How much water is stored in the atmosphere, on the land surface, or below the ground? How much precipitation falls over the ocean or over land each year?
Pools and Fluxes and Data VIZ
This interactive data visualization tool shows the size of global pools and fluxes of water, and includes examples of specific pools and fluxes for context.
Zoomable Water Cycle Diagram
Zoom in on our newest water cycle diagram and explore the different pools and fluxes of the water cycle. The zoomable diagram is available in both English and Spanish.
• Water Science School HOME • The Water Cycle
Pools are places where water is stored, like the ocean. Fluxes are the ways that water moves between pools, such as evaporation, precipitation, discharge, recharge, or human use. The table below provides estimates of the sizes of all major water pools and fluxes on Earth.
The volume of water pools is estimated in cubic kilometers [km3]. Flux rates, or the volume of water that moves between pools every year, are estimated in cubic kilometers per year [km3 yr-1]. For reference, we also provide the estimates in the equivalent number of Olympic swimming pools.
These data come from the scientific literature (Abbott and others, 2019). Abbott et al. note that the estimate for each pool or flux "represents the most recent or comprehensive individual estimate." The ranges for each estimate "represent the range of reported values and their uncertainties."
| Pool | Volume estimate (cubic kilometers [km3]) | Range (cubic kilometers [km3]) | Volume estimate (number of Olympic swimming pools, in millions) | Range (number of Olympic swimming pools, in millions) |
|---|---|---|---|---|
| Ocean (deep water zone) | 1,206,000,000 | 1,100,000,000 to 1,300,000,000 | 482,400,000 | 440,000,000 to 520,000,000 |
| Ocean (mixed zone) | 134,000,000 | 90,000,000 to 170,000,000 | 53,600,000 | 36,000,000 to 68,000,000 |
| Ice sheets and glaciers | 25,800,000 | 24,064,000 to 29,200,000 | 10,320,000 | 9,625,600 to 11,680,000 |
| Groundwater | 22,600,000 | 8,060,000 to 23,400,000 | 9,040,000 | 3,224,000 to 9,360,000 |
| Permafrost | 207,000 | 22,000 to 300,000 | 82,800 | 8,800 to 120,000 |
| Lakes (fresh) | 108,000 | 91,000 to 125,000 | 43,200 | 36,400 to 50,000 |
| Lakes (saline) | 94,700 | 85,400 to 104,000 | 37,880 | 34,160 to 41,600 |
| Soil moisture | 54,100 | 16,500 to 122,000 | 21,640 | 6,600 to 48,800 |
| Wetlands (fresh and brackish) | 14,100 | 11,000 to 17,000 | 5,640 | 4,400 to 6,800 |
| Reservoirs | 10,800 | 7,000 to 15,000 | 4,320 | 2,800 to 6,000 |
| Atmospheric moisture (over ocean) | 10,000 | 8,000 to 12,000 | 4,000 | 3,200 to 4,800 |
| Atmospheric moisture (over land) | 3,000 | 2,700 to 3,300 | 1,200 | 1,080 to 1,320 |
| Snowpack | 2,900 | 2,600 to 3,500 | 1,160 | 1,040 to 1,400 |
| Rivers | 1,900 | 1,250 to 2,120 | 760 | 500 to 848 |
| Biological water | 940 | 600 to 1,120 | 376 | 240 to 448 |
| Flux | Flux rate estimate (cubic kilometers per year [km3 yr-1]) | Range (cubic kilometers per year [km3 yr-1]) | Flux rate estimate (number of Olympic swimming pools per year, in millions) | Range (number of Olympic swimming pools per year, in millions) |
|---|---|---|---|---|
| Ocean circulation | 7,100,000 | 6,100,000 to 9,100,000 | 2,840,000 | 2,440,000 to 3,640,000 |
| Ocean evaporation | 420,500 | 350,000 to 510,000 | 168,200 | 140,000 to 204,000 |
| Precipitation over ocean | 380,500 | 320,000 to 460,000 | 152,200 | 128,000 to 184,000 |
| Precipitation over land | 110,600 | 99,000 to 120,000 | 44,240 | 39,600 to 48,000 |
| Evapotranspiration | 68,900 | 62,000 to 75,000 | 27,560 | 24,800 to 30,000 |
| Transport of moisture from ocean to land | 46,000 | 35,00 to 50,000 | 18,400 | 14,000 to 20,000 |
| Streamflow to ocean | 46,000 | 36,000 to 56,000 | 18,400 | 14,400 to 22,400 |
| Groundwater recharge | 13,000 | 12,000 to 25,000 | 5,200 | 4,800 to 10,000 |
| Grazing water use | 10,000 | 8,200 to 14,000 | 4,000 | 3,280 to 5,600 |
| Agricultural water use | 10,840 | 7,850 to 12,000 | 4,336 | 3,140 to 4,800 |
| Groundwater discharge to ocean | 4,500 | 100 to 6,500 | 1,800 | 40 to 2,600 |
| Industrial water use | 1,130 | 840 to 1,390 | 452 | 336 to 556 |
| Forestry water use | 960 | 800 to 1,200 | 384 | 320 to 480 |
| Streamflow to closed basins | 800 | 600 to 1,100 | 320 | 240 to 440 |
| Municipal and domestic water use | 590 | 380 to 680 | 236 | 152 to 272 |
Sources and more information:
- Abbott, B.W., Bishop, K., Zarnetske, J.P. et al. (2019) Human domination of the global water cycle absent from depictions and perceptions. Nature Geoscience 12, 533-540.
