Rainwater Harvesting and Sustainability of Water Supply
Santha Sheela Nair IAS (R) Vice Chairperson (Planning Commission), Govt. of Tamil Nadu 1
“ The duties of life cannot be discharged by any person without water as there cannot be any flowing of water without rain” Saint .THIRUVALLUVAR 1st century B.C.
THIRUKURAL
“OH GOD, Thank you for water You have blessed us with.� -UPANISHAD
Living beings originates from food and food originates from rain (The Bhagavad Gita, Chapter 3, Verse 19)
“A drop of water may spend 2 to 3 years in a river, 100 years in a glacier, between a few weeks and thousands of years in a lake. Some rains will evaporate off the ground at once. Some will soak into the ground, where it will be absorbed by the roots of the plants and then returned to the air through their leaves. And some may sink deep into the ground to form ground water, where it may stay for thousands of years. It is always the same water that goes around in this cycle. Some of the water you shower in today may have flowed down the Amazon a year ago or may have washed the feet of an Egyptian Pharaoh 3000 years ago.�
Water, Water, Everywhere: Kingfisher Kaleidoscopes, Esley House, London, 1994,Ed.John Jamieson et.al.,1994
Sources of Water Rain is the first form of water that we know in the hydrological cycle, hence this is a primary source of water. Rivers, lakes and ground water are all secondary sources of water. In present times, we depend entirely on such secondary sources of water. In the process, it is forgotten that rain is the ultimate source that feeds all these secondary sources and remain ignorant of its value. Water harvesting means to understand the value of rain, and to make optimum use of rain water at the place where it falls.
WATER CRISIS - WHY? Fresh water sources are being heavily exploited to meet the ever increasing demand of urban population. Fast rate of urbanisation reduce the availability of open surfaces for natural recharge of rain water. Failure of monsoon makes the situation worse Dependence on ground water increase during low rainfall. Large scale extraction results in depletion of water table and finally the wells become dry.
RWH AND SUSTAINABILITY OF WATER SUPPLY Rainwater is the ultimate source of fresh water on earth Rain fall in our country extends only for 2 to 3 months in a year and if we fail to conserve it, we will be left with no fresh water for the remaining period. Rain water if not harvested, runs off into the sea and gets wasted. Failure to harvest rain water, results in unsustainable systems of water availability for Agriculture Industry Domestic needs
What is Rain Water Harvesting? It is the activity of direct collection of rain water. Rain water can be stored for direct use or can be recharged into the ground water aquifer.
RAINWATER HARVESTING
RURAL RWH
URBAN RWH
1. Check Dams 2. Farm Ponds
Open Terrace
Open Space around the House
Direct Storage
Ground water Recharge
3. Lakes, Tanks & Ponds 4. Agriculture / Industry 5. Improved Crop Production
How Rainwater can be harvested? Broadly rain water can be harvested for two purposes. Collected and stored for ready use in containers/ponds/lakes etc. Recharged into the ground for withdrawal later.
Should Rainwater be stored directly or recharged? The decision to store or recharge rain water depends on the rainfall pattern of a particular region. For example, in places where rain falls throughout the year one can depend on a small domestic sized water tank for storing rain water, since the period between two spells of rain is short. On the other hand, in areas where the total annual rainfall occurs only during 2 to 3 months, the water collected during the monsoon has to be stored throughout the year which require huge volumes of storage containers and as well as some treatment processes. Therefore, considering the other benefits of ground water recharge, it is more feasible to use rain water to recharge ground water aquifers rather than for storage.
RAINWATER HARVESTING IS A TRADITIONAL WISDOM WHICH HAS BEEN SIMPLEST FORMS OF RAINWATER HARVESTING STRUCTURES
Tamil Nadu - Grand Anaicut dam across River Cauvery (Kallanai) ( built during 2nd century AD)
TAMILNADU
Tamil Nadu - Temple Tanks & Roof Water Collection Kancheepuram- 7th Century A.D
Rameswaram - 12th to 16th Century A.D
Roof Water Collection
Ancient Rainwater Harvesting structures - Rajasthan
Kunds/Kundis
A kund or kundi looks like an upturned cup nestling in a saucer. These structures harvest rainwater for drinking, and dot the sandier tracts of the Thar Desert in western Rajasthan and some areas in Gujarat. Essentially a circular underground well, kunds have a saucer-shaped catchment area that gently slopes towards the centre where the well is situated. A wire mesh across water-inlets prevents debris from falling into the well-pit. The sides of the well-pit are covered with (disinfectant) lime and ash. Most pits have a dome-shaped cover, or at least a lid, to protect the water. If need be, water can be drawn out with a bucket. The depth and diameter of kunds depend on their use (drinking, or domestic water requirements). They can be owned by only those with money to invest and land to construct it. Thus for the poor, large public kunds have to be built. 13
Earthen Check dams at River Arvari- Rajasthan Johad Johads are small earthen check dams that capture and conserve rainwater, improving percolation and groundwater recharge. Starting 1984, the last sixteen years have seen the revival of some 3000 johads spread across more than 650 villages in Alwar district, Rajasthan. This has resulted in a general rise of the groundwater level by almost 6 metres and a 33 percent increase in the forest cover in the area. Five rivers that used to go dry immediately following the monsoon have now become perennial, such as the River Arvari, has come 14 alive.
