“Water is at the foundation of sustainable development as it is the common denominator of all global
challenges: energy, food, health, peace and security, and poverty eradication.” as defined by UN water website (Tess Russo, Katherine Alfredo , Joshua Fisher, 2014)
The basic necessities for a human survival and the access to them measures the life longevity. Water being the second most important element of the human endurance plays an important role in a man ‘s well being. The access to it is the question in the present world. Not everybody is fortunate enough to acquire good quality water to drink or for other basic household necessities. So the sustainable use of water is much needed in the present world scenario.
From table 1.1 we can identify that sustainable development in developing country ‘s urban area would require equity distribution of water without intermittent flow and should meet the future demands with flexibility. (Tess Russo, Katherine Alfredo , Joshua Fisher, 2014)
· Equitable Delivery
· System flexibility with growth
· Food security
· Expansion of irrigated area
· Supplemental irrigation
· Crop water productivity
· Protection of valued ecosystem services
Table 1.1: Primary Sustainable water management objectives Source: (Tess Russo, Katherine Alfredo , Joshua Fisher, 2014)
(i)Why do we have to talk about sustainable water management in urban design?
As mentioned above ,water being the most important factor for life survival, the water that we acquire from the resources are natural and we need to maintain the resource so that it does not get depleted as it is not good for the biological beings living in the environment. At a later stage, it disrupts the life cycle. Then we will have to depend on the other distant sources, which in turn is not economically sustainable. The social well being would diminish day by day as the major source of living is not being managed properly to reach the consumer. So we need to plan the resources properly to reach the consumer and that is why we need to think of sustainable water management in urban design.
(ii)Current scenarios at various levels of urban design
At National level – Even though India has good access to the natural resource of water but has only 4% of the worldwide surface water source. Whereas the country contains 16% of the total population in the world. The country is in a better position compared to the other nations, so on a brighter side we need to look out for better management of available resources so that we do not waste what we have access for . (Mengal, n.d.) According to Upali Amarsinghe, he predicts for 2050 that India cannot depend entirely on the groundwater resource for the future water demands, as they are getting depleted due to over- exploitation . (Amarasinghe, n.d.)
At urban city level – Chennai, capital of Tamil Nadu state, is a metropolitan city in India and is the fourth biggest metropolitan city in India comprising of around 1189 sq km area of Chennai metropolitan area(CMA). (CMDA, n.d.)The city has 100% supply connections for water supply but the supply is always infrequent. But the city always faces water scarcity even though there is annual rainfall of 700mm to 1100 mm. (Sethuraman, 2014 )
This essay highlights the water supply, demand and the water scarcity in the Chennai metropolitan area and how can the urban water supply management be sustainably developed by
1. Understanding the issues and demands
2. Look into the present government policies and regulations and the efforts taken by the water board for sustainable development .
3. Study BREEAM assessments to formulate solutions. Furthermore, it gives an insight on how can BREEAM assessment help in creating a checklist at various levels in the water management through design and monitoring process.
The above mentioned data would give a clear insight about the management systems and solutions could be formulated by suggesting policies or by revising the existing ones . Few methodologies and assessment criteria can also be utilized as guidelines to follow for a sustainable management in terms of equipment usage , monitoring systems etc.
2. WATER MANAGEMENT IN CHENNAI
Chennai has a shortage of perennial source of water and the following are the various sources of water supply.
1. Surface water : 3 reservoirs- Poondi, Cholavaram, Chembrambakkam and Red hills namely
2. Groundwater : Korataliar and Araniar basin
3. Distant sources : Telugu Ganga Project and Veeranam project
4. Desalination : 100 MLD plant in Minjur , North Chennai and 100 MLD plant at Nemmeli , South Chennai
5. Re-use : Secondary treated effluent from wastewater used for industries. (CMWSSB, 2017)
(i) Demand, supply and projection
According to the 2011 census, the CMA comprised of a population of 6.726 million and it is predicted that the population projection would be 7.44 million in 2018.The water demand in 2011 was 1042 MLD and expected demand would increase to 1594 MLD in 2018 for the CMA. The total water supply from the above- mentioned resources is 600 MLD. And the required amount is 1594 MLD. So there should be effective measures taken to meet the demands. (CMWSSB, 2016 )
Table 2.1: Population and demand Source: (A.Murugesan,N.Bavana,C.Vijayakumar,T.Vignesha, 2015)
(ii) Issues and challenges faced
1. Lack of Surface water
The CMA has no surface water resource as the existing rivers and basins act as flood carriers towards the sea and have an intermittent flow of water or are mostly waste or sewage carriers because they are polluted due to unauthorized encroachment near the river banks and due to no proper waste disposal lines. (CMWSSB, 2016 ). Due to the increase in population and unemployment because of urbanization , it has been witnessed that the encroachment levels have increased near the river banks as there is no proper shelter provided for the below poverty line population. This ,in turn, has lead to the settlements.