How much water is stored in the atmosphere, on the land surface, or below the ground? How much precipitation falls over the ocean or over land each year?
Pools and Fluxes and Data VIZ
This interactive data visualization tool shows the size of global pools and fluxes of water, and includes examples of specific pools and fluxes for context.
Zoomable Water Cycle Diagram
Zoom in on our newest water cycle diagram and explore the different pools and fluxes of the water cycle. The zoomable diagram is available in both English and Spanish.
• Water Science School HOME • The Water Cycle
Pools are places where water is stored, like the ocean. Fluxes are the ways that water moves between pools, such as evaporation, precipitation, discharge, recharge, or human use. The table below provides estimates of the sizes of all major water pools and fluxes on Earth.
The volume of water pools is estimated in cubic kilometers [km3]. Flux rates, or the volume of water that moves between pools every year, are estimated in cubic kilometers per year [km3 yr-1]. For reference, we also provide the estimates in the equivalent number of Olympic swimming pools.
These data come from the scientific literature (Abbott and others, 2019). Abbott et al. note that the estimate for each pool or flux "represents the most recent or comprehensive individual estimate." The ranges for each estimate "represent the range of reported values and their uncertainties."
| Pool | Volume estimate (cubic kilometers [km3]) | Range (cubic kilometers [km3]) | Volume estimate (number of Olympic swimming pools, in millions) | Range (number of Olympic swimming pools, in millions) |
|---|---|---|---|---|
| Ocean (deep water zone) | 1,206,000,000 | 1,100,000,000 to 1,300,000,000 | 482,400,000 | 440,000,000 to 520,000,000 |
| Ocean (mixed zone) | 134,000,000 | 90,000,000 to 170,000,000 | 53,600,000 | 36,000,000 to 68,000,000 |
| Ice sheets and glaciers | 25,800,000 | 24,064,000 to 29,200,000 | 10,320,000 | 9,625,600 to 11,680,000 |
| Groundwater | 22,600,000 | 8,060,000 to 23,400,000 | 9,040,000 | 3,224,000 to 9,360,000 |
| Permafrost | 207,000 | 22,000 to 300,000 | 82,800 | 8,800 to 120,000 |
| Lakes (fresh) | 108,000 | 91,000 to 125,000 | 43,200 | 36,400 to 50,000 |
| Lakes (saline) | 94,700 | 85,400 to 104,000 | 37,880 | 34,160 to 41,600 |
| Soil moisture | 54,100 | 16,500 to 122,000 | 21,640 | 6,600 to 48,800 |
| Wetlands (fresh and brackish) | 14,100 | 11,000 to 17,000 | 5,640 | 4,400 to 6,800 |
| Reservoirs | 10,800 | 7,000 to 15,000 | 4,320 | 2,800 to 6,000 |
| Atmospheric moisture (over ocean) | 10,000 | 8,000 to 12,000 | 4,000 | 3,200 to 4,800 |
| Atmospheric moisture (over land) | 3,000 | 2,700 to 3,300 | 1,200 | 1,080 to 1,320 |
| Snowpack | 2,900 | 2,600 to 3,500 | 1,160 | 1,040 to 1,400 |
| Rivers | 1,900 | 1,250 to 2,120 | 760 | 500 to 848 |
| Biological water | 940 | 600 to 1,120 | 376 | 240 to 448 |
| Flux | Flux rate estimate (cubic kilometers per year [km3 yr-1]) | Range (cubic kilometers per year [km3 yr-1]) | Flux rate estimate (number of Olympic swimming pools per year, in millions) | Range (number of Olympic swimming pools per year, in millions) |
|---|---|---|---|---|
| Ocean circulation | 7,100,000 | 6,100,000 to 9,100,000 | 2,840,000 | 2,440,000 to 3,640,000 |
| Ocean evaporation | 420,500 | 350,000 to 510,000 | 168,200 | 140,000 to 204,000 |
| Precipitation over ocean | 380,500 | 320,000 to 460,000 | 152,200 | 128,000 to 184,000 |
| Precipitation over land | 110,600 | 99,000 to 120,000 | 44,240 | 39,600 to 48,000 |
| Evapotranspiration | 68,900 | 62,000 to 75,000 | 27,560 | 24,800 to 30,000 |
| Transport of moisture from ocean to land | 46,000 | 35,00 to 50,000 | 18,400 | 14,000 to 20,000 |
| Streamflow to ocean | 46,000 | 36,000 to 56,000 | 18,400 | 14,400 to 22,400 |
| Groundwater recharge | 13,000 | 12,000 to 25,000 | 5,200 | 4,800 to 10,000 |
| Grazing water use | 10,000 | 8,200 to 14,000 | 4,000 | 3,280 to 5,600 |
| Agricultural water use | 10,840 | 7,850 to 12,000 | 4,336 | 3,140 to 4,800 |
| Groundwater discharge to ocean | 4,500 | 100 to 6,500 | 1,800 | 40 to 2,600 |
| Industrial water use | 1,130 | 840 to 1,390 | 452 | 336 to 556 |
| Forestry water use | 960 | 800 to 1,200 | 384 | 320 to 480 |
| Streamflow to closed basins | 800 | 600 to 1,100 | 320 | 240 to 440 |
| Municipal and domestic water use | 590 | 380 to 680 | 236 | 152 to 272 |
Sources and more information:
- Abbott, B.W., Bishop, K., Zarnetske, J.P. et al. (2019) Human domination of the global water cycle absent from depictions and perceptions. Nature Geoscience 12, 533-540.