Ancient Rainwater Harvesting structures - Rajasthan Jhalaras
were human-made tanks, found in Rajasthan and Gujarat, essentially meant for community use and for religious rites. Often rectangular in design, jhalaras have steps on three or four sides. (Step wells)
Jhalaras are ground water bodies which are built to ensure easy & regular supply of water to the surrounding areas.
the jhalaras are rectangular in shape with steps on three or even on all the four sides of the tank . the steps are built on a series of levels.
The jhalaras collect subterranean seepage of a talab or a lake located upstream.
The water from these jhalaras was not used for drinking but for only community bathing and religious rites.
Jhodhpur city has eight jhalaras two of which are inside the town & six are found outside the city.
The oldest jhalara is the mahamandir jhalara which dates back to 1660 AD. 15
Ancient Rainwater Harvesting structures - Rajasthan Kuis / Beris Found in western Rajasthan, these are 10-12 m deep pits dug near tanks to collect the seepage. Kuis can also be used to harvest rainwater in areas with meagre rainfall. The mouth of the pit is usually made very narrow. This prevents the collected water from evaporating. The pit gets wider as it burrows under the ground, so that water can seep in into a large surface area. The openings of these entirely kuchcha (earthen) structures are generally covered with planks of wood, or put under lock and key. The water is used sparingly, as a last resource in crisis situations. 16
Ancient Rainwater Harvesting structures - Trans-Himalayan Region The Trans-Himalayan region of India consists of the cold deserts of Ladakh and Kargil in Jammu and Kashmir, and the Lahaul and Spiti valleys of Himachal Pradesh. Traditional recharge structure practiced here is the Zing.
Zings are water harvesting structures found in Ladakh. They are small tanks, in which collects melted glacier water. Essential to the system is the network of guiding channels that brings the water from the glacier to the tank. As glaciers melt during the day, the channels fill up with a trickle that in the afternoon turns into flowing water. The water collects towards the evening, and is used the next day. 17
Ancient Rainwater Harvesting structures - Gujarat Virdas are shallow wells dug in low depressions called jheels (tanks). They arefound all over the Banni grasslands, a part ofthe Great Rann of Kutch in Gujarat. They are systems built by the nomadic Maldharis, whoused to roam these grasslands. Now settled, they persist in using virdas.
The topography of the areais undulating, with depressions on the ground. By studying the flow of water during themonsoon, the Maldharis identify these depressions and make their virdas there. Essentially, thestructures use a technology that helps the Maldharis separate potable freshwater fromunpotable salt water. After rainwater infiltrates the soil, it gets stored at a level above the salty groundwater because of the difference in their density. A structure is built to reach down (about1 m) to this upper layer of accumulated rainwater. Between these two layers of sweet andsaline water, there exists a zone of brackish water. As freshwater is removed, the brackishwater moves upwards, and accumulates 18 towards the bottom of the virda.
Ancient Rainwater Harvesting structures - Maharastra
Bandharas are check dams or diversion weirs built across rivers. A traditional system found in Maharashtra, their presence raises the water level of the rivers so that it begins to flow into channels. They are also used to impound water and form a large reservoir. Where a bandhara was built across a small stream, the water supply would usually last for a few months after the rains. They are built either by villagers or by private persons who received rentfree land in return for their public act. Most Bandharas are defunct today.19
ROOF TOP RAIN WATER HARVESTING THE POTENTIAL Area of Terrace
: 100 sq.m. (Approx.1000 sq.ft.)
Average Rainfall per annum Volume of rainfall over the terrace
: 977 mm : 100 sq.m. x 0.98 m : 98m3 or 98,000 litres
Assuming about 60% of the rainfall is effectively harvested, Volume of available water will be
: 58,800 litres in a year : 160 litres/day
Sump required for harvesting Approx. cost of construction
: 5.8 m3 (dimensions - 1.8 x 1.8 x 1.8) : 0.1 million INR or ~ US $ 2527.
