Why is Groundwater Important?
• Drinking water for nearly 50% of US
• 98% of rural domestic supplies
• 35% of public supplies• 42% of irrigation for
agriculture• Sustains flow of
streams and rivers• Maintains aquatic
ecosystems
Contribution to Streamflow
54 StreamsRange 14-90%Average 52%
• Geology• Physiography• Climate
Runoff
Runoff
GW
GW
GW
Why Measure Water Levels?“You can’t manage what you don’t
measure”
• Water level in a well is an indirect measure of the amount of water in the aquifer.
• Principal source of information on the hydrologic stress on the aquifer
• Provides the data necessary to – evaluate changes in the resource over time – develop models and forecast trends, and – design, implement, and monitor the
effectiveness of groundwater management programs
GWRP Regional GW Availability
• Quantify current groundwater resources
• Evaluate how these resources have changed over time
• Provide tools to forecast system responses to stresses from future human and environmental uses.
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