Showing posts with label water harvesting. Show all posts
Showing posts with label water harvesting. Show all posts

Thursday, October 3, 2019

Geological report on importance of rain water harvesting in selected areas of Ranchi city,India.

Dependency on groundwater for drinking and domestic purpose has increased.

By

Dr. Nitish Priyadarshi
Geologist.
nitish.priyadarshi@gmail.com


Introduction:

Water is essential for life- all living organisms contain water. In fact most living organisms consist of over 60 percent water.

Through out his brief history on earth, man has depended on three basic natural resources for his survival: air, land and water. Of these three, none has been more abused and neglected by man than water. Yet without water, the land produces nothing; without water, life vanishes from the face of the earth. Civilizations arose and have prospered for millennia where water was abundant. The Nile valley is a prime example. When water disappeared, civilizations withered and died. Mesopotamia is a classic example.

The utter human dependence on water is exemplified by the fact that man can survive for five weeks without food, but he dies after only five days without water. If the water supply of a human being is cut off for just a few days, he will die of dehydration long before the water is completely evaporated from his body. Water vapor is lost with every breath, and we cannot avoid breathing.
In recent years due to increasing contamination of surface water bodies, dependency on groundwater for drinking and domestic purpose has increased many fold. But these water sources are now badly affected with global warming. Groundwater is depleting day by day due to effect of rising temperature and urbanization.

The excess soil moisture that saturates subsurface soil or rock and migrates downward under the influence of gravity. In the literal sense, all water below the ground surface is groundwater; in hydrogeologic terms, however, the top of this saturated zone is called the water table, and the water below the water table is called groundwater.
Ranchi the capital city of Jharkhand state of India is located at 23.350 N and 85.330 E. The total area covered by Ranchi-Municipal area is about 141 square kilometers and the average elevation of the city is 645 m above Mean Sea Level (MSL). As of 2001 India census Ranchi had a population of 846,454.

Water supply, in adequate quantity and at desirable quality, is essential for any sustainable urbanization. Water supply in Ranchi dates back to more than 50 years ago.

There are three main dams ( Hatia, Rukka, and Kanke dam) from where the water is supplied to the city. Surface water is always vulnerable to pollution. People of Ranchi are dependent more on purer source like groundwater. Of the total consumption more than 60% comes from groundwater storage. Due to increasing population more pressure has developed on groundwater from the aquifer beneath the city.

The process of urbanization and industrialization from last 20 years has caused changes in the water table as a result of decreased recharge and increased withdrawal. Many of the small ponds which were main source of water in the surrounding areas are now filled for different construction purpose affecting the water table. Lots of DEEP- BORING in the Ranchi city has also forced the water table to move down as well as Ranchi plateau.

Groundwater in Ranchi city:

Groundwater in Ranchi city is mainly stored here in secondary porosity features or void spaces developed as result of weathering, fracturing, jointing, shearing or faulting phenomena. The gneisses and granitic rocks with associated schists and quartzites constitute the main consolidated rock terrain of Ranchi district.

Major portion of Ranchi city which is part of the Chotanagpur Plateau occupied by hard rock which are devoid of primary porosity and occurrence and movement of groundwater is controlled by the joints, fractures and fissures present in them.

During the long span of geological history these rocks have been deformed and tectonised in many ways including deep erosion.

In Ranchi city water table in the consolidated formations is now at its lowest from April to June. Water table is at its highest peak during August, gradually stabilizing in the month of November.

Sources of groundwater recharge in Ranchi city and the other parts of Jharkhand State is the vertical percolation of rain water. Although city experiences about 1000 to 1200 mm rainfall annually, the rate of vertical percolation is hindered by the presence of highly weathered and metamorphosed rocks. The Ranchi plateau gradually slopes down towards south east into the hilly and undulating region of Singhbhum. Due to this uneven topography the rain water are lost through surface runoff resulting in less water percolation below the surface. The thin soil layer of Ranchi plateau which is becoming more thin due to weathering is gradually loosing its water retaining capacity, Moreover, present land development practices in the recharge area and natural canals or rivulets in and around the city is also reducing the natural recharge significantly. More than 40% of the rain water is lost in the form of surface runoff. The rate of decline ranges between 1m/year to 5m/year at different observation locations within the city.
As Ranchi is becoming one of the important business center in Eastern India there is a rampant increase in construction and expansion of city. Due to inadequate water supply from the dams, dependency on ground water is increasing. Over pressed zones are Upper Bazar, Main Road, Ratu Road, Piska More, Chutia, Hindhpirhi, Circular Road, Burdwan Compound, Lalpur and Harmu Road.

Objective:
The main objectives of Rain Water Harvesting are:-
• Increasing the availability of ground water during periods of requirement.
•Preventing depletion of ground water reservoirs in areas of over exploitation.
Improving quality of ground water through dilution.