2. Depleting the groundwater source
In the years 1969 and 1987 around 6 well fields were identified IN CMA under the United Nations Development Programme hydrogeological study. The total design capacity of the wells was around 180 MLD all together, but as the time went by and due to the global climatic changes the monsoon ‘s periodic rainfall was affected and that in turn depleted the water levels which leads to only 30 MLD- current drawl. (CMWSSB, 2016 )
3. Sea water intrusion into ground water aquifers
Due to the unsustainable extraction of groundwater in the absence of surface water resources , it has been noticed that sea water has intruded up to 13 km inland. (CMWSSB, 2016 )
4. Lack of water and sewerage systems in the newly added areas in CMA
420 sqm radius of areas had been added to the CMA in 2011 and when these areas were considered , it had been found that the water and sewerage systems were not proper and the waste disposal were through the storm water drains , open spaces and road side drains .This had disrupted the existent water ways and stagnated the pipelines. The waterways were polluted leading to health risk. (CMWSSB, 2016 )
5. Non revenue water losses
The existing pipelines in CMA are chocked and the water mains have many leakage points because they get corroded and that leads to a lot of water loss leading to non accounted water loss. Around 35 % losses in water were identified in the distribution system. (CMWSSB, 2016 )
The following are the various challenges affecting the sustainable growth of the water management in CMA as identified:-
1. Water crises due to the increase in population due to urbanization , which in turn is increasing the water supply demand.
2. Improper water management in terms of pipelines and leakages leading to loss of non revenue water , this is due to the improper funding from the government to lay pipes coated with
3. Pollution of the available water resources due to encroachment near the river banks and also due to poor sewerage management in the newly added areas in CMA
4. Lethargic use of water from the demand side and the consumer doesn’t recognize the impact of depletion of natural resources.
5. Natural calamities and global climatic change – The Chennai city had recently faced two major water related calamities in December in consecutive years 2015, 2016. So the city needs to be prepared for such calamities so that water is not wasted.
3.GOVERNMENT POLICIES AND REGULATIONS – STEPS TAKEN FOR SUSTAINABLE URBAN DESIGN
Introduction of ground water regulation act – 1987 and amendment made in October 2002 . Under this regulation was made to sink new wells. Exisiting wells were registered.
Construction of check dams: Check dams were constructed in the years1991,1993,1995and considerable the water level increased from 10m to 25 m .
Rain water harvesting(RWH) : RWH was made mandatory in 2003. 4 methods were adapted , RWH in thatch roof , sloped roof , in sump well , in multistoried building. And Tamilnadu was the first state to achieve 100% coverage in RWH.
4.BREEAM AND SUSTAINABLE WATER MANAGEMENT
BREEAM is an assessment methodology which is widely dealt in UK and is known for its sustainable rating system which assess the sustainability of built environment ,construction and use and the surroundings which it dwells in. This standard is internationally accepted and adapted in various countries across the globe. (BRE, Global Ltd, 2017)
It is advised that BREEAM assessor or accredited professional should be appointed at an early stage in the project which would help the client achieve a target rating so that the design decisions would be more easy and changeable and also in terms of budgets and possible solutions . (BRE, Global Ltd, 2017) Since we have observed that new areas had been added to the CMA and their target for completion of the sustainable development is till the end of 2018 , that means that the project is still in its design stages and in the start of implementation stage .So we can propose changes in the existing regulations using BREEAM guidelines.
BREEAM Communities Technical manual is being used as a guide here for sustainable development because this guide focuses on large scale developments , communities . (BRE, Global Ltd, 2012)As we are focusing on major issues pertaining to a large level developments and areas – CMA, this guide would be more in a comparable range to achieve sustainable development .
