For many domestic wells, the cones of depression often are too small to even show up on such maps.

In huge municipal wells, these cones of depression often can extend many miles from the pumped well.

A cone of depression occurs in an aquifer when groundwater is pumped from a well.

The size and shape (slope) of the cone of depression depends on many factors.

However, aquifer characteristics can affect the shape of the cone of depression.

Cones of depression can be really useful when dealing with contaminant plumes in ground water.

Over decades, if overpumping continues, salty ocean water might fill the cone of depression, as it has done here.

This conical-shaped feature is the cone of depression.

We typically think of a cone of depression as being a circular feature surrounding the pumped well.

Often, a well can be placed near a contaminant plume and pumped at a sufficient rate to create a cone of depression.

The outer edge of that cone of depression is now beginning to suck water from the San Pedro.

Contour maps often show "bulls-eyes" around pumped wells that represent the cones of depression.

This cone of depression can act to capture the contaminant flow (essentially pulling it out of the aquifer).

The pumping has created what hydrologists call a "cone of depression" in the aquifer, which is much like the vortex in a drain.

In confined aquifers (artesian), the cone of depression is a reduction in the pressure head surrounding the pumped well.

Even in the water-rich Great Lakes region, over-pumping can locally lower water levels in "cones of depression".

"When you pump a well it creates a cone of depression, like when you pull the plug out of your bathtub.

The shape of the cone of depression also can be affected when the cone intersects a source of water, such as a lake or stream.

Mr. Behrens said pumping from Atlantic City had caused a cone of depression that sunk the ground and expanded outward a foot per year.

The amount of water in storage and the thickness of the aquifer also will determine the size and shape of the cone of depression.

As a well is pumped, the cone of depression will extend out and will continue to expand in a radial fashion until a point of equilibrium occurs.

In such cases, water from the lake or stream supplies water to the cone of depression and therefore the cone will not expand as far in this direction.

In the case of water supply wells, whether for domestic use or irrigation, wells typically are placed far enough apart in order to avoid intersecting cones of depression.

Much of the aquifer in that stretch has been heavily pumped and contains a precursor of a salt front invasion: a huge V-shaped void that hydrologists call a cone of depression.

When two cones of depression intersect one another, they tend to have a combined effect on drawdown and result in water levels or pressures much lower than a single cone of depression would produce.