The criteria for the design of earth dams are: 1. Sufficient spillway capacity and freeboard are provided so that there is no danger of overtopping of the dam 2. Seepage flow through the embankment is controlled so that the amount lost does not interfere with the objective of the dam and there is no erosion(…)
Water Resources
EARTHFILL DAMS & ITS CLASSIFICATION
Earthfill dams are the most common type of dam built to any height. They are designed as a non-overflow section with separate spillway. The reason for such wide spread use of earthfill dams are: The foundation requirements are not as rigorous as other dams Local available soil is the main construction material High skill not(…)
More Efficient Alternate Irrigation Systems
The problem of water shortage continues to grow – both locally and globally. At the same time the need for restoration of dry lands and more food production from deserts and dry lands are both increasing. Buried Clay Pot Irrigation One of the most studied, and very effective systems uses a buried clay pot full(…)
Environmental Impacts of Large Dams
Dams have both intended and unintended impacts, which can be positive or negative. It is unlikely to find intended negative impacts, though positive impacts can be both intended and unintended. Each of these types of impacts can be inevitable in their entirety, reducible or totally avoidable. Most adverse social and environmental impacts of large dams(…)
WATER QUALITY CHECKS IN RAINWATER HARVESTING
If the roof, the gutter, the first rain separator and the filter is kept clean, the collected rainwater will be crystal clear. This is an indication that good maintenance is being followed. If the water is however dirty in color or it smells bad, then it means that the system is not being kept clean.(…)
METHODS OF RAINWATER HARVESTING
Methods of Rainwater Harvesting Broadly there are two ways of harvesting rainwater. (i) Surface runoff harvesting (ii) Roof top rainwater harvesting Various methods of rainwater harvesting are described in this section. 1. Surface runoff harvesting In urban area rainwater flows away as surface runoff. This runoff could be caught and used for recharging aquifers by(…)
FORCES ACTING ON A DAM STRUCTURE
In the design of a dam, the first step is the determination of various forces which acts on the structure and study their nature. Depending upon the situation, the dam is subjected to the following forces: 1. Water pressure 2. Earthquake forces 3. Silt pressure 4. Wave pressure 5. Ice pressure 6. Self weight of(…)
ANALYSIS OF GRAVITY DAM
The stability of a dam can be analysed in the following steps: i. Consider unit length of the dam. ii. Work out the magnitude and dimensions of all the vertical forces acting on the dam and their algebraic sum, i.e. ?V. iii. Similarly work out all the horizontal forces and their algebraic sum i.e. ?H.(…)