RE03- WATER STRATEGY
Under RE 03 Water strategy assessment in BREEAM Communities technical manual , as this manual is for new developments , it aims to ensure that the water board and the developer(in our case the city development authority ) of the development should project the water consumption demands by considering the climatic changes in the future .A strategy is developed to meet the demands and a certain amount of space is established in the development according to the consumption levels. It also states that there should be some allowance kept considering the climatic changes and drastic events . Credits are achieved accordingly , if the above mentioned criteria are achieved and if the developer designs in such a way that water use is minimized by integrating necessary design strategies within the site. (BRE, Global Ltd, 2012)
Since Chennai is already a developed city and the city development authority had already designed it and identified the low lying areas and it has two major rivers flowing across the city , which are supposedly used as storm water run-off. So the reservoirs built are based on their geographical locations also. The chief Engineer of water resources department , R. Emaraj. suggests in increasing the capacity of the reservoirs by 5- 10 % by deepening them. (Lakshmi, 2017). During the floods in 2015 December (Varada) the city had witnessed massive over flow of water from the lakes which overflowed and flooded all the suburbs and the encroached land space along the river banks (which had number of unauthorized housings ) were majorly affected . So even though this development meets the criteria, as mentioned in the above paragraph , it has been observed that the city has unauthorized housings which needs to be shifted , or made authorized and establish in more permeable storm water drain systems in those areas so that the suburbs do not land up in a similar situation in the future.
LE03- WATER POLLUTION
Under land use ecology category , LE 03 – Water pollution in the BREEAM Communities technical manual it aims to protect the water table and the water resources from pollution and environmental deterioration. For this assessment , the drainage plan needs to be produced for the development and measures need to be taken to avoid water pollution. Also , appropriate amount of treatment needs to be provided to the sullage which flows in the storm water runoff . This is to ensure quality health from the poisonous hazards getting out. At the same time measures need to be taken to avoid infiltration of sullage contaminating the water table . SuDs manual is being used as a recommended guide for the risk assessments. (BRE, Global Ltd, 2012)
Chennai ‘s new added areas to CMA have very poor sewage treatment systems and this had led to the infiltration of the surface water systems and which in turn have made it unusable to use the natural water resource . (CMWSSB, 2016 ) So necessary steps need to be taken to work out the drainage systems at those points at which there are leakages so that there is no further sullage getting into the natural resources. Those points need to be repaired and at the same time the surface water needs to be treated so that it can be used now. We all know that is not a simple job as it includes a lot of manpower , time and money . As BREEAM aims for a sustainable development in terms of economy , society and environment , (BRE, Global Ltd, 2017)the CMWSSB need to come up with strategy to bring in all these aspects together . A disadvantage in Chennai is the political situation which is not providing a proper economical resource to allow the projects to run completely .Prof. Janakiraman president of the SACIWRS ,voices out that consecutive governments had not paid any attention towards the water bodies in the city and this has lead to structures destruction and depletion of ground water. (Lakshmi, 2017)The intermittent funding delays the project so the problems remain to be persistent .
LE06- RAINWATER HARVESTING
Under land use ecology category , LE 06 – RWH in the BREEAM Communities technical manual it aims to minimize water demand by using the storm water surface run off effectively. The assessment criteria states that credits are allocated based on the total hard surface in the site including roof and the RWH system is designed in according to BS8515 and BSEN 12056. (BRE, Global Ltd, 2012)
RWH system scheme was launched in Tamilnadu in 2001 and a movement was passed to make sure all built structures have RWH system compulsorily .Various techniques have been incorporated to provide RWH in rural and urban areas. So the CMA has fully equipped RWH system so that the ground water is recharged. (panchayats, n.d.)
WAT01 WATER CONSUMPTION
At a building level when the water demand and management is inspected, by increasing the efficiency of sanitary fittings , recycling systems and the RWH systems the demand for the potable water reduces. This assessment uses BREEAM Wat01 calculator to assess the efficiency of the water consuming fittings in the building, moreover this assessment awards credits if the performance is improved over the baseline performance as prescribed (Table 4.1).The domestic scale water consuming components need to be assessed to check their efficiency, which would be a part of the BREEAM Wat01 calculator. The greywater/ rainwater systems are made mandatory to be a part of the criteria to meet the assessment to attain credits .
