Compare Financial alternatives for major purchases - Speech or Presentation Example

What are the positive aspects of dams? The construction of dams has long been acknowledged as one of the most efficient ways to divert water flows inorder to be used for many potentially beneficial uses such as agricultural irrigation, human water consumption, and controlling devastating floods that use to happen in many flood prone areas around the world. Another one of the most significant advantages of artificial dams is the ability to harness the flow of water in order to produce hydroelectric power.

This method is long acknowledged as one of the cleanest of producing electricity of all the currently commercially available technologies (Americanrivers, 2011).The construction of dams also allow for the creation of many opportunities for water sports, the construction of campsites, hiking and biking trails as well as hotels, lodges, and many other businesses around the lakeshore. The increase in tourism in the area along with all the improvements in infrastructure around the area will help develop the local economy and benefit all surrounding communities.

What are the negative aspects of building a dam?The subject of dam construction has been a hotly debated issue especially since the 1960’s when the environmental impact of dam construction started to be considered and analyzed. To start with constructing a new dam is an incredibly expensive and complex undertaking, usually with total project costs running into the billions and taking numerous years to complete (Pottinger, 1996). When a dam is constructed in a river system the whole balance of the ecosystem upstream and downstream of the newly constructed dam will be negatively affected or even completely destroyed as a direct consequence of disrupting the natural seasonal flow of the river system.

Prior to the construction of the dam, the river has a natural flow that responds to the seasonal changes and brings a constant flow of debris and sedimentation that helps bring food and nutrients for all the natural wildlife living in the river system. After a dam is constructed the flow of the water is artificially limited and controlled so the flow is usually constant and very restricted and only increased to decrease water levels or increase power production and does not correlate natural seasonal fluctuations.

Furthermore all the sedimentation and the necessary food and nutrients carried with it will now be deposited in the impoundment upstream of the dam, destroying the ecosystem and killing most of the natural wildlife downstream. The evaporation rate of the river system will be significantly higher because of the vastly greater surface area exposed to the wind and sun of the artificial lake created after dam construction. Another negative factor of eliminating the natural sedimentation will be increased erosion of the water banks and embankments.

The water temperature and average oxygen levels of the river system will be decreased since the water is usually released from a considerable depth in the dam where water temperature and dissolved oxygen levels will be inevitably much lower than normal. This will affect the ability of wildlife to adapt and survive. The magnitude of the environmental effects is correlated directly with the size of the dam itself. The environmental effects are profound and varied and must be carefully considered before a new dam project is authorized.

What are some alternatives to dams?Reusing or recycling non-potable water resources for irrigation, industrial processes and flushing toilets. Water use efficiency and conservation measures should be considered first and foremost in any project considering new dam construction. These types of initiatives can be extremely cost effective ways in controlling the use of water resources and are usually sponsored by local and federal government agencies. Programs designed to conserve water can help save considerable amounts of resources through measures like water-efficient retrofits in residential and commercial establishments which can save upwards of 35% as demonstrated by the results achieved by the city of Boston, Massachusetts in the 1980’s, costing taxpayers $40 million instead of the $500 million required for the small proposed dam (Americanrivers, 2011).

ReferencesAmericanrivers.com (2011). Dam Alternatives. Retrieved November 18, 2011 from http://www.americanrivers.org/our-work/water-supply/water-efficiency/dam-alternatives.html Pottinger, L. (1996). Environmental Impact of Large Dams: African Example. Retrieved November 18, 2011 from http://www.internationalrivers.org/africa/environmental-impacts-large-dams-african-examples