On recent trip, I couldn’t help noticing that farmers and government are still doing SFA to reduce evaporation from dams and ponds.

Working through the engineering, I quickly came to to the conclusion that man-made windbreaks are the way to go.

Consider the alternatives:

• Floating surface layer – chemicals
  This is either poisonous or edible. Neither is good for stock or wildlife.
• Floating surface layer – foam particles
  Ditto, and is easily blown off into the surrounding environment.
• Windbreaks using trees
  These are extremely effective at stopping the wind, but their roots sop up water which is lost by transpiration

Most of the evaporation is caused by wind rather than sunlight. As you will know if you try drying clothes on the clothes line. Or if you dry your hands in a public restroom using a Dyson airblade.

For man made windbreaks, it is well known that a solid fence is not the answer because it creates both strong recirculating air currents and strong winds along the length of the fence. A specially engineered porosity is the way to go. Too little porosity (like a cyclone fence) and the wind goes straight through with negligible hindrance.

Windbreaks are now being used in mining to stop dust blowing around, which is sort of the same process as wind-induced evaporation. These are metal and built on the large scale.

You’ve probably seen plastic wind fences set up on the small scale to stop windblown sand erosion on beaches or snow movement on snowfields.

A wind fence on two sides of a farm dam could reduce evaporation by up to 80%. As well as providing a little bit of shade for stock as they drink.

My question is this. If you had a farm with a water supply – dam or creek – what would you make a windbreak from? Wood, steel, aluminium or plastic?

FWIW Shade balls

have you considered shade balls?

https://www.learningliftoff.com/the-science-of-using-plastic-shade-balls-during-the-california-drought/

dang

You really ballsed that up PP.

Witty Rejoinder said:

You really ballsed that up PP.

give me a break you windbag :p

https://www.youtube.com/watch?v=uxPdPpi5W4o

sibeen said:

https://www.youtube.com/watch?v=uxPdPpi5W4o

That’s a good vide apart from the gee wiz kid, leave it to the dude in the suit and tie son.

party_pants said:

have you considered shade balls?

https://www.learningliftoff.com/the-science-of-using-plastic-shade-balls-during-the-california-drought/

Using ‘shade balls’ in reservoirs may use up more water than they save

>>Preventing reservoir evaporation during droughts with floating balls may not help conserve water overall, due to the water needed to make the balls.

Co-author Dr Kaveh Madani, from the Centre for Environmental Policy at Imperial College London, said: “We are very good at quick technological fixes, but we often overlook the long-term and secondary impacts of our solutions. This is how the engineering community has been solving problems; solving one problem somewhere and creating a new problem elsewhere.”

The shade balls are made of a kind of plastic that requires oil, natural gas and electricity to produce, all of which require large quantities of water. Producing 96 million balls of standard 5mm thickness would use an estimated 2.9 million cubic metres of water. During their time on the reservoir, the balls are estimated to have saved 1.15 million cubic metres of water.

This is alongside other potentially negative effects on the water, such as affecting life in the reservoir or promoting bacterial growth. In addition, the balls’ production could have negative effects on the environment associated with water pollution or carbon emissions.<<

https://www.sciencedaily.com/releases/2018/07/180716114605.htm

PermeateFree said:

party_pants said:

have you considered shade balls?

https://www.learningliftoff.com/the-science-of-using-plastic-shade-balls-during-the-california-drought/

Using ‘shade balls’ in reservoirs may use up more water than they save

>>Preventing reservoir evaporation during droughts with floating balls may not help conserve water overall, due to the water needed to make the balls.

Co-author Dr Kaveh Madani, from the Centre for Environmental Policy at Imperial College London, said: “We are very good at quick technological fixes, but we often overlook the long-term and secondary impacts of our solutions. This is how the engineering community has been solving problems; solving one problem somewhere and creating a new problem elsewhere.”

The shade balls are made of a kind of plastic that requires oil, natural gas and electricity to produce, all of which require large quantities of water. Producing 96 million balls of standard 5mm thickness would use an estimated 2.9 million cubic metres of water. During their time on the reservoir, the balls are estimated to have saved 1.15 million cubic metres of water.

