Can Shade Fabrics Help Prevent Water Loss?

 

Currently, many growers use ground cover fabric made from black polypropylene to help reduce the amount of water that’s lost from the soil where they’re growing plants. However, using ground cover fabric can pose issues for some growers who want, or have to, turn their crops over each year. When they need to rotate what’s growing on the land, using ground cover fabric can end up becoming more costly and burdensome.

Fortunately, shade fabric may be the solution that growers need.

How Can Shade Fabric Help?

While shade fabric is most commonly used as a way to reduce sunlight and heat for plants and animals, it has also been shown to help prevent water loss. By reducing how much sun hits the ground, it can reduce the amount of water that’s normally lost through evaporation and transpiration during months of high heat.

During times of drought, this is especially helpful, as growers can apply water where needed and potentially lose less moisture when using a shade system over the plants. According to a study done by the University of Southern Queensland, using suspended shade covers is “reported to reduce evaporation up to 85%.”

Practical Uses of Shade Fabric to Prevent Water Loss

Cities have begun using this concept to help prevent water loss in reservoirs. Back in 2015, 96 million black polypropylene shade balls were put in an LA reservoir to help save water by reducing evaporation in an area that suffers from the impacts of severe drought. This creative endeavor not only helped to prevent water loss, but it was a cost-effective solution as well.

The Director of Water Operations with Los Angeles Department of Water and Power, Richard Harasick, explained:

“This is a huge reservoir. It’s 126 acres and to put any kind of cover or roof on it would have made it the largest covered reservoir, at least in the United States, to the tune of $300 million or $400 million. So by putting the shade balls on, we solved all of our water quality problems and saved $250 million.”

This same concept can be useful for those who take advantage of natural resources through rain collection systems. Many water storage bins are made of polypropylene or polyethylene since the materials can withstand the elements. Depending on where the bin is kept, it could be exposed to excessive amounts of sunlight and heat, causing some of the water to evaporate.

Since the bin is usually enclosed, some of the vapor may turn back into liquid with cooler temperatures, but no bin is airtight, so some water vapor will escape, resulting in water loss. Taking the idea from the polypropylene shade balls in the LA reservoir and utilizing it on a smaller scale, someone could cover a water storage bin with a black shade fabric that would prevent sun and heat from hitting the bin, reducing water evaporation. This would be particularly useful during times of drought or in areas with traditionally low rainfall levels.

 

To learn more about the effect of shade covers on the evaporation rate of reservoirs, read this study from the Spanish Journal of Agricultural Research.