Alternative for dams and Water Supply Expansion-PART-I.

Byline: Nusrat Bibi

Of all our available resources, water is the most precious. Public water supply, aquatic habitats, energy generation, agriculture, industrial, commercial uses and recreation -all depend on water. The hydrologic cycle or the water cycle in nature describes the continuous movement of water on, above and below the surface of earth from one reservoir to another such as from rivers to oceans or from oceans to atmosphere and then atmospheric circulation moves water by rain, snow etc through the process of infiltration and surface runoff in rivers and streams and in ground. Most of the earth's water is in ocean and most of the fresh water is stored as ice or below ground in aquifers, thus comparatively little fresh water is available for human use on a global scale, e.g., only 0.77 % of all earth's water is available as fresh ground water or surface water and only .008 percent is available in lakes, rivers and wet lands (Shiklomanove 1993).Thus water conservation is desirable in any water use sector by considering the limited availability of fresh water on a global scale. The rivers health and the availability of fresh water are very much interconnected.

The Nation's network of rivers, lakes and streams originates from a range of small invisible streams and wetlands, yet these head water affect the health and efficiency of downstream water. The natural processes that occur in such head water benefit human by flood mitigation, maintaining quality and quantity of water, recycling nutrients and providing habitats to plants and animals. Therefore the health and productivity of rivers and lakes depend upon the intact streams and wetlands and changes in its vicinity, no matter in land use pattern or in vegetation cover can impair its natural functions and can scour its channels and such altered channels cause more frequent and bigger flood. These channels are also less effective in groundwater recharge, trapping sediments and recycling nutrients. As a result the downstream rivers and lakes water quality, flow and diverse aquatic life is compromised and costly dredging is needed to clean the channels and thus increase water filtration cost for municipalities and community .Therefore to sustain the health of our nation's water, the hydrological, biological and geological characteristics of these wetlands and streams require protection on priority basis.

Healthy rivers and streams support a complete ecosystem, diversity of fish...