Why Are 96,000,000 Black Balls on This Reservoir?

I took a boat through 96 million black plastic balls on the Los Angeles reservoir to find out why they're there. The first time I heard about shade balls the claim was they reduce evaporation. But it turns out this isn't the reason they were introduced.
Huge thanks to LADWP for arranging this special tour for me. Next time let's put the GoPro on the submersible!
The balls are made of high density polyethylene (HDPE) which is less dense than water so they float on the surface of the reservoir even if they break apart. They are 10cm (4 inches) in diameter and contain about 210ml of water. So the main reason they are on the reservoir is to block sunlight from entering the water and triggering a chemical reaction that turns harmless bromide into carcinogenic bromate. This effect occurs with prolonged exposure to bromate so regulators insist that levels be kept below 10 microgram per liter on average over a 12 month period.
Special thanks to Patreon supporters:
Donal Botkin, Michael Krugman, Ron Neal, Stan Presolski, Terrance Shepherd, Penward Rhyme and everyone who provided feedback on an early draft of this video.
Thanks to:
Las Virgenes Reservoir for footage of initial shade ball dump
Euro-Matic for bird into jet-engine footage
Researched and Produced by Casey Rentz
Animations by Maria Raykova
Music from epidemicsound.com "Colorful Animation 4" "Seaweed"
And from Kevin MacLeod "Marty Gots a Plan"
This is an educational video about the science of water quality.


  1. B V

    B V9 hours ago

    Is really rare to see 96 millions of anything Ilegal imigrants jumping the wall at the border. :: am I a joke to you? 🧗‍♂️

  2. B V

    B V9 hours ago

    So u had your balls in the water i drink

  3. ray boyce

    ray boyce13 hours ago


  4. Josh Symonds

    Josh Symonds14 hours ago

    Imagine putting a dollar in each one of the balls. A billionaire has enough for TEN of these reservoirs, and they would still have $40 million dollars leftover!

  5. P/\TRIOT

    P/\TRIOT15 hours ago

    I got this suggestion after watching a few videos of sand bubbler crabs. I think USwork is starting to think that I like balls. #zefrank

  6. TheCaliRhino

    TheCaliRhino15 hours ago

    So we’re just gonna gloss over the fact that they use chlorine to disinfect the water? Uh, why not carbon/charcoal filters? Oh yeah, CaliFuckYa just wants to spend more tax dollars! I almost forgot 🖕🤓🖕

  7. Oracio Rodriguez

    Oracio Rodriguez15 hours ago


  8. lucas Delacruz

    lucas Delacruz17 hours ago

    Why are they black ?? 😑

  9. h h

    h h17 hours ago

    I always see this.

  10. Miguel McCoy

    Miguel McCoy17 hours ago

    They just killed a bird 😭 5:51

  11. Paul Hagelston

    Paul Hagelston20 hours ago

    ...96,000,000 Black Balls

  12. Daniel Stewart

    Daniel StewartDay ago

    You would think the prop would tear up the shade balls. I am surprised they don’t use a flat bottom fan boat (swamp boat). Then again maybe the fan would blow the shade balls away and the prop works below the shade balls? Pondering 🤔

  13. truemues YT

    truemues YTDay ago

    Anyone saw the bird that got killed bec of the fan thingies 5:51

  14. Lincoln Haubner

    Lincoln HaubnerDay ago

    “Why are they black?” Because would you rather see 96million blue balls?

  15. simply_ kim

    simply_ kimDay ago


  16. cal turner

    cal turnerDay ago

    Always bet on Black

  17. John-Michael Carlin

    John-Michael CarlinDay ago

    I wonder if these would cut down algea in other water bodies..

  18. Raphaël D

    Raphaël DDay ago

    What if someone thinks there is actual ground under those balls and tries to walk on them?

  19. CrashArenaTurboFan

    CrashArenaTurboFanDay ago

    I thought it was black because it will keep the water warm since dark colors mean more heat trapped in so then the trapped heat would keep the water warm.

  20. laws stack

    laws stackDay ago

    Vsco girls are having vsco seizures

  21. Phil Capone

    Phil CaponeDay ago

    The real reason: mayor's son manufactures little black balls, so why not buy 96 million with taxpayer money

  22. rocksunjaxindie

    rocksunjaxindieDay ago

    Could this possibly be any more fuckin boring?

  23. Isaac Smith

    Isaac SmithDay ago

    1:24 this guy loves to talk about shade balls.