20
QUANTUM OF WATER AVAILABLE THROUGH ROOF TOP Rainfall (mm)
100
200
300
400
500
Roof top area (m2)
600
700
800
900
1000
1100
1200
1300
1400
1500
Harvested water from roof (m3)
20
1.6
3.2
4.8
6.4
8
9.6
11.2
12.8
14.4
16
17.6
19.2
20.8
22.4
24
30
2.4
4.8
7.2
9.6
12
14.4
16.8
19.2
21.6
24
26.4
28.8
31.2
33.6
36
40
3.2
6.4
9.6
12.8
16
19.2
22.4
25.6
28.8
32
35.2
38.4
41.6
44.8
48
50
4
8
12
16
20
24
28
32
36
40
44
48
52
56
60
60
4.8
9.6
14.4
19.2
24
28.8
33.6
38.4
43.2
48
52.8
57.6
62.4
67.2
72
70
5.6
11.2
16.8
22.4
28
33.6
39.2
44.8
50.4
56
61.6
67.2
72.8
78.4
84
80
6.4
12.8
19.2
25.6
32
38.4
44.8
51.2
57.6
64
70.4
76.8
83.2
89.6
96
90
7.2
14.4
21.6
28.8
36
43.2
50.4
57.6
64.8
72
79.2
86.4
93.6
100.8
108
100
8
16
24
32
40
48
56
64
72
80
88
96
104
112
120
150
12
24
36
48
60
72
84
96
108
120
132
144
156
168
180
200
16
32
48
64
80
96
112
128
144
160
176
192
208
224
240
250
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
300
24
48
72
96
120
144
168
192
216
240
264
288
312
336
360
400
32
64
96
128
160
192
224
256
288
320
352
384
416
448
480
500
40
80
120
160
200
240
280
320
360
400
440
480
520
560
600
1000
80
160
240
320
400
480
560
640
720
800
880
960
1040
1120
1200
2000
160
320
480
640
800
960
1120
1280
1440
1600
1760
1920
2080
2240
2400
3000
240
480
720
960
1200
1440
1680
1920
2160
2400
2640
2880
3120
3360
3600
21
RAIN WATER HARVESTING METHODS - URBAN
For Drinking Water (Roof top Rain Water Harvesting)
For Ground Water Recharge (Surface RunRun-off collection)
Suitable roof
Abandoned Dug well
Channel to collect water from the roof
Abandoned / running bore well & hand pump
Down pipe to divert water from channel to tank
Recharge Pit / Recharge pit with Bore
A Pre – collection filter
Recharge Trench / Recharge Trench with Bore
The storage tank
Recharge well
22
HOW JANAKI STOPPED GOING DOWN THE HILL TO FETCH WATER The New Indian Express of 19.07.2002 A four hour spell of continuous rain is sufficient enough to fill up eight pots, the family’s total water requirement. “Yesterday there was 15 minutes of rain but it was sufficient to make ganji (porridge)”, she says.
Splitting her saree into equal halves, Janaki uses the ensemble throughout the entire season. After the monsoon the model is dismantled and kept aside for the summer. She found a solution for water woes by making a saree into a Rainwater Harvesting structure.
SIMPLEST WAY OF RAINWATER HARVESTING
RAIN WATER HARVESTING - 1
Thatched Roofs
25
Rain Water Harvesting - 2
In Slums
26
Rain Water Harvesting - 3
27
Rain Water Harvesting - 4
In Schools 28
Rain Water Harvesting - 5
Roads
Multi storeyed buildings
29
Rain Water Harvesting - 6
30
Rain Water Harvesting - 7
Residence of Prime Importance – The Governor’s Residence
31
Rainwater Harvesting Methods
32
Developing Landscapes through roof top rain water harvesting A Classic Example
33
RAINWATER HARVESTING - AS A TOOL FOR FLOOD MITIGATION
34
ROAD SIDE RAINWATER CLLECTION THROUGH RECHARGE WELL
35
RAINWATER COLLECTION THROUGH STORM WATER DRAIN
36
Household Rooftop Rainwater Harvesting at Nalgonda District – Andhra Pradesh
Rooftop rainwater pipe Filter Chamber
Filter Chamber
Rooftop rainwater pipe
Filter Chamber
Rainwater storage tanks made up of Cement concrete well rings
Rooftop rainwater pipe Filter Chamber
Rainwater storage tanks made up of Cement concrete well rings
37
Modern Rainwater Harvesting structures - Rajasthan
38
Chennai Sustainability
• 1998 to 2003 – Non Conventional Sources