Rainwater harvesting is the collection, storage and injecting precipitation  down in the earth of  for later human use. This project focuses on the selection of the site and rainwater harvesting system located at the different rickshaw pullers garage located in different areas of Ratu road and Piska more in Ranchi city. The information collected  from this project will be used to build a template for designing a rain water harvesting system that can be placed in the selected areas.


                                    Fig.1 Depletion of ground water.


                                  Fig. 2. Structure of rain water harvesting.


Fig.3. Depleted water in a well in Piska More, Ranchi.

Rickshaw pullers are the most affected people as they are more dependent on surface and well water which is polluted and gets dry in summer season.


Till about thirty years back, the areas surveyed used to be unpaved and the rain falling on these areas would percolate into soil and remain there for being drawn through shallow open wells. With the proliferation of flat complexes, these areas been covered, resulting in stopping of percolation of rain water into the soil. But on the other hand the use of ground water has risen immensely. With Increase in the number of deep bore wells, the shallow wells started drying up. The reason is that no sincere attempt was made to re- establish the ground water table to its original level during monsoons.
Rooftop rain water harvesting was suggested in the surveyed areas. Out of 30 sites 10 sites were selected as the rickshaw pullers were using dug well waters for their daily purpose. Rooftop catchments is  the most basic form of this technology, rainwater is collected in simple vessels at the edge of the roof. Variations on this basic approach include collection of rainwater in gutters which drain to the collection vessel through down-pipes constructed for this purpose, and/or the diversion of rainwater from the gutters to the settling  tanks/percolation tank or absorption tank  filled with sands and cobbles and pebbles working as water filters. As the rooftop is the main catchment area, the amount and quality of rainwater collected depends on the area and type of roofing material. Reasonably pure rainwater can be collected from roofs constructed with galvanized corrugated iron, aluminum or asbestos cement sheets, tiles and slates.  Roofs with metallic paint or other coatings are not recommended as they may impart tastes or color to the collected water. Roof catchments should also be cleaned regularly to remove dust, leaves and bird droppings so as to maintain the quality of the water.
Settling tanks for collecting rainwater harvested using guttering may be either above or below the ground. Precautions required in the use of se tanks include provision of an adequate enclosure to minimize contamination from human, animal or other environmental contaminants, and a tight cover to prevent algal growth and the breeding of mosquitoes.




Sr.No
Garage Name
Garage owner name
Address
No.of rickshaw pullers staying  in the garage
Water Harvesting status
Remarks
Date of visit
1
Vijay
Vijay Tirkey
Near Krishi Bazar, Pandra, Ranchi
50
Yes; Important

29-01-2018
2
Amit
Amit kr. Bhagat
Piska More
70
Yes; Important

29-01-2018
3
SLK
Suresh Kachhap
Piska More
15
No
Shed not much and well is not owned by owner but garage owner has himself made some water harvesting system.
29-01-2018
4
Pawan
Pawan Sharma
Piska More
40
Yes

29-01-2018
5
BPK
Suresh
Karam toli
40
No
Has naturally available water resources which maintains the water level.
29-01-2018
6
JPB
Jagdish Bagla
Piska More
20
Yes; Important

30-01-2018
7
Guddu
Rajiv Agarwal
Near Uphar cinema, Ratu road
30
No
Consist of self built water system which maintains water level
30-01-2018
8
Mitu
Jayant Agarwal
Near Uphar cinema, Ratu road
30
No
Land too low so naturally land absorbs water, sheds are not available in much
30-01-2018
9
MPS
Madhukar Singh
Near Pahadi Mandir
25
No
No well; no boring and monthly rented land
30-01-2018
10
Sunil
Sunil Yadav
Near Pahadi Mandir
50
No
Less possibility of holding rain water
30-01-2018

Acknowledgement:
This survey was carried out with the help of Mrs. Aprajita Mishra and Smita Dasgupta of Maitri India, Ranchi.



Tuesday, April 8, 2008

MINE WATER CAN BE TRAPPED TO QUENCH THIRST- SPECIAL REFERENCE TO JHARKHAND STATE OF INDIA.

MINE WATER CAN BE TRAPPED TO QUENCH THIRST- SPECIAL REFERENCE TO JHARKHAND STATE OF INDIA.
"Catch Water Where it Falls"
By
Dr. Nitish Priyadarshi





Fig.1 Sufficient amount of water present in coal mines of NK Area of Jharkhand.

Fig.2 Other mine flooded with water

Fig.3 Satellite photo showing mine water in North Karanpura Coalfield of Jharkhand State.

Fig.4 Water in stone mine near Ranchi city.