  24. Joe Schmo

    Joe SchmoDay ago

    Hehehehe balls

  25. Eli You don’t need to know

    Eli You don’t need to knowDay ago

    I only counted 95,999,999

  26. Landon Tanger

    Landon TangerDay ago

    Dude they are putting a gas motor in a place where people drink from

  27. Sadiq’s IQ

    Sadiq’s IQDay ago

    0:37 germs

  28. Kart Man

    Kart ManDay ago

    *Best thing about the shade balls is it made all the birds leave. That’s awesome.*

  29. Andrew Ray

    Andrew RayDay ago

    why cant the water be treated after it leaves the reservoir? do you not like wildlife that sustains life on earth, including the human race.

  30. True Janey  Sue

    True Janey SueDay ago

    Learning something new every day!👍

  31. Joseph Bennett

    Joseph BennettDay ago

    Haha three black balls for a dollar.

  32. Joseph Bennett

    Joseph BennettDay ago

    Haha just think if a tornado would ever form there and suck all of those up , people would be have black balls speed like bullets through the air and go through everything in its path.



    Such a Waste of Money. Have some shame

  34. Eddie Guerrero

    Eddie GuerreroDay ago

    Those are my black Balls

  35. Joe Duke

    Joe DukeDay ago

    Black mothers have murdered 37 million of their children, so there are only 74,000,000 black balls here.

  36. Corry Miklos

    Corry MiklosDay ago

    Rip that bird

  37. s k

    s k2 days ago

    Ask the 48 million black men who were neutered.

  38. Jibran Ahmed

    Jibran Ahmed2 days ago

    I hate when all my black balls fall into water, ike tbis is the last time it will happen

  39. Napi Coyote

    Napi Coyote2 days ago

    Black balls are important too... 🧐

  40. Elmo The Wise

    Elmo The Wise2 days ago

    Giant Big Black Balls...

  41. FranksDD15

    FranksDD152 days ago

    Did that girl say that birds were loitering on the curb? Lol

  42. Princess Rodriguez

    Princess Rodriguez2 days ago

    “ why are they *black* ”

  43. MR.B1z3

    MR.B1z32 days ago

    5:51 anyone ealse see that a bird went in the engine?

  44. The Vinity Vines

    The Vinity Vines2 days ago

    Can I swim there

  45. The Vinity Vines

    The Vinity Vines2 days ago

    Pewdiepie has more sub than this Lol

  46. John Pedder

    John Pedder2 days ago

    Did anyone get the answer? I stopped watching after 2 minutes of redundant comments.

  47. Rara Ratna

    Rara Ratna2 days ago

    I watch this video waiting someone jump onto Lake with billion black balls.. but nobody..😕😕😕

  48. Techniq

    Techniq2 days ago

    Ok youtube I've done it can you pls stop now?

  49. Derek O'Brien

    Derek O'Brien2 days ago

    How is the bromide getting into yje eater? Are there natyrak sources in the supply chain?

  50. GalaxyGuy14

    GalaxyGuy142 days ago

    So what Pokémon does it do well to catch?

  51. Greystorm1619

    Greystorm16192 days ago

    That’s actually really cool though, this video was so fascinating I actually watched it all the way through

  52. A Christian Report

    A Christian Report2 days ago

    Some smart people to come up with that. Just not cool with the boat in my drinking water🤔

  53. reginald chapman

    reginald chapman15 hours ago

    The boat ain't the problem, it's all those plastic balls bleeding estrogen like chemicals into your water. The people who came up with this either are so ignorant they shouldn't be in positions of power or they aren't ignorant then they should be in jail for introducing that much plastic into the water supply.

  54. bbfreetube

    bbfreetube2 days ago

    As an environmentalist, I cannot condone this.

  55. L Johnson

    L Johnson9 hours ago

    OK, now see where that gets you.

  56. Kuality

    Kuality2 days ago

    pewdiepie has more subs than the amount of balls in that entire reservoir

  57. James Baron

    James Baron2 days ago

    Man this video really blew up. Like my comment

  58. Shazam Shazam7384

    Shazam Shazam73842 days ago

    in the video 5:50 u Should see a Bird

  59. Shazam Shazam7384

    Shazam Shazam73842 days ago

    Did nobody saw how Did the Bird Die in the video

  60. XX ZEUS XX

    XX ZEUS XX2 days ago

    5:52 anyone saw the bird going in the plane


    SALAM JIHAD2 days ago


  62. BITTER_ MEDicine

    BITTER_ MEDicine2 days ago

    Y don't you just fill the whole ocean with black balls then.