylene (HDPE), a durable and UV-resistant plastic. Measuring about 4 inches (10 cm) in diameter, these balls are designed to cover large surface areas of reservoirs, ponds, and lakes.

Shade balls are typically black because this color absorbs sunlight, preventing light penetration into the water. This is crucial for their function in reducing evaporation and controlling algae growth. The balls are filled with water to keep them from blowing away, and their lightweight yet robust construction allows them to withstand environmental conditions for years.

Purpose and Benefits of Shade Balls

1. Water Conservation

One of the primary purposes of shade balls is to reduce water evaporation. By covering the surface of the water, shade balls significantly decrease the exposure of the water to direct sunlight and wind, both of which contribute to evaporation. This is particularly crucial in arid regions and during drought conditions where water conservation is of utmost importance.

Studies have shown that shade balls can reduce water evaporation by up to 90%. This is a significant saving, especially in large reservoirs where the volume of water lost to evaporation can be substantial. The deployment of shade balls in the Los Angeles Reservoir, for instance, was estimated to save 300 million gallons of water annually. This water-saving measure not only helps conserve a precious resource but also reduces the need for water from other sources, which can be costly and environmentally damaging.

2. Algae Control

Algae thrive in warm, sunlit water. By blocking sunlight, shade balls inhibit the growth of algae, thereby helping to maintain a healthier aquatic environment. Algae blooms can be harmful, producing toxins and depleting oxygen levels, which negatively impact aquatic life.

The presence of shade balls can reduce the temperature of the water surface by several degrees, creating a less favorable environment for algae growth. This reduction in algae growth not only improves the water quality but also reduces the need for chemical treatments, which can have their own environmental impacts. Additionally, by preventing algae blooms, shade balls help maintain the aesthetic and recreational value of water bodies.

3. Water Quality Improvement

Reducing algae growth directly contributes to better water quality. Additionally, in reservoirs used for drinking water, shade balls can minimize the formation of harmful chemical reactions. For instance, they help prevent the formation of bromate, a carcinogenic compound that can form when bromide and chlorine interact under sunlight.

In drinking water reservoirs, the presence of shade balls can lead to a significant reduction in the formation of disinfection by-products (DBPs), which are harmful compounds formed during the water treatment process. By reducing sunlight penetration, shade balls help maintain the quality of drinking water and protect public health. This is particularly important in regions where the quality of source water is already compromised.

4. Wildlife Protection

Shade balls also play a role in protecting wildlife. They deter birds and other animals from landing on the water surface, thereby reducing the risk of contamination from bird droppings and other sources.

Bird droppings can introduce pathogens and nutrients into the water, leading to water quality issues and potential health risks. By covering the water surface, shade balls create a physical barrier that deters birds and other wildlife from accessing the water. This not only helps protect the water quality but also reduces the risk of wildlife-related conflicts, such as birds getting entangled in water treatment infrastructure.

Design and Implementation of Shade Balls

design odf shade balls    shade balls design


Shade balls are typically made from high-density polyethylene (HDPE), chosen for its durability and resistance to UV radiation. This ensures that the balls can withstand prolonged exposure to sunlight and harsh environmental conditions.

HDPE is a preferred material for shade balls because it is non-toxic, resistant to chemicals, and has a long service life. The material’s UV resistance is particularly important because it prevents the balls from degrading under constant exposure to sunlight. This durability means that shade balls can remain effective for many years without needing replacement, making them a cost-effective solution for water conservation.

Size and Color

The standard size for shade balls is around 4 inches (10 cm) in diameter. Black is the most common color because it absorbs sunlight effectively, though other colors can be used depending on specific requirements.

While black shade balls are the most effective at reducing evaporation and controlling algae growth, other colors may be used in specific applications. For example, white or light-colored balls may be used in situations where it is desirable to reflect sunlight and reduce water temperature. The choice of color and size can be tailored to the specific needs of the water body being treated.