1996 - Recyling of Sewage 1998 – 2001 - Brackish water Treatment Plant – Local usage 2002 – 2003 - Rainwater Harvesting • 2004 – Adding of distant sources – Veeranam - 180 MLD • 2010 – Sea water Desalination plant - 100 MLD
39
IMPACT OF GROUNDWATER (REGULATION) ACT –SOUTH OF CHENNAI SOUTHERN COASTAL AQUIFER YEARWISE MINIMUM & MAXIMUM WATER LEVEL FROM 1983 - 2010 Drought 2004 2010
2007
2004
2001
1998
1995
YEARS 1992
1989
1986
1983
Drought 1987
0
DEPTH IN 'METRES'
1 2 3 4 5 6 7 8 9
Water level in m
Challenge – Depleting Ground water level in well fields Solution - Ground water (Regulation) Act Result
- Rise of water level from 8.00 m to 2.10 m - Stabilization of ground water level - Only Law in India, implemented in Chennai - Public Works Department difficult to enforce the law 40
SEA WATER INTRUSION STUDIES - 1990
LEGEND SEA WATER INTERFACE LINETO PONNERI
PULICAT
SPECIFIC CONDUCTIVITY AT DEEPER AQUIFER IN OBSERVATION WELLS (AROUND 30 M)
NORTH
BURRIED CHANNEL ZONE OF FRESH WATER INJECTION
70000
LOCATION OF INJECTION
60000
KATTUR LAKSHMIPURAM ANICUT
BAY OF BENGAL
VAYALUR
MINJUR WELL FIELD
MINJUR
E.C. VALUE IN MICRO MOHS / CM
SALT PAN
50000 40000 30000 20000 10000 0
1A
4A
5A
6A
10A 11A 12A 14A 15A
OBSERVATION WELL NUMBER
VALLUR ANICUT
TO CHENNAI
NANDIAMBAKKAM ATTIPATTU
PRIOR TO INJECTION OF RAIN WATER AFTER INJECTION OF RAIN WATER
41
CONSTRUCTION OF CHECK DAMS
Check dam along Cooum River
Check dam along Koratallaiyar River
42
Check dam along Adyar River
Construction of Check Dams – (1992 – 1995)
1. MELSEMBEDU
2. VELLIYUR
3 JAGANATHAPURAM
PANJETTY WELL FIELD KANNIGAIPER WELL FIELD FLOOD PLAINS WELL FIELDS CHOLAVARAM TANK POONDI RESERVOIR
MINJUR WELL FEILD
TAMARAPAKKAM WELL FEILD
REDHILLS RESERVOIR
POONDI WELL FEILD
CHEMBARAMBAKKAM TANK
PORUR LAKE
43
Impact on water level fluctuation due to construction of Check Dams
YEARS 1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
0.00
Year of Construction of Checkdam
DEPTH IN 'METRES'
5.00
10.00
15.00
20.00
25.00
30.00 Average water level in 'm' Melsembedu Average water level in 'm' Jagannathapuram
Average water level in 'm' Velliyur
44
Chennai‌ May 2002
Call for Roof top Rain Water Harvesting Provision of RWH structures is mandatory for availing new Water/Sewer Connections After this provision of RWH only 13% of the houses provided Rainwater Harvesting Amendments made in the Ground water Regulations Act / Building Rules for implementing rainwater harvesting 45
Chennai‌ 19th July 2002
Ordinance issued by the Govt. of Tamil Nadu on 19.07.2003 making it mandatory for all buildings in the state to have Rain Water Harvesting structures by 31.08.2003. 46
INTENSIVE IEC CAMPAIGN ON RWH Dissemination of information on RWH Establishment of Rain Centre Organisation of Seminars/ Workshop Massive rallies and Human Chains Advertisement through Papers / Dailies Booklets / Pamphlets Posters and Wall Paintings Door to Door campaign
47
INTENSIVE IEC CAMPAIGN ON RWH… Reaching out to the people Chief Minister’s appeal letter to the elected representative Empanelment of Service Providers Involvement of SHG’s, NGO’s Technical guidance offered by TWAD and CMWSSB on the lithology and soil types in different areas and the types of RWH needed . Celebrity endorsement & Films on RWH Count down in dailies
48
INVOLVEMENT OF MEDIA ‌ Regular coverage in newspapers, articles, press releases. Appeals to the citizens for rain water harvesting. Print & Visual media as forum for regular interactions between government, civic body and citizens. Success stories and achievements of rain water harvesting.
