Write a letter to the editor of The India Times raising concern over the decreasing ground water level in your locality.
Answers
Groundwater is a valuable resource both in the United States and throughout the world. Where surface water, such as lakes and rivers, are scarce or inaccessible, groundwater supplies many of the hydrologic needs of people everywhere. In the United States, it is the source of drinking water for about half the total population and nearly all of the rural population, and it provides over 50 billion gallons per day for agricultural needs. Groundwater depletion, a term often defined as long-term water-level declines caused by sustained groundwater pumping, is a key issue associated with groundwater use. Many areas of the United States are experiencing groundwater depletion.
Excessive pumping can overdraw the groundwater "bank account"
The water stored in the ground can be compared to money kept in a bank account. If you withdraw money at a faster rate than you deposit new money you will eventually start having account-supply problems. Pumping water out of the ground faster than it is replenished over the long-term causes similar problems. The volume of groundwater in storage is decreasing in many areas of the United States in response to pumping. Groundwater depletion is primarily caused by sustained groundwater pumping. Some of the negative effects of groundwater depletion:
drying up of wells
reduction of water in streams and lakes
deterioration of water quality
increased pumping costs
land subsidence
What are some effects of groundwater depletion?
Pumping groundwater at a faster rate than it can be recharged can have some negative effects of the environment and the people who make use of the water:
LOWERING OF THE WATER TABLE
Chart showing lowering groundwater levels at a well in Oregon.
Pumping has removed water from storage in basalt aquifers and caused declines in many areas of the Columbia Plateau.
The most severe consequence of excessive groundwater pumping is that the water table, below which the ground is saturated with water, can be lowered. For water to be withdrawn from the ground, water must be pumped from a well that reaches below the water table. If groundwater levels decline too far, then the well owner might have to deepen the well, drill a new well, or, at least, attempt to lower the pump. Also, as water levels decline, the rate of water the well can yield may decline.
REDUCTION OF WATER IN STREAMS AND LAKES
There is more of an interaction between the water in lakes and rivers and groundwater than most people think. Some, and often a great deal, of the water flowing in rivers comes from seepage of groundwater into the streambed. Groundwater contributes to streams in most physiographic and climatic settings. The proportion of stream water that comes from groundwater inflow varies according to a region's geography, geology, and climate.
Groundwater pumping can alter how water moves between an aquifer and a stream, lake, or wetland by either intercepting groundwater flow that discharges into the surface-water body under natural conditions, or by increasing the rate of water movement from the surface-water body into an aquifer. A related effect of groundwater pumping is the lowering of groundwater levels below the depth that streamside or wetland vegetation needs to survive. The overall effect is a loss of riparian vegetation and wildlife habitat.
LAND SUBSIDENCE
Answer:
Ground-water use has many societal benefits. It is the source of drinking water for about half the nation and nearly all of the rural population, and it provides over 50 billion gallons per day in support of the Nation’s agricultural economy. Ground-water depletion, a term often defined as long-term water-level declines caused by sustained ground-water pumping, is a key issue associated with ground-water use. Many areas of the United States are experiencing ground-water depletion.
Explanation:
An aquifer can be compared to a bank account, and ground water occurring in an aquifer is analogous to the money in the account. Hydrologists refer to this type of accounting as a water budget. Ground water can be recharged (deposited) by infiltration from precipitation, surface water, or applied irrigation water; it can be kept in storage (saved); and it can be discharged naturally to streams, springs, or seeps, or transpired by plants (withdrawn). In a ground-water system prior to development, the system is in longterm equilibrium—discharge is equal to recharge, and the volume of water in storage remains relatively constant. Ground-water levels fluctuate in time over a relatively small, natural range. Once pumping begins, however, this equilibrium is changed and ground-water levels decline. Just as a bank account must be balanced, withdrawals from an aquifer by pumping must be balanced by some combination of increased recharge, decreased discharge, and removal from storage (or depletion). An inventory of ground-water levels in wells reflects the volume of water stored (or occurring) in the aquifer, and is analogous to a financial statement.
- An aquifer can be compared to a bank account, and ground water occurring in an aquifer is analogous to the money in the account.
The volume of ground water in storage is decreasing in many areas of the United States in response to pumping. Ground-water depletion is primarily caused by sustained ground-water pumping. Some of the negative effects of ground-water depletion include increased pumping costs, deterioration of water quality, reduction of water in streams and lakes, or land subsidence. Such effects, while variable, happen to some degree with any ground-water use. As with other natural resources, society must weigh the benefits against the consequences of such use. In order to provide the scientific information needed for informed decisions, these effects must be observed over time to determine their impact.