No. of BREEAM credits
Precipitation zone 1
Precipitation zone 2
Precipitation zone 3
Table 2.1: BREEAM Credits available for percentage improvement over baseline building water consumption Source: (BRE, Global Ltd, 2017)pg 238
The precipitation zones are classified based on Koppen’s precipitation zone classification. (BRE, Global Ltd, 2017)
Fig 4.1: World map of BREEAM precipitation zones Source: (BRE, Global Ltd, 2017)pg247
Standard Wat01 method
This methodology is used for buildings which has accessibility to the data informing the usage of the water consuming components and the usage intervals and pattern. Here the baseline component efficiency is compared to the efficiency of the component in the building and credits are awarded based on the percentage improvement. Water efficiency of the water fitting components fabricated in the industry are used for the baseline efficiency , which are governed by the Water supply regulations. (BRE, Global Ltd, 2017)
Alternative Wat01 method
When the usage data and pattern of the water consumption of the building cannot be determined , this methodology is adopted. The following components are compared for the specification against the water efficient component consumption specification. (BRE, Global Ltd, 2017)
8. Washing machines
Since the building type is known , the weightage of usage of the component is analyzed in the BREEAM Wat01 calculator worksheet. The calculator used the BNWAT2261 to acquire the actual data for water consumption/day.(non domestic buildings)The calculator analyses the input data to arrive at a particular performance level and credits are awarded accordingly(Table 2.2)
Greywater or rainwater level achieved
Precipitation zones 1&2
Precipitation zone 3
Overall component level
Table 2.2: Credits awarded for the greywater performance level achieved Source: (BRE, Global Ltd, 2017)pg 241
For the rainwater systems it is advised that the country’s best practice systems should be adopted and the minimum requirements should be in accordance . (BRE, Global Ltd, 2017)
From this methodologies ,the following can be adopted to assess the management systems in CMA.
1. The water consuming components should be manufactured in accordance with the given criteria as mentioned to attain 12.5-65% improvement. (Table 2.1)The top manufacturers should take initiatives to manufacture more efficient water fittings.
2. The rainwater harvesting system which has been made mandatory in CMA should be used efficiently .
3. Policies need to be formulated to use particular rated fittings to reduce water demand.
4. Public awareness must be spawned to educate the importance of efficient water fittings.
WAT02 WATER CONSUMPTION
The water consumption assessment aims to ensure planned monitoring process so as to reduce the consumption. A credit is awarded for proper placements of water meters on water supply mains. In areas where the consumption is predicted to be more than10% of the demand supply , the equipments monitoring the supply should be placed in an easy accessible areas. A BMS should be adopted to monitor the consumption. (BRE, Global Ltd, 2017)
CMA has always faced problems with the water meter systems , as they are always submerged during the monsoons and it becomes worse when the meters are placed 5 foot deep in the ground. Since the meters are not automatic and it’s a laborious job , it cannot be monitored on an accurate basis. (Yuvaraaj, Chief Engineer, 2014)
The following can be adapted to the present scenario of flow meters in CMA:
1. BA can be integrated in BMS and can be adapted for the ease of work and monitoring process.
2. More efficient water meters with a better quality can be manufactured so that they would be in working concisions under extreme weather conditions.
We have been suggesting the aspects used in sustainable water management systems in a developed country against the developing countries. The sustainable development is addressed on a broader perspective and the sustainable growth of the urban development ensures the future demands are met as well. Whereas developing countries need to still build the adequate infrastructure to meet the demands and then build a sustainable concept to ensure intermittent water supply for the future development. Feasible options would be to lay proper lines for recycled water and also build water recycling plants in the localities so that the water is reused for locality development like gardening , or small scale industries , etc. (Tess Russo, Katherine Alfredo , Joshua Fisher, 2014)
we need to make sure we do not waste the water that we acquire from various sources from the demand side . From the supply side the water board should
This relates especially to the improvement of leaking distribution systems, the renewal of old water mains and thus the reduction of non-revenue water. Furthermore, the awareness about water conservation and water recycling must be created, especially regarding the use in industries, factories and big buildings such as hotels, institutions etc. Responsibility does not lie solely on the supply side of Chennai Metro Water Board, but also on the demand side.