How seawater is collected
Every kilogram of seawater holds about 35 grams of dissolved salt, and industry pulls it out in two ways.
- stations
- 3
- things downstream
- 49
The short version
Seawater is drawn through intake pipes or shallow channels, screened to remove debris, and then put to work. Salt makers let it evaporate in shallow sunlit ponds, leaving salt behind. Desalination plants instead strip the salt out to make fresh water, using heat or membranes.
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Draw it from the sea
Pumps lift seawater through intake pipes, or tidal channels let it flow into holding ponds. The water carries about 3.5% dissolved salts, mostly sodium and chloride.
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Screen out the debris
Screens and filters take out seaweed, shells and sediment before the water reaches the plant or the ponds.
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Spread it in shallow pans
In a salt evaporation pond, seawater or another brine is fed into shallow artificial pans. Sunlight reaches the water, evaporation takes the water away, and the salt is later harvested.
Worth repeating
- A kilogram of seawater holds about 35 grams of dissolved salts, mostly sodium and chloride.
- Global desalination capacity in 2020 was roughly 97 million cubic meters a day from over 16,800 plants.
- In evaporation ponds, algae and microorganisms turn the water colors from pale green to bright red as the salinity rises.
Where it goes next
Seawater feeds 2 lines directly and reaches 49 things in total.
Further down the line
Keep walking
Sources
Cite this page: "How seawater is collected." Assembly Line, 2026-11-03. https://assemblyline.org/make/seawater