PRESENTATION ON RAIN WATER HARVESTING BY: RAGHAV SINGLA VII-B .ppt (1)

What Is Rainwater Harvesting? RWH consists of simple systems to collect, convey, and store rainwater. Rainwater capture is accomplished primarily from roof-top, surface runoff, and other surfaces. RWH either captures stored rainwater for direct use (irrigation, production, washing, drinking water, etc.) or is recharged into the local ground water and is call artificial recharge. .ppt (2)

Why Rainwater Harvesting? Conserve and supplement existing water resources Supply water at one of the lowest costs possible for a supplemental supply source. Commitment as a corporate citizen - showcasing environmental concerns Replenishing local ground water, where lowering of water tables has occured .ppt (3)

Why Not RWH? Not applicable in all climate conditions over the world Collected water quality might be affected by external factors Performance seriously affected by climate fluctuations that sometimes are hard to predict Collected rainwater can be degraded with the inclusion of waste water runoff .ppt (4)

Let’s take a look at The Water Cycle Condensation Precipitation Evapotranspiration Evaporation Infiltration Narration: The hydrologic or water cycle is the continuous flow of water between reservoirs at or near the earth’s surface. As water falls to the ground as precipitation, it may develop as surface runoff into nearby surface waters or infiltrate into the ground and become stored as groundwater. Water stored in open areas, know as surface water, can evaporate into the atmosphere. In addition, water used by plants for normal growth or transpiration is also returned to the atmosphere. Once in the atmosphere water can condense into clouds and precipitate as rain or snowfall, initiating the cycle over again. Water is a renewable resource that, managed properly, can sustain the activities in the watershed for an indefinite period of time. Animation: shows water cycle Surface Runoff Surface Water Consumption Groundwater Sea water intrusion .ppt (5)

Condensation Average Rainfall Average Annual and Monthly Precipitation – Average rainfall over one year period and monthly intervals and usually based on global atmosphere Precipitation Narration: The hydrologic or water cycle is the continuous flow of water between reservoirs at or near the earth’s surface. As water falls to the ground as precipitation, it may develop as surface runoff into nearby surface waters or infiltrate into the ground and become stored as groundwater. Water stored in open areas, know as surface water, can evaporate into the atmosphere. In addition, water used by plants for normal growth or transpiration is also returned to the atmosphere. Once in the atmosphere water can condense into clouds and precipitate as rain or snowfall, initiating the cycle over again. Water is a renewable resource that, managed properly, can sustain the activities in the watershed for an indefinite period of time. Animation: shows water cycle Consumption Groundwater Surface Water .ppt (6)

Storage Storage devices may be either above or below ground Different types include Storage Tanks Water Containers Lagoons or Lined Ponds Size based on rainfall pattern, demand, budget and area The collection device usually represents the biggest capital investment of an RWH system. It therefore requires careful design- to provide optimal storage capacity while keeping the cost as low as possible. While above-ground structures like tanks are easily purchased or made with a variety of designs, and water extraction is in many cases by gravity; they also are expensive, require more space and are prone to attack from the weather. Below-ground structures like cisterns, lagoons etc. are generally cheaper due to lower material requirements and unobtrusive. However, water extraction often requires a pump, contamination is more common, and present a potential danger to children and small animals if left uncovered. .ppt (7)

Establishing the need in India… A news article says that ground water levels in New Delhi are falling and RWH will become mandatory. .ppt (8)

SO AS WE ALL ARE THE HUMAN BEINGS AND ITS OUR RESPONSIBILTY TO SAVE OUR GROUND WATER LEVEL AND MAKE THEM RECHARGE AT TIME TO TIME BY RAIN WATER HARVESTING .ppt (9)

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