water

3. resource derived from dams
4. source of pollution from runoff
5. intrusion overdrawing of coastal aquifers result in ___
7. underground reservoir of water that can be confined or unconfined
9. oxygen needed for microorganisms to decompose water
10. drainage basin
16. this drops when the biochemical oxygen demand is high
18. element along with potassium and phosphorous that stimulate growth of plants and algae
19. relatively clean waste water from sinks, washing machines, etc

1. area adjacent to a river that experiences frequent flooding
2. a result of extended irrigation of soil
6. the uppermost level of groundwater
7. the largest drainage basin in the world
8. the climate of deserts and other areas that experience very little precipitation
11. sinking of land as a result of overdrawing of aquifers
12. nutrient-rich bodies of water whether natural or artificial
13. world's largest aquifer
14. built adjacent to dams to allow salmon and other species to swim upstream
15. largest user of water
17. bodies of water with few nutrients