Nature has been issuing warning signals like steep decline in water table, stoppage of base flow in streams and drying up of a large number of open wells and drilled bore wells.
In Jharkhand water underground few years ago had remained a precious resource to be tapped in times of need when all other sources of water had failed. This is no longer the case. The reckless way in which the people of Jharkhand are drilling more and more number of wells, drill deeper and deeper into the ground and withdraw water without exercising any restraint for domestic and commercial buildings and flats, shows gross abuse. Great damage has already been caused and any further abuse of this resource will result in water crisis.
Formerly the drinking water requirement of Jharkhand State was met by the construction of tanks, ponds and wells by the people themselves who also take care to keep these structures in good repair.
Tanks, ponds have been allowed to fill with silt and remain almost dry during the summer season and with no source of recharge, well become dry just after the winter season. You can easily imagine the situation in the peak summer season. Drying trend starts from February itself. Land in many parts are become bare due to depletion of ground water.
In the type of meteorological conditions prevailing in Jharkhand where rainfall is restricted to about three to four months in a year. Major dams are not capable of storing more than 10 to 20 % of the rain water that falls in their catchment area because of the filling up of silt and clay from last several years which has gradually shallowed the dams. The annual rainfall of Jharkhand is 1200 mm.
Taking note of the pattern of rainfall and geology of the state, water conservation through numerous large and small ponds is a much better alternative for storing rain water.
Idea is that catch rain water where it falls, store it and make use of it for your needs.
The State of Jharkhand, although claims to be a store house of minerals of India, is not so reach in water resources. Most of the area is occupied by the hard rock, which is in general protracted drought prone areas.
During my research in the coal fields regarding trace elements in coals, I saw many abandoned open coal mines filled with mine/rain water. All the mine waters are discharged into the near by Damodar river and its tributaries or left useless. All the communities especially tribal people are dependent on the most contaminated Damodar river water for drinking and other uses during peak summer season. Even the Damodar river get dry up during the summer season. Ground water levels are fairly deep, therefore scant availability. According to the reports millions of gallons of water have apparently flooded abandoned underground as well as open coal mines in the area while the coal filed is generally short of water.
Same situation I have seen around Ranchi city where there are sufficient numbers of abandoned stone mining filled with rain water and the local people use it for washing clothes and bathing. If proper management can be implemented like water quality monitoring and installing small filter plant around such mines at least local communities can be supplied with safe drinking water.
Regarding coal mines water, water can be used for both drinking and for irrigation. Especially during summer season, where every summer is a nightmare. Heat, coal dust and shortage of water create an unbearable cocktail in summer, when people in the coal field have to often walk several kilometers for a bucket of water, stand in long queues and occasionally fight with others for a just share of the water.
Only problem is the presence of suspended solids and heavy metals in the water. Water of the mines are not acidic as found in my research work. Heavy metals which were found in mine water in the north Karanpura coal field are arsenic, iron, zinc, manganese and fluoride. Among these arsenic was present in very trace amount. Problem is with manganese and fluoride which are in bit higher range.
It can also be used as the potential to serve as cooling water sources for electric power plants. Mine pool water will have to be treated to some degree, prior to use in a power plant’s cooling.
To me these metals can be minimized by primary and secondary treatment. When compared to Damodar river, these mine waters are more safe to consume after treatment.

Treatment technologies for pH adjustment, removal of TDS, dissolved metal ions, and variables found in mine water are well established.
An example of a treatment system that might be used for the treatment of mine water includes the following process units.
• Clarification to remove settleable solids
• Horizontal precipitator, coagulation, and flocculation for metals removal
• Multimedia filtration, ion exchange, and carbon adsorption if necessary to remove low
TDS

In a 1998 report, the Central Pollution Control Board of India classified the river as ‘D’, or heavily polluted. It means the water can only support some hardy variety of fishes, it cannot be used drinking or bathing. Damodar and its tributaries resemble large drain carrying black, highly turbid water. The total suspended solid (TSS) count at most places along the upper and middle stretches of the river is 40-50 times higher than the permissible limit.
In areas like Dhanbad, Giridih, Bokaro, Hazaribagh and Chatra, there is a tremendous requirement of water on the ground but perennial sources like river are very few and groundwater levels are fairly deep, therefore, scant availability. But water in the abandoned mines are within easy reach and can be turned to our advantage.
Regarding granite stone mines, there are many abandoned mines in Ranchi, Pankur, Palamau, Singhbhum districts etc. Rain water can harvested in such open mines. As compared to coal mine water, stone mine water are less polluted. It can fulfill the demand of local community. Joints and fractures present in granite mines can also help in recharging groundwater of the area.

There is no other way. ‘Catch Water Where it Falls’ should be the slogan. There is no need to go in search of water. It is there when you want it. Develop the ingenuity and skill to catch it, store it and make use of it wisely without wasting a single drop.
Dr. Nitish Priyadarshi
Geologist