Negative aspects of dams:
Dams are extremely expensive to build and must be built to a very high standard.
The high cost of dam construction means that they must operate for many decades to become profitable. [
The flooding of large areas of land means that the natural environment is destroyed.
People living in villages and towns that are in the valley to be flooded, must move out. This means that they lose their farms and businesses. In some countries, people are forcibly removed so that hydro-power schemes can go ahead.
The building of large dams can cause serious geological damage. For example, the building of the Hoover Dam in the USA triggered a number of earth quakes and has depressed the earth's surface at its location.
Although modern planning and design of dams is good, in the past old dams have been known to be breached (the dam gives under the weight of water in the lake). This has led to deaths and flooding.
Dams built blocking the progress of a river in one country usually means that the water supply from the same river in the following country is out of their control. This can lead to serious problems between neighbouring countries.
Building a large dam alters the natural water table level. For example, the building of the Aswan Dam in Egypt has altered the level of the water table. This is slowly leading to damage of many of its ancient monuments as salts and destructive minerals are deposited in the stone work from 'rising damp' caused by the changing water table level.
] Auto answered|Score .8713|Bvijay|Points 60|User:
What are the positive aspects of dams? Weegy:
They can assist in controlling flooding on many rivers.
Dams can by used to create hydro-electric power.
The lakes created are often great recreation areas.
Auto answered|Score .6|badgerpoe|Points 2275|User:
What are some alternatives to dams?
So Many Dam Alternatives
Dams are hardly the only way to meet demand for water, whether it?s new demand due to population growth or to adjust to altered precipitation or runoff patterns resulting from climate change. [
The first step in fighting a new dam is to insist that a reasonable assessment of demand for water is made available. Without knowledge of how much water is needed, discussion of tools to meet demand is premature. Any credible demand assessment should assume future implementation of significant conservation and efficiency measures (click here for more on how to define demand).
Once demand is nailed down, citizens should call for a thorough assessment of supply options to meet that demand.
Water efficiency = Water Supply
Water efficiency and conservation are the simple, proven, cost-effective, and immediate ways to secure new supply and should always be the first options examined. In the Southeast, on average water efficiency costs $0.46 - $250 per 1000 gallons saved while dams cost $4,000 per 1000 gallons. Communities can also avoid or defer significant infrastructure costs through investing a fraction of the money in water efficiency measures as Seattle did when, in the late 1980s it started investing in water efficiency as water supply and avoided $100 million in long-term water supply costs by investing $30 million in water efficiency. (click here for more on water efficiency).
Other supply options may also include:
Reuse: Also known as water recycling or reclamation, water reuse refers to the use of treated sewage, graywater, or stormwater for non-potable purposes such as irrigation, industrial processes, fire protection, toilet flushing, among others. Drawbacks of this option can include costs associated with a municipal scale dual distribution system, and water that would have otherwise returned to the source river/water body once treated is now designated for a consumptive use, in the case of irrigation, that will not return to the river and may result in decreased flows.
Groundwater recharge: This involves recharging underground water sources during a wet year or a season (often winter) when water is available. ] Auto answered|Score 1|asero1010|Points 1166|
All Categories|No Subcategories|Auto answered|8/15/2011 5:32:58 PM