49
Threat of enforcement through Legal means
50
Water levels in 'mts'
Water level in 'mts' July '03
Velachery
Taramani
Guindy
Saidapet
K.K.Nagar
Virugambakkam
T.Nagar
Royapettah
Nungambakkam
Chetpet
Purasaiwakkam
Anna Nagar
Villivakkam
Pulianthope
MKB Nagar
Kolathur
Thiruvanmiyur
Besant Nagar
Mylapore
Chepauk
Chinthadripet
George Town
Vallalar Nagar
Tondiarpet
New Washermanpet
IMPACT ON RAIN WATER HARVESTING – WATER LEVEL Location of Observation wells
0.00
2.00
4.00
6.00
8.00
10.00
12.00
Water level in 'mts' Sep'12
51
Total Dissolved Solids in 'ppm' (July '03)
0 Velachery
Taramani
Guindy
Saidapet
K.K.Nagar
Virugambakkam
T.Nagar
Royapettah
Nungambakkam
Chetpet
Purasaiwakkam
Anna Nagar
Villivakkam
Pulianthope
MKB Nagar
Kolathur
Thiruvanmiyur
Besant Nagar
Mylapore
Chepauk
Chinthadripet
George Town
Vallalar Nagar
Tondiarpet
New Washermanpet
Total Dissolved Solids in 'ppm'
IMPACT ON RAIN WATER HARVESTING – WATER QUALITY
4000
3500
3000
2500
2000
1500
1000
500
Total Dissolved Solids in 'ppm' (Sep '12)
52
VOLUME OF RAINWATER COLLECTED IN CHENNAI CITY Average Annual Rainfall
-
1200 mm
Two third Rainfall in 3 months
-
800 mm
Total No. of Houses in City
-
5,00,000
Approximate Roof Area of a house
-
75 sq. mt
Quantity of water collectable in 3 months is: 5,00,000 x 75 x 1.2 x 2/3 x 1000 = 30,000 million litres If 75% of this water is harvested by the Households, Quantum of water harvested from Rooftop = 30,000 x 0.75 = 22,500 million litres or 22500000 Kilo litres
53 3
ECONOMICS OF RAINWATER HARVESTED Cost saved in Million Rupees, if other source of water used Surface water @ Rs.12/KL = Rs. 270 Million Ground water @ Rs.25/KL = Rs. 563 Million Desalinated Water @ Rs. 50/KL = Rs. 1125 Million
BENEFITS Better water availability in the lake Better ground water availability since no extraction or reduced extraction during rains Also helps in flood mitigation Storm water drains are relieved of load Less water problem throughout the year
Annually, the city saves 300 – 400 Million INR on recurring basis
54 4
Quality changes Before and After implementation of Rainwater Harvesting Values in ‘ppm’ during
Parameters
1994
1999
2002
2004
2007
2010
Total Solids
3325
1835
1785
1650
1500
1300
Chlorides as 'Cl'
989
580
410
380
360
320
Total Hardness
900
540
400
360
350
325
Conductivity
4890
2700
2550
2250
2100
1600
4890
6000
4000
1600 325
320
1300 350
360
360
380
1500
2100
2250 1650
400
410
540
580
900
1000
989
2000
1785
1835
3000
2550
2700
3325
Values in'ppm'
5000
0
1994
1999
2002
2004
2007
2010
year Total Solids
Chlorides as 'Cl'
Total Hardness
Conductivity
5
IMPACT ON RAINWATER HARVESTING - MYLAPORE TEMPLE TANK
TEMPLE TANK - DRY
TEMPLE TANK – WITH RAIN WATER
IMPACT ON RAINWATER HARVESTING - MARUDHEESWARAR TEMPLE TANK
TEMPLE TANK - DRY
TEMPLE TANK – WITH RAIN WATER
VADAPALANI MURUGAR TEMPLE TANK- WITH RAIN WATER
TRIPLICANE PARATHASARATHY TEMPLE TANK- WITH RAIN WATER
THIRUPPULLANI TEMPLE TANK- RAMESWARAM
THIRUPPULLANI TEMPLE TANK
SURFACE RUNOFF COLLECTION
IT IS RAINING ‌ PLEASE MAINTAIN THE RAIN WATER HARVESTING STRUCTURES PROPERLY Clean the Roof Top. Ensure there are no blocks or cracks in the rain water pipes Clean the percolation pit and the sand / brick / pebbles and refill in the pit Check that the rainwater reaches the gutter. Check the rainwater flows into the Recharge well. Remove the silt and debris in the Recharge well. Ensure that the Rainwater Harvesting arrangements made in your buildings are maintained properly so as to reap maximum benefit during rains For more details Contact: METROWATER Telephone No.: 28454080 Website: www.chennaimetrowater.tn.nic.in
61
Groundwater level up, thanks to monsoon rain - The Hindu -Nov 29,2006
UPBEAT: Open wells in houses across the city, including this one at Villivakkam, witnessed a considerable increase in water level since the onset of the northeast monsoon. CHENNAI : The heavy rain brought by the northeast monsoon has increased the groundwater level considerably, which has led to improved water quality in most areas. There has been a steady rise in groundwater levels by an average of 2 metres in the city this month. The change in the water level between October first week and November first week was recorded during a recent study, which monitored wells in 29 stations across the city. The results of the study, made by Chennai Metrowater and other government departments, has been put out by the State Ground and Surface Water Data Resource Centre, a wing of the Public Works Department. The city received about 898 mm of rainfall between October 1 and November 22, an excess of 67 per cent compared to the normal rainfall of 536 mm..Saidapet recorded the maximum increase in water level with 5 m. Localities including Villivakkam and Koyambedu, which fall under clayey areas, saw an increase of about 4 m during November November. Little Mount, Velachery and places around Raj Bhavan also showed a rise of 4 m in the water table. table A few areas including Kolathur, Chinna Kodungaiyur, Arumbakkam, Tansi Nagar in Velachery, Virugambakkam and Nungambakkam recorded a rise of about 3 m. There was a 2 m rise in the groundwater level in areas such as Ayanavaram, Sembium, Purasawalkam, Saligramam, K.K.Nagar, Anna Nagar West, and Kotturpuram. Tondiarpet, Parrys, MKB Nagar, Kellys, Chinmaya Nagar and Chetpet recorded an increase of about 1 m in the water level. level Three areas, Greams Road, Mandaveli, Royapettah, recorded the least rise of less than a metre.