Shade balls are deployed by simply pouring them onto the surface of the water. They naturally spread out to form an even layer, covering the surface and creating a barrier against sunlight.

The deployment process for shade balls is straightforward and can be completed quickly. In large reservoirs, shade balls can be deployed using specialized equipment that distributes the balls evenly across the water surface. Once deployed, the balls require minimal maintenance, making them a practical and efficient solution for water conservation and quality management.

Specifications of Shade Balls

MaterialHigh-Density Polyethylene (HDPE)
DiameterApproximately 4 inches (10 cm)
ColorPrimarily black, other colors available if needed
WeightTypically 40-50 grams each, can be filled with water
UV ResistanceHigh, prevents degradation from sunlight exposure
LifespanGenerally 10 years or more, depending on conditions
Coverage1 square meter (10.76 square feet) requires 70-75 balls


Key Features:

  • Durability:Resistant to chemical corrosion and physical impacts
  • UV Protection:Special additives provide long-term UV resistance
  • Eco-Friendly:Made from recyclable materials
  • Temperature Range:Suitable for use in temperatures ranging from -40°C to 60°C (-40°F to 140°F)
  • Maintenance:Low maintenance requirements, easy to clean if necessary

Notable Applications

Los Angeles Reservoir

One of the most well-known applications of shade balls was in the Los Angeles Reservoir. Faced with severe drought conditions, the Los Angeles Department of Water and Power deployed millions of shade balls to reduce water evaporation and improve water quality. This project garnered significant media attention and highlighted the effectiveness of shade balls as a water conservation measure.

The Los Angeles Reservoir project involved the deployment of 96 million shade balls, covering an area of 175 acres. This large-scale deployment demonstrated the potential of shade balls to provide substantial water savings and improve water quality. The success of this project has led to increased interest in the use of shade balls in other regions facing similar water conservation challenges.

deployment of shade balls

Other Applications

Shade balls are also used in various other contexts, including industrial water storage tanks, irrigation ponds, and stormwater treatment facilities. Their versatility makes them suitable for a wide range of water bodies and conservation needs.

In industrial settings, shade balls are used to cover water storage tanks and ponds to prevent evaporation and contamination. This is particularly important in industries where water is a critical resource, such as food processing and manufacturing. In agricultural applications, shade balls can help reduce evaporation from irrigation ponds, ensuring that more water is available for crop irrigation. In stormwater treatment facilities, shade balls can improve the quality of stormwater runoff by preventing algae growth and reducing the formation of harmful compounds.

Environmental Considerations

Plastic Waste

While shade balls offer numerous benefits, their environmental impact must be considered. At the end of their life cycle, shade balls need to be properly managed to prevent them from contributing to plastic waste. Recycling programs and proper disposal methods are essential to mitigate this issue.

The use of HDPE for shade balls ensures that they can be recycled at the end of their useful life. Recycling programs should be established to collect and process shade balls, ensuring that they do not contribute to plastic pollution. Additionally, efforts should be made to develop biodegradable or more environmentally friendly materials for shade balls to further reduce their environmental impact.

Wildlife Impact

Ongoing research is necessary to ensure that shade balls do not negatively affect local wildlife and ecosystems. While they deter birds from landing on water surfaces, it is important to monitor their long-term impact on various species and habitats.

Studies should be conducted to assess the impact of shade balls on local wildlife, particularly bird populations. While shade balls are effective at deterring birds, it is important to ensure that they do not disrupt important feeding or nesting behaviors. Monitoring programs should be established to track the impact of shade balls on wildlife and to make any necessary adjustments to their use.


The production and deployment of shade balls should be evaluated for their overall sustainability. This includes considering the energy and resources required for their manufacture and transportation.

Efforts should be made to minimize the carbon footprint of shade ball production and deployment. This can include using recycled materials for manufacturing, optimizing transportation logistics, and exploring alternative deployment methods that reduce energy consumption. By considering the full life cycle of shade balls, it is possible to maximize their environmental benefits while minimizing their impact.

