KenneyAPESCh13

1. When an aquifer is refilled via lakes, rivers, and streams
3. Prolonged period in which precipitation is at least 70% lower than average
4. Locations in which water could create political and legal conflicts because of needs for cities, irrigation, wildlife, and recreation
6. Structure built across a river to control the river's flow
7. When an aquifer is refilled via precipitation
11. Have very little water and were formed thousands of years ago
13. When the land above and aquifer sinks and turns into a sinkhole
16. Top of groundwater zone
18. To sink
19. Created when groundwater from aquifers flows out of the ground
21. Usable surface runoff

2. Movement of water in the seas, air, and land
5. Any lake, river, wetland, or other body of water that water is drained into (one word)
8. Aquifer that will be used in the future to support the growing population
9. Any lake, river, wetland, or other body of water that water is drained into (two words)
10. Underground spaces completely filled with water
12. Precipitation that does not infiltrate the ground or return to the atmosphere by evaporation
14. Freshwater from precipitation and melted snow that flows across the earth's land surface
15. Water resting on bedrock. One of the most important sources of freshwater
17. Underground caverns and porous layers of sand, gravel, or rock which water flows through
20. Artificial lake behind a dam