Rainwater Management. Dr. Iftikhar Ahmad. College of Earth and. University of The Punjab Lahore

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1 Rainwater Management in Major Cities of Punjab Dr. Iftikhar Ahmad College of Earth and Environmental Sciences. University of The Punjab Lahore

2 Need For Rainfall Harvesting in Urban Areas of Punjab Groundwater reservoirs have been declining in urban areas due to rapid urbanization. It is a major and valuable source of water supply in Pakistan. Excessive use of groundwater is causing deterioration of water quality and drying up of water wells. Continuous over-draft has resulted in excessive groundwater abstraction, so that sweet water becoming scarce in urban areas of Punjab Province. Up-coning of deep saline water has started in some parts of Punjab. There is a need to realistically estimate and manage water resources for sustainable development.

3 Purpose Storage of rain water on surface for future use. Recharge to ground water for sustainable water supply in urban areas.

4 Benefits of Use and Recharge To enhance the recharge for sustainable ground water yield in urban areas where over development has depleted the aquifer. Utilization of rainfall runoff, which h is going waste to sewer or storm water drain. Storage of excess surface water for future requirements. As surface water is inadequate and of poor water quality to meet our demand, we have to depend on ground water. Due to rapid urbanization, infiltration of rainwater into the sub soil has decreased and recharge of ground water has diminished. With excessive water to improve the vegetation cover and reduce urban flooding. To raise the water levels in water wells that are drying up. To remove bacteriological and other impurities from sewage and waste water so that water is suitable for reuse. To improve the quality of existing Ground Water through dilution. To reduce power consumption. (Source: Rainwater harvesting and conservation manual (2002) Consultancy services organization, Central public works department, New Delhi)

5 Selected major Cities in Punjab Name of city Population (million) First Stage Second Stage Lahore Faisalabad 2.83 Multan Gujranwala Rawalpindi Sargodha 0.876

6 Location of Rainfall Stations in Punjab Source: Pakistan Meteorological Department, Lahore

7 Source: Google Maps, 2013 Location of Lahore

8 Lahore Rain, 12 August 2011

9 Urban Flooding Lahore

10 Under Pass During Rain

11 Source: Google Earth, 2013 Location of Lahore

12 Location of Lahore

13 Location of Lahore

14 A Typical System from Roof Top Source: Eldho T I Integrated Watershed Management & Rainwater Harvesting Department of Civil Source: Eldho T. I., Integrated Watershed Management & Rainwater Harvesting, Department of Civil Engineering, Indian Institute of Technology Bombay/ India

15 Lahore Climate and Rainfall Mean Monthly Rainfall at Lahore ( ) infall (mm) Mean Rai JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Data source: Pakistan Meteorological Department, Lahore

16 Lahore Climate and Rainfall Data source: Pakistan Meteorological Department, Lahore

17 Lahore Climate and Rainfall Data source: Pakistan Meteorological Department, Lahore

18 Lahore Climate and Rainfall Data source: Pakistan Meteorological Department, Lahore

19 Initial Findings Selected pictures of Lahore city show that a large number of roof tops are available for storage of rain water on surface for future use. The earth maps depicted that pockets of useful areas are available to make arrangements for recharge to ground water for sustainable water supply in Lahore Rainfall graphs and selected pictures of flooding in Lahore city show that plenty of rainwater is available for rainwater harvesting. Temperature graphs show that evaporation losses during rainwater harvesting need to be calculated and subtracted to determine net water available.

20 Faisalabad

21 Source: Google Earth, 2013 Faisalabad

22 Water Pollution in Faisalabad

23 Water Pollution in Faisalabad Source: Scott et al. (2011) Wastewater Use in Irrigated Agriculture, Coordinating the Livelihood and Environmental Realities

24 Faisalabad Climate and Rainfall Mean Monthly Rainfall at Faisalabad ( ) Rainfa all (mm) Mean JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Data source: Pakistan Meteorological Department, Lahore

25 Faisalabad Climate and Rainfall Annual Rainfall at Faisalabad ( ) Rainfall (mm) Data source: Pakistan Meteorological Department, Lahore

26 Faisalabad Climate and Rainfall Maximum and Minimum Temperature at Faisalabad ( ) Temp perature (Degr ree C) Maximum Minimum JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Data source: Pakistan Meteorological Department, Lahore

27 Initial Findings Water pollution is one of the major issue to be solved through dilution of fresh sweet rainwater or its direct use through storage of rain water on surface. Some parts of areas where groundwater is shallow or water logged need to be investigated. WAPDA has already taken measures in such areas to solve problem. Rainfall graphs show that enough rainwater is available for rainwater harvesting. Temperature graphs show that evaporation losses during rainwater harvesting need to be calculated and subtracted to determine net water available.

28 Source: Google Earth, 2013 Multan

29 Source: Google Maps, 2013 Location of Multan

30 Multan Climate and Rainfall Mean Monthly Rainfall at Multan ( ) Rain nfall (mm) Mean 0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Data source: Pakistan Meteorological Department, Lahore

31 Multan Climate and Rainfall Annual Rainfall at Multan ( ) Annual Rainfall (mm) Data source: Pakistan Meteorological Department, Lahore

32 Multan Climate and Rainfall Maximum and Minimum Temperature at Multan ( ) 60 Tempe erature (Degree e C) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Maximum Minimum Data source: Pakistan Meteorological Department, Lahore

33 Initial Findings Water pollution and water shortage are major issues to be solved. Rainfall graphs show that mean annual rainwater available for rainwater harvesting is 195 mm. It is low as compared to Lahore and Faisalabad. Therefore careful planning for rainwater harvesting will be required. Temperature graphs show air temperature is quite high in p g p p q g this city. Evaporation losses would be high and need to be calculated and subtracted to determine net water available.

34 Conclusions Rainwater harvesting in Urban areas is very important for sustainability of available water for future use. Generally large rainwater resource is available to cater the water. The recharging of ground water to maintain the declining aquifer levels in urban areas of Punjab can be done through rainfall management. Rainfall harvesting should be included in water polices. Some best design of structures should be tested in urban areas before to use. Evaporation losses need to be calculated and subtracted to dt determine net water available ilbl for exploitation. ti

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