Technical Development Process of Shade Balls Cover

Introduction to Sunshade Balls

Sunshade balls, initially known as bird balls, were designed to prevent birds from landing on toxic tailings ponds generated by mining operations. The airport also uses them to prevent birds from being attracted to nearby drainage pools, thereby reducing collisions with aircraft.

Los Angeles Department of Water and Electricity (LADWP) Initiative

Since mid-2009, LADWP has placed approximately 400,000 balls in the Ivanjo Reservoir to prevent the formation of the carcinogenic chemical bromate, which forms when sunlight interacts with naturally occurring bromine and added chlorine to prevent algae growth. The original version of LADWP focused on water conservation, aiming to last five years until the Griffith Park project completion. The reduction in evaporation is estimated to save approximately 1.1 billion liters (290 million US gallons) of water within a year.

Environmental Protection Agency (EPA) Regulations

In 2014 and 2015, according to the US EPA’s surface water treatment regulations, LADWP placed 96 million sunshade balls on its largest reservoir, Las Virgins, which required coverage of large treatment reservoirs. LADWP indicates that in addition to reducing evaporation, they also reduce UV radiation byproducts and algae growth. These balls avoided 1.7 million cubic meters of water evaporation during their deployment from August 2015 to March 2017. The lifespan of the balls is ten years, and the plastic may be reused thereafter.

Material and Design

The sunshade balls used in the Los Angeles project are made of high-density polyethylene (HDPE) and carbon black additives to protect the plastic from ultraviolet radiation. Adding carbon black can also prevent the formation of bromate, which is a suspected human carcinogen. They have a diameter of about 4 inches (10 centimeters) and are partially filled with water to avoid being blown by the wind. HDPE plastic is commonly used in food and beverage containers and water distribution pipelines.Evolution of Sunshade Balls

shade balls evolution

GenerationFeaturesWeightCoverage RateUsage DefectsService Life
First GenerationInternal hollow structure40g91% (116 per m²)Poor wind resistance, easy to move, high transportation costs, loss in strong winds10 years
Second GenerationWater-injection technology to increase weight240gIncreased transportation cost, risk of breakage and leakage, difficult to pass customs
New Generation HexagonalPatented unique hollow hexagonal designOver 98%Over 20 years
New Generation AutomaticUnique double-layer structure, automatically injects and drains water880g99%Over 20 years

Key Improvements

First Generation:

  • Lightweight, hollow design.
  • Limited wind resistance and high movement.
  • High transportation costs.

Second Generation:

  • Increased stability with water-injection.
  • Higher transportation costs and risk of leakage.

New Generation Hexagonal:

  • Advanced design with high coverage rate.
  • Enhanced wind resistance, reducing transportation costs.

New Generation Automatic:

  • Advanced automatic water injection and drainage.
  • Excellent wind resistance and thermal insulation.
  • Significant savings in transportation costs.


The evolution of sunshade balls demonstrates a continuous improvement in design, stability, and cost-efficiency, with each generation addressing the limitations of the previous ones. The advancements in the new generation provide enhanced performance and a longer service life, making them a more sustainable and effective solution for water conservation and environmental protection.


Shade balls are an innovative and efficient solution for sedimentation in water and wastewater treatment processes. Their compact design, high efficiency, and versatility make them an attractive option for a wide range of applications. By understanding the working principles, design features, applications, and benefits of IPCs, engineers and operators can make informed decisions to optimize their water treatment processes.

As we continue to face challenges related to water scarcity and quality, innovative solutions like shade balls will play a crucial role in ensuring the sustainable management of our precious water resources. By implementing shade balls in reservoirs, industrial water tanks, irrigation ponds, and stormwater treatment facilities, we can significantly reduce water evaporation, improve water quality, and protect aquatic ecosystems. Continued research and development will further enhance the effectiveness and sustainability of shade balls, ensuring that they remain a valuable tool for water conservation and environmental protection.

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