This is alongside other potentially negative effects on the water, such as affecting life in the reservoir or promoting bacterial growth. In addition, the balls’ production could have negative effects on the environment associated with water pollution or carbon emissions.<<

https://www.sciencedaily.com/releases/2018/07/180716114605.htm

>>Federal rules mandate that all bodies of drinking water open to the air be covered. Floating covers provide more of a complete barrier from both sunlight and airborne contaminants, says Harasick. The shade balls will only remain at Los Angeles Reservoir, and that’s because it would be cost-prohibitive — to the tune of $250 million — to install a floating cover on the 175-acre reservoir, which holds a total of 3.3 billion gallons of water, enough water to fill the Rose Bowl five times. At 36 cents a pop, the 96 million plastic balls covering the surface have a lifespan of 10 years and require almost no maintenance aside from occasional rotation. In addition, Harasick adds, “we are experiencing cost savings in the reduced use of chlorine because the shade balls have reduced the amount of algae growth requiring treatment.” The LADWP also estimates they’ll see 300 million gallons in water savings with the shade balls.<<

https://www.governing.com/topics/transportation-infrastructure/gov-shade-balls-water-quality.html

PermeateFree said:

PermeateFree said:

party_pants said:

have you considered shade balls?

https://www.learningliftoff.com/the-science-of-using-plastic-shade-balls-during-the-california-drought/

Using ‘shade balls’ in reservoirs may use up more water than they save

>>Preventing reservoir evaporation during droughts with floating balls may not help conserve water overall, due to the water needed to make the balls.

Co-author Dr Kaveh Madani, from the Centre for Environmental Policy at Imperial College London, said: “We are very good at quick technological fixes, but we often overlook the long-term and secondary impacts of our solutions. This is how the engineering community has been solving problems; solving one problem somewhere and creating a new problem elsewhere.”

The shade balls are made of a kind of plastic that requires oil, natural gas and electricity to produce, all of which require large quantities of water. Producing 96 million balls of standard 5mm thickness would use an estimated 2.9 million cubic metres of water. During their time on the reservoir, the balls are estimated to have saved 1.15 million cubic metres of water.

This is alongside other potentially negative effects on the water, such as affecting life in the reservoir or promoting bacterial growth. In addition, the balls’ production could have negative effects on the environment associated with water pollution or carbon emissions.<<

https://www.sciencedaily.com/releases/2018/07/180716114605.htm

>>Federal rules mandate that all bodies of drinking water open to the air be covered. Floating covers provide more of a complete barrier from both sunlight and airborne contaminants, says Harasick. The shade balls will only remain at Los Angeles Reservoir, and that’s because it would be cost-prohibitive — to the tune of $250 million — to install a floating cover on the 175-acre reservoir, which holds a total of 3.3 billion gallons of water, enough water to fill the Rose Bowl five times. At 36 cents a pop, the 96 million plastic balls covering the surface have a lifespan of 10 years and require almost no maintenance aside from occasional rotation. In addition, Harasick adds, “we are experiencing cost savings in the reduced use of chlorine because the shade balls have reduced the amount of algae growth requiring treatment.” The LADWP also estimates they’ll see 300 million gallons in water savings with the shade balls.<<

https://www.governing.com/topics/transportation-infrastructure/gov-shade-balls-water-quality.html

>>Why shade balls aren’t such a great idea after all

In their press release, Garcetti’s office noted that the shade balls will save 300 million gallons of water a year, which otherwise would be lost to evaporation. Sounds like a lot. But how much is 300 million gallons of water worth?

About $2 million at current rates.

The cost of the shade balls? $34.5 million.

To be sure, shade balls will prevent evaporation. But the 300 million gallons a year these plastic balls are supposed to save is really not a whole lot, especially compared to the amount of water used by industry and agriculture. Fracking alone uses 2.14 million gallons of fresh water in California every day, Liboiron writes, and if the agriculture industry cut its water use by only 5 percent, that would save 500 billion gallons in a matter of months.<<

https://grist.org/article/why-shade-balls-arent-such-a-great-idea-after-all/

mollwollfumble said:

On recent trip, I couldn’t help noticing that farmers and government are still doing SFA to reduce evaporation from dams and ponds.

Working through the engineering, I quickly came to to the conclusion that man-made windbreaks are the way to go.

Consider the alternatives:

• Floating surface layer – chemicals
  This is either poisonous or edible. Neither is good for stock or wildlife.

There was an article just recently on ABC about a new non toxic Australian product.

roughbarked said:

mollwollfumble said:

On recent trip, I couldn’t help noticing that farmers and government are still doing SFA to reduce evaporation from dams and ponds.

Working through the engineering, I quickly came to to the conclusion that man-made windbreaks are the way to go.

Consider the alternatives:

• Floating surface layer – chemicals
  This is either poisonous or edible. Neither is good for stock or wildlife.

There was an article just recently on ABC about a new non toxic Australian product.

