Home / Environment / Millions of Balls Saved LA Water Supply
Millions of Balls Saved LA Water Supply
1 Jul
Summary
- 96 million plastic shade balls conserve water by reducing evaporation.
- Balls block sunlight, preventing bromate formation in drinking water.
- Project cost $34.5 million, a cost-effective water management solution.
In August 2015, Los Angeles began deploying 96 million hollow, 10-centimeter plastic spheres across its reservoir, a project later completed as the world's largest shade ball initiative. These durable, HDPE balls were designed to float freely, covering approximately 175 acres. Their primary purpose was to combat severe drought conditions by drastically reducing water evaporation, with LADWP estimating annual savings of around 300 million gallons.
Beyond water conservation, the shade balls served a critical public health function. By blocking sunlight, they prevented a chemical reaction that could form bromate, a potential carcinogen, in the drinking water. This measure was essential for meeting strict environmental regulations. The balls also limited algae growth, deterred birds, and reduced debris, further enhancing water quality and simplifying reservoir maintenance.
The shade ball project proved to be a remarkably cost-effective solution. Its total cost was approximately $34.5 million, significantly less than building a permanent cover. While initially puzzling to observers, the balls demonstrated a practical and environmentally beneficial approach to urban water management. As reservoir infrastructure improved, many balls were eventually removed and recycled, their service life of about 10 years concluded.