Rainwater Harvesting raises City’s Water table - Times of India- March 23, 2009 CHENNAI: Since 2005, Chennai has been receiving during every monsoon about 160 cm of rain, 30 cm above average. The water reserves that were built up post-2005 thanks to rainwater harvesting (RWH) systems being implemented in the city in 2003 continue to yield. Wells in Besant Nagar, for example, which had gone fry before the 2005 monsoon monsoon, have sufficient water. The Thiruvanmiyur temple tank, dry for 13 years (19922005), is now flush with water, as is the Kapaleeswarar temple tank in Mylapore where, during the float festival in January this year, people were not allowed on the float because the water level was quite high.
Indeed, RWH seems to have helped raise the water table in Chennai. True, the city has had good monsoons since 2005, but 1996-97 were also years of bounteous rain but the temple tanks were never full of water. For 50 years up to 2000, the average rainfall in Madras was 130 cm cm, but in the first four years of the new millennium it was 25% less, with the deficit in 2003 being 40%. Residents who correctly implemented RWH systems in 2003 reported an appreciable increase in groundwater levels in 2005 2005. On average, the water table rose by 6-8 metres. A resident in Mandaveli said that she had never seen the water table so high in her 30 years there.
Although with effect from January 1, 1994 1994, plan approvals for all new buildings in the city were to be given only if the drawings showed rainwater harvesting (RWH) systems in place, most builders found some excuse not to follow the rule. It was only in May 2001 that the new government considered the aspect of RWH seriously and decided to raise public awareness before implementation. In October 2002, the TN Government Municipalities and Buildings Rules Act was amended to include RWH. In June 2003 2003, when the chief minister convened a meeting on RWH and found that no progress was made, the government promulgated an ordinance advancing the deadline of implementation to August 31 31. Metrowater then began a door-to-door campaign, targeting four lakh households.
Rise in Ground water level in Chennai says study - The Hindu, Jan 17,2011 The good rainfall in the last few years has helped in filling the temple tanks that are main sources of groundwater recharge. A view of the Marundeeswarar temple tank in Thiruvanmiyur. CHENNAI: The average groundwater level in the city has witnessed an increase by two metres in the past six years years. The quality of groundwater has also seen an appreciable improvement, according to a recent study of Chennai Metrowater. The average water table in Chennai was 5.42 m during 2005 2005. Successive years of sustained normal rainfall and maintenance of rainwater harvesting system have contributed to the steady rise in the level, according to water experts. The average annual rainfall recorded every year since 2005 was above 1,300 mm. A total of 759 observatory wells across the city were monitored for the study. The water quality has also improved significantly in the last few years. The level of total dissolved solids that ranged between 400 parts per million (ppm) and 1,800 ppm across the city in 2005 saw a marked decline last year with the TDS level ranging between 200 ppm and 900 ppm. ppm The permissible limit of TDS is 500 ppm. According to the study, there was a marginal rise in the water level in December 2010 compared to the previous year. Groundwater level was at 2..33 m in 2010 2010,, 0.25 m more than the level in the previous year. Sources at the water agency said there was now scope only for a marginal increase in the water table as it had almost reached its saturation owing to consistent rainfall. The dependence on groundwater had also come down as Metrowater has stepped up its daily supply. The water level in sandy areas such as Tiruvottiyur, Mylapore and Thiruvanmiyur rose by 0.85 m last year. The level in clay areas, including Perambur, Vadapalani and West Mambalam, increased to 2.24 m in December compared to 2.65 m during the same period the previous year.However, hard rock areas such as Guindy and Velachery recorded a slight decrease in the water table by 0.47 m last December. Local weather phenomenon was cited as reason for the dip in the level.
Rise in Ground water level in Chennai says study - The Hindu, Jan 17,2011 Success story: The rainwater harvesting system in Triplicane Parthasarathy Temple tank has proven successful. The rainwater from the streets is routed into the tank. CHENNAI: With another monsoon round the corner, the significance of proper maintenance of rainwater harvesting (RWH) structures and awareness levels among residents on harnessing water is back in focus. The rainwater harvesting resource persons in the city point out that this is the best time to check and prepare the RWH structures for better returns of the monsoon. Though most households in the city have installed such structures, their maintenance remains a question, say RWH resource persons. As there has not been any survey on the RWH structures maintenance except a few random checks made by Chennai Metro water’s Rainwater Harvesting Cell, several voluntary organisations stress the need to check the structures’ efficiency. A simple method suggested by the resource persons was to observe the percolation of water during rains or by pouring water into the structure. If there was an overflowing of water, the silt accumulated in the system needed to be cleared. A Metrowater official said most households in the city adopted roof-top harvesting system, which was the simplest and the best harnessing method. He suggested that the pipes connecting the rooftop and the recharge structures be checked for leakages. The filter materials, pebbles or gravel, have to be cleaned before the rains. Another layer of sand filter can be added for further purification of rainwater, he added. The RWH Cell provided free advice about the maintenance of the structures besides monitoring the water level and quality. It can be contacted at 28454080 28454080..