Can’t find it yet.
but this site hecks out a few methods and costs them.

https://ramblingsdc.net/Australia/EvapReduc.html

and from Israel; The balls are a good idea — in principle. But according to Israeli water tech start-up NeoTop Water Systems, its water-ball solution is better on all counts than the one implemented in California. “Not only is our solution cheaper, but it also saves more water. Using our method, we are able to decrease evaporation by 90%,” said Zeev Birger, the company’s founder. “If we manage to cover all of Israel’s reservoirs, we might be able to double our water supply in Israel.”

ethylene glycol monooctadecyl ether.
Wiki: During a prolonged drought in Australia at the start of this century, scientists there from a number of research institutions, including Pr. David Solomon, inventor of the polymer banknote, set about developing a product that is efficacious, resistant to the deleterious effects of wind, and affordable. In addition to small and large scale field trials, new techniques were utilised including a novel evaporation tank with a controlled climate system to mimic the effects of wind and waves, and computational modelling was for the first time employed to relate dynamic and geometric properties at the atomistic level, with evaporation suppressing performance at the macroscopic level. The use of ethylene glycol monooctadecyl ether was found to substantially decrease evaporation resistance in the presence of wind, and the addition of a water-soluble polymer further enhanced its effectiveness.

Toxicity? https://www.who.int/ipcs/publications/cicad/en/cicad45.pdf
Ebvironmental? https://www.who.int/ipcs/publications/cicad/en/cicad22.pdf

Anyhow, an inground tank will likely not evaporate at all.

roughbarked said:

roughbarked said:

mollwollfumble said:

On recent trip, I couldn’t help noticing that farmers and government are still doing SFA to reduce evaporation from dams and ponds.

Working through the engineering, I quickly came to to the conclusion that man-made windbreaks are the way to go.

Consider the alternatives:

• Floating surface layer – chemicals
  This is either poisonous or edible. Neither is good for stock or wildlife.

There was an article just recently on ABC about a new non toxic Australian product.

Can’t find it yet.
but this site hecks out a few methods and costs them.

https://ramblingsdc.net/Australia/EvapReduc.html

and from Israel; The balls are a good idea — in principle. But according to Israeli water tech start-up NeoTop Water Systems, its water-ball solution is better on all counts than the one implemented in California. “Not only is our solution cheaper, but it also saves more water. Using our method, we are able to decrease evaporation by 90%,” said Zeev Birger, the company’s founder. “If we manage to cover all of Israel’s reservoirs, we might be able to double our water supply in Israel.”

If the floating ball idea actually works it seems extraordinary that it hasn’t been implemented much up till now, since it has been around for ages.

Maybe water is just too cheap.

The Rev Dodgson said:

roughbarked said:

roughbarked said:

There was an article just recently on ABC about a new non toxic Australian product.

Can’t find it yet.
but this site hecks out a few methods and costs them.

https://ramblingsdc.net/Australia/EvapReduc.html

and from Israel; The balls are a good idea — in principle. But according to Israeli water tech start-up NeoTop Water Systems, its water-ball solution is better on all counts than the one implemented in California. “Not only is our solution cheaper, but it also saves more water. Using our method, we are able to decrease evaporation by 90%,” said Zeev Birger, the company’s founder. “If we manage to cover all of Israel’s reservoirs, we might be able to double our water supply in Israel.”

If the floating ball idea actually works it seems extraordinary that it hasn’t been implemented much up till now, since it has been around for ages.

Maybe water is just too cheap.

It is more that everything else is too expensive.

I dunno, how much is water really worth?
People should try living in a desert for a bit. There’s only so much water in a bottle.

roughbarked said:

The Rev Dodgson said:

roughbarked said:

Can’t find it yet.
but this site hecks out a few methods and costs them.

https://ramblingsdc.net/Australia/EvapReduc.html

and from Israel; The balls are a good idea — in principle. But according to Israeli water tech start-up NeoTop Water Systems, its water-ball solution is better on all counts than the one implemented in California. “Not only is our solution cheaper, but it also saves more water. Using our method, we are able to decrease evaporation by 90%,” said Zeev Birger, the company’s founder. “If we manage to cover all of Israel’s reservoirs, we might be able to double our water supply in Israel.”

If the floating ball idea actually works it seems extraordinary that it hasn’t been implemented much up till now, since it has been around for ages.

Maybe water is just too cheap.

It is more that everything else is too expensive.

I dunno, how much is water really worth?
People should try living in a desert for a bit. There’s only so much water in a bottle.

Living on rain filled tank water makes people very water conscious.

Tamb said:

roughbarked said:

The Rev Dodgson said:

If the floating ball idea actually works it seems extraordinary that it hasn’t been implemented much up till now, since it has been around for ages.

Maybe water is just too cheap.

It is more that everything else is too expensive.

I dunno, how much is water really worth?
People should try living in a desert for a bit. There’s only so much water in a bottle.

Living on rain filled tank water makes people very water conscious.

Indeed so.

keeps the water cool does evaporation, good that way

happening everywhere, have a hunch this water phase transition business probably made life possible, the abundance anyway

I like water, been thirsty a few times, there’s a horror in the background of strong thirst desire, so strong I suspect some of the species died of dehydration

So you wouldn’t go with a wooden, aluminium, steel or plastic fence to keep the wind off?

Why not?