A new initiative by theLos Angeles Department of Water and Power (LADWP) has taken asurprisingly low-tech approach to water conservation, by covering theLA Reservoir in 96 million black "shade balls." It's anattempt to combat water loss through evaporation, and to heighten waterquality.
California's watershortages are now believed to be so severe that the state would nowrequire 20 inches (51 cm) of rainfall – that's the equivalent of an entireyear's precipitation – to remedy the crippling rain debt.
In this context, the LAreservoir has become an even more vital resource, spanning animpressive 175 acres (71 hectares), and holding roughly 3.3 billion US gallons (12.5 billion liters) ofwater – enough to support the entire city of Los Angeles for up tothree weeks.
Each shade balls costs36 cents, with the entire project amounting to US$34.5 million. Whilstthis may sound like a lot of money to turn LA's largest reservoirinto a massive watery ball pit, other water-saving alternatives wouldhave proven far more costly to implement.
Another option that hadbeen under consideration would have seen the reservoir separated intotwo distinct basins with the use of a bisecting dam, and protectedwith a floating cover, at the much greater cost of $300 million.
The unusual strategyrepresents a significant cost savings of around $250 million, andcould prevent the loss of up to 300 million US gallons (1.14 billion liters) of water toevaporation. Simultaneously the shade balls will increasing waterpurity by preventing contamination via wildlife and dust, as well asreducing sunlight-triggered chemical reactions.
It is estimated thatthe sheer quantity of water saved under the initiative will besufficient to provide drinking water to around 8,100 LA residentsfor an entire year. Scroll down for a video showing the release of 20,000 shade balls into the LA Reservoir.
Source: LADWP
Supposedly the black color doesn't hurt because the plastic doesn't conduct heat that much and since they're (mostly) hollow they act as an insulator. (there is a small amount of water in them to keep them from blowing away, evidently.)
how about not releasing 50% of the water to save a baitfish ? maybe only release 45% ... would save enough water for millions of people for a year ...