Quality of groundwater in city better this year – Total Dissolved Solids Lower Compared to 2009, - Times of India-Jan 29,2011 CHENNAI: The quality of groundwater as well as its level in Chennai has improved this year. Metrowater officials said that the groundwater level in all parts of Chennai is at 3.5m compared to last year's figure of about four metres. They also said that total dissolved solids in the water is lower than in previous years. In addition, the levels in reservoirs that supply drinking water to the city have also increased so there will not be a scarcity of water this year, they said. Quality of groundwater is based on the total dissolved solids, which is measured in parts per million (PPM). The minimum standard for drinking water is 500 PPM and the tolerable standard is 1,500 PPM. When the PPM is above 2,000, the water cannot be consumed by a human being. Soil in Chennai has been classified as sandy, clay and hard rock. Coastal areas have sandy soil, while areas such as T Nagar, Vadapalani and Annanagar have clay soil. Hard rock soil is found in south Chennai. Statistics collected by Metrowater officials in December 2010 show that the PPM of water in sandy soil in the city ranged from 200 to 600, 600 compared to last year's reading of 300 to 900 PPM. The PPM of water in clay soil ranged from 200 to 500 compared to last year's PPM of 300 to 1,500. The quality of ground water in areas with hard soil also improved with figures showing 200 to 600 PPM this year compared to 300 to 900 PPM before. "The quality of groundwater has increased this year due to good rain. The groundwater table has got recharged continuously and this has improved the quality of water," Metrowater officials said. The officials also said that rainwater harvesting initiatives have resulted in higher groundwater levels. The statistics also show that in December 2010, the groundwater level in sandy soil areas stood at 2.16m compared to last year's figure of 2.58m, an increase of about 0.40m. The groundwater level in clay soil regions has increased by about one metre in a year, standing at 1.88m compared to last year's 2.87m. However, the groundwater level has dropped in hard rock soil areas from 2.46m in 2009 to 3.21m in 2010. Officials said that the drop in groundwater levels in hard rock soil is due to fast urbanisation. In terms of water supply, as on January 24, 2011, the level in Poondi reservoir stands at 35 feet (29.8 in 2010), Sholavaram 17.86 (15.28 in 2010), Redhills 21.05 (16.32) and Chembarambakkam 22.16 feet (18.89). Officials said that Chennai has enough water to avoid scarcity, and also gets water from the Veeranam project. "In addition, we will also get desalinated water from Minjur," they said.
THE SOCIO-ECONOMIC IMPACT OF PEOPLE PARTICIPATION IN CITY WATER MANAGEMENT
Sustainability in Water Supply Meeting the Gap in demand & supply through rain water harvesting. Decrease in saline water ingression ingression. Drought proofing of the Metropolis. Massive sensitization and involvement of the civil bodies, local institutions, government bodies and citizens to “Conserve Water where It Falls�. At household level, drinking and domestic water demand was met through roof top water harvesting harvesting, thereby the households not taking supply from the Municipal authority / private suppliers. Movement from Water Scarcity to Water Security among the citizens /residents.
Savings in terms of power (pumping of water from UG sump to overhead tanks). Increased availability of water not only in the sump, but in wells in households, also augmenting the ground water recharge.
Improved quality of water water.
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Sustainable Water Supply in Agriculture Consume less water-intensive food products to the maximum extent possible. Reduce atrocious food wastage: Around 30% of the food produced worldwide is never eaten, and the water used to produce it is a loss. Produce more food with less water: Water productivity should be improved with the application of less water-intensive technologies, like sprinkler and drip irrigations. Further, proper land preparation (ploughing) and implementation of biofertilizers will reduce water requirements considerably. For each crop, the optimum water requirement should be identified and irrigation designed accordingly. Research should be encouraged for innovation of less water-intensive and highyielding seeds for different crops. The application of ‘marginal/second quality of water’ in agriculture should be encouraged, especially in water scarce areas. In this regard, treated domestic and industrial waste water has great scope. However, the safety (quality) of food items manufactured through effluent irrigation, and the health of the labourers who are working on the field, have to be guaranteed.
