Groundwater in aquifers between layers of poorly permeable rock, such as clay or shale, may be confined under pressure.
What determines if a well will go dry?
A well is said to have gone dry when water levels drop below a pump intake. This does not mean that a dry well will never have water in it again, as the water level may come back through time as recharge increases. The water level in a well depends on a number of things, such as the depth of the well, the type (confined or unconfined) of aquifer the well taps, the amount of pumping that occurs in this aquifer, and the amount of recharge occurring. Wells screened in unconfined water table aquifers are more directly influenced by the lack of rain than those screened in deeper confined aquifers. A deep well in a confined aquifer in an area with minimal pumping is less likely to go dry than a shallow, water table well.
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Related Content
How important is groundwater?
Groundwater, which is in aquifers below the surface of the Earth, is one of the Nation's most important natural resources. Groundwater is the source of about 37 percent of the water that county and city water departments supply to households and businesses (public supply). It provides drinking water for more than 90 percent of the rural population who do not get their water delivered to them from...
What is groundwater?
Groundwater is water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table. Contrary to popular belief, groundwater does not form underground rivers. It fills the pores and fractures in underground materials such as sand, gravel, and other rock, much the same way that water fills a sponge. If groundwater flows...
How can I find the depth to the water table in a specific location?
The depth to the water table can change (rise or fall) depending on the time of year. During the late winter and spring when accumulated snow starts to melt and spring rainfall is plentiful, water on the surface infiltrates into the ground and the water table rises. When water-loving plants start to grow again in the spring and precipitation gives way to hot, dry summers, the water table falls...
What is the Ground Water Atlas of the United States?
This Ground Water Atlas of the United States is a series of USGS publications that describe the location, the extent, and the geologic and hydrologic characteristics of the important aquifers of the Nation. The series consists of 13 chapters that describe the regional groundwater resources that collectively cover 50 States, Puerto Rico, and the U.S. Virgin Islands. Learn more: Principal Aquifers...
Flowing artesian well in Brunswick, Georgia, USA
Groundwater in aquifers between layers of poorly permeable rock, such as clay or shale, may be confined under pressure.
Flowing groundwater site in Indiana
Flowing groundwater site in Indiana
Flowing groundwater site in Indiana
Flowing well used for stock water, Green River Basin
Flowing well used for stock water, Green River Basin
Flowing well used for stock water, Green River Basin
PubTalk 9/2011 — Tracking the Nation's Groundwater Reserves
--issues facing current and future water supplies
by William Alley, USGS Office of Groundwater
--issues facing current and future water supplies
by William Alley, USGS Office of Groundwater
Well, Well, Well! How Deep is the Water Table?
This month we highlight a new interactive map that allows users to determine the depth to groundwater at any location in the Portland Metropolitan Area, Oregon. This month's episode features an interview with the groundwater project's lead author, USGS hydrologist Daniel Snyder.
This month we highlight a new interactive map that allows users to determine the depth to groundwater at any location in the Portland Metropolitan Area, Oregon. This month's episode features an interview with the groundwater project's lead author, USGS hydrologist Daniel Snyder.
Water Well
Irrigation well in northeastern Arkansas (U.S. Geological Survey photograph by Terrance W. Holland, 2009).
Irrigation well in northeastern Arkansas (U.S. Geological Survey photograph by Terrance W. Holland, 2009).
Related Content
How important is groundwater?
Groundwater, which is in aquifers below the surface of the Earth, is one of the Nation's most important natural resources. Groundwater is the source of about 37 percent of the water that county and city water departments supply to households and businesses (public supply). It provides drinking water for more than 90 percent of the rural population who do not get their water delivered to them from...
What is groundwater?
Groundwater is water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table. Contrary to popular belief, groundwater does not form underground rivers. It fills the pores and fractures in underground materials such as sand, gravel, and other rock, much the same way that water fills a sponge. If groundwater flows...
How can I find the depth to the water table in a specific location?
The depth to the water table can change (rise or fall) depending on the time of year. During the late winter and spring when accumulated snow starts to melt and spring rainfall is plentiful, water on the surface infiltrates into the ground and the water table rises. When water-loving plants start to grow again in the spring and precipitation gives way to hot, dry summers, the water table falls...
What is the Ground Water Atlas of the United States?
This Ground Water Atlas of the United States is a series of USGS publications that describe the location, the extent, and the geologic and hydrologic characteristics of the important aquifers of the Nation. The series consists of 13 chapters that describe the regional groundwater resources that collectively cover 50 States, Puerto Rico, and the U.S. Virgin Islands. Learn more: Principal Aquifers...
Flowing groundwater site in Indiana
Flowing groundwater site in Indiana
Flowing groundwater site in Indiana
Flowing well used for stock water, Green River Basin
Flowing well used for stock water, Green River Basin
Flowing well used for stock water, Green River Basin
PubTalk 9/2011 — Tracking the Nation's Groundwater Reserves
--issues facing current and future water supplies
by William Alley, USGS Office of Groundwater
--issues facing current and future water supplies
by William Alley, USGS Office of Groundwater
Well, Well, Well! How Deep is the Water Table?
This month we highlight a new interactive map that allows users to determine the depth to groundwater at any location in the Portland Metropolitan Area, Oregon. This month's episode features an interview with the groundwater project's lead author, USGS hydrologist Daniel Snyder.
This month we highlight a new interactive map that allows users to determine the depth to groundwater at any location in the Portland Metropolitan Area, Oregon. This month's episode features an interview with the groundwater project's lead author, USGS hydrologist Daniel Snyder.
Water Well
Irrigation well in northeastern Arkansas (U.S. Geological Survey photograph by Terrance W. Holland, 2009).
Irrigation well in northeastern Arkansas (U.S. Geological Survey photograph by Terrance W. Holland, 2009).