UNCONVENTIONAL METHODS OF GROUND WATER RECHARGE
Fracture seal Cementation (FSC)
Bore Blast Technique (BBT)
Jacket Well Technique (JWT)
Stream Blasting Technique (SBT)
Unconventional methods of ground water recharge are being adopted in Maharashtra and Gujarat, with an aim to create Rise in ground water table Formation of secondary aquifer in otherwise massive hard rock Diversion of nearby stream/sub-surface water to drinking water sources which are otherwise not recharged due to specific geological conditions
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Sustainable Water Supply in Industry Rainwater harvesting. Sewage water management and recycling. Watershed management. Community programs Water consumption monitoring. Recycling water from cooling towers Sewage water management Desalination
LEGAL INITIATIVES ON RAINWATER HARVESTING BY VARIOUS STATES
AMENDMENTS & IMPROVEMENTS IN TAMILNADU DISTRICT MUNICIPALITES BUILDING RULES – 1972.
• Provision
of
Rainwater
harvesting Structure in existing buildings
(Tiled,
Sloped,
Ordinary buildings and multi storied buildings) one year from the 11th Oct.2002.
• Separation of bath and wash basin water and reuse – multi storied and public buildings
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AMENDMENTS & IMPROVEMENTS IN GROUND WATER ACT OF 1987 Inclusion of additional villages to the list of scheduled villages in the Act. Revision of fine amount Rs.1,000/- to Rs.5,000/ Mandatory Rainwater buildings.
requirement Harvesting in
from of all
No extraction of ground water for swimming pools, industrial uses and other non-potable purposes. Restrictions to the depth of bore wells. No water body, Public or Private, to be utilized for any other purpose, such as land fill, garbage dumps, building activities etc., 73
Ordinance by Tamil Nadu Government - 2003
Ordinance issued by the Govt. of Tamil Nadu on 19.07.2003 making it mandatory for all buildings in the state to have Rain Water Harvesting structures by 31.08.2003.
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Legal initiatives by various states
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Legal initiatives by various states
26
Legal initiatives by various states
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Conservation of water for Sustainability
(180 lts)
(227 lts)
(18 lts)
Recycling and Reuse of Waste water for Sustainability
Sustainability in Water Supply - Recycling of Sewage - 1996 -
1. Supply of secondary treated sewage to CPCL & MFL Ind. from Kodungaiyur STP. 2. Supply of sewage to M/s. GMR Vasavi Power Corporation Total
36.0 mld 5.0 mld 41.0 mld 87
WASTE WATER OF THE CITY RECYCLED & REUSED Treated Sewage sold for
Treated Sewage used for
Treated Sewage pond for
INDUSTRIAL USES
AGRO FORESTRY - CITY
PISICULTURE
- MAKING A VIRTUE OUT OF NECESSITY WASTE WATER IN HOUSEHOLDS APARTMENTS BLACK WATER
GREY WATER
GREY WATER
CITY SEWERAGE SYSTEM
RECHARGE OF GROUND
Simple Household filter with disinfection- (if necessary)
GREY WATER(NON DOMESTIC USES)
A.C Cooling system / LANDSCAPING / KITCHEN 38 GARDEN
Sustainability in Water Supply - Agro Forestry
Over 1000 Acres of lush greenery like Casuarinas, Bamboo, Teak and Eucalyptus were product of Secondary treated sewage, In - tune with International standards
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Sustainability in Water Supply - Pisiculture
Multi fish culture (Murrels, Chenna Kuchuva, Gilabia and Catch fish) introduced in Villivakkam Sewage Treatment Plant in Chennai,Tamil Nadu, Chennai 90
Bringing Sustainability through RWH Surface Water and Ground Water exploited beyond reasonable limits.
Rain Water yet to be tapped effectively. RWH important for Drinking water Agriculture Industry
Bringing Sustainability through RWH Sustainability in Water Supply depends on conjunctive use of water resources Ground Water Surface Water and Rain water Instead of dependence on one source of water supply. All Water Supply Programmes to prepare a Water Budget and a Water Audit, Audit accounting for every drop of water, whatever the sources and ensure sustainability.
Sustainability in Water Supply
Let us protect and conserve our Water Sources
“Underneath the verandah in front of the room in which the Mahatma was born, in the space enclosed by the three wings of the house, is an underground reservoir, 20 feet long, 20 feet wide and 15 feet deep, with a capacity of 20 thousand gallons, for storing rainwater for domestic use. The well water in Porbandar, owing to its vicinity to the sea, is brackish, hard and unfit for cooking. Rainwater was, therefore, collected and stored in the underground reservoir for use the year round. The terrace on the top floor, carefully washed before the first monsoon showers, served as catchments for the water, running down a pipe straight into the tank. A heap of lime at the mouth of the pipe served to filter and purity the water�. In this house five generations of Gandhis lived and prospered.
- Mahatma Gandhi Vol 1(The Early Phase) by Shri Pyarelal 94