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Revitalising Adyar River

Water Sensitive Urbanism

Adyar, Chennai

Adyar or Adayar is a large neighbourhood in south Chennai. It is located on the southern banks of the Adyar river. It is bounded by the Buckingham Canal to the west, Thiruvanmiyur to the south and Besant Nagar to the east. 1916-Britishers called it chengalpattu river since it came from that direction. It originates near the Chembarambakam lake.

Glimpses of the significant past

1746 - Battle of Adyar

Battle of Adyar happened in Quibble island where the French took charge. French won over the nawab of Arcot with just 200 soldiers against 10,000 siphais of Arcot.

1840 - Elphinstone Bridge

11m wide bridge was the first bridge to be built. Was named after governor general of India. Before the bridge was built people used to walk and cross the bridge when there is no water in the river

1863 - Quibble Island cemetry

The cemetery was once exclusively used for British burials, the cemetery was opened to the - public after the end of British rule in India, and is now nearly at capacity.

1879 - Theosophical society

The world headquarters was shifted to Bombay. Madame Blavatsky purchase this place in huddlestone gardens with 27 acres. The Occult room Adyar’s first shrine room was built.

Figure Ground Map

In the case of Adayar the urban solid spaces are Residential, Commercial, Mixed used, institutional, Religious, Hospitals, etc., and Void spaces are Parks Lawn, play grounds, Gardens, Rivers estuary., etc

Vegetation Map

Trees are extremely adequate in Gandhi Nagar, Anna Sathya Nagar MRC Nagar and the Strech of theosophical society and Besant Gardens. Kasturi bai Nagar, Shastri Nagar, Karpagam Gardens has very sparse vegetation.

CRZ Map

As per the CMA Coastal management plant, The study area contains CRZ II (Developed land areas close to or upto within the existing municipal limits)and CRZ IA (Ecologocally sensitve areas)

Political Map

The Adyar zone covers an area of 135 sq km. The study area is comprised of 3 wards, namely wards 175, 173 & 176. These 3 wards altogether cover an area of 22 sq km.

Ward 173

Ward 175

Ward 176

Land Use

The study area is vastly dominated by residential areas (such as Gandhi Nagar, Sathya Nagar & Besant Nagar). And also has sufficient Institutional and commercial spaces, predominantly along Sardar Patel road & Greenways road.

Site Population

The total population of the study area would be one lakh. The population of wards 173, 157, 176, 172 & 181 were 95325, 86510,75440, 90019 and 89585 respectively. Ward 176 had less number of houses as most of the land was occupied by Theosophical society.

Change in the course of the river

Polllution maping

Study Area

The river starts receiving industrial effluents, primarily from tanneries located near pammal. Downstream nandanbakkam, the river recieves significant municipal waste waters.

2015 Flood Inundation map

The major reason for Chennai flood happened during 2015 is because of the improper master plan, encroachment on the catchment areas, illegal constructions, choking of water exits and badly planned or unimplemented projects. During the olden days, Mambalam tank acted as a catchment area & received the excessive flood water. But these catchment areas were wiped out of existence due to the rapid increase in urbanization.

Fauna

Region of higher methane effluence

A total of 143 species of fish, amphibians, birds and reptiles have been seen in the park. More than 85 different kinds of birds, including rare black bittern, cinnamon bittern, black-winged kite, and many others have been spotted by ornithologists in the green expanse.

Major Issues

The banks on Malligaipoo nagar are severely polluted by solid & human waste and it stinks profusely. Several sewage lines drain into the river the water quality has dropped, many aquatic species of the river extinct.

The Historic Elphinstone Bridge is now used for illegal activties during the night. Defecation and suicide attempts are common during the day.Alcoholism takes place during the night since the bridge has no lighting.

The Greenways Junction is the most critical intersection as it receives vehicles from various regions of North and South Chennai. Absense of traffic signal & crossovers makes it difficult for the public.

The four way junction surrounding the Muthulakshmi Park becomes a highly congested intersection during the peak hours. Pedestrian crossing becomes tedious as there are no proper crossovers.

The infrastructure present in the site is not used and maintained. Street lights do not work at interior streets of the slum, which is the cause of illegal activities.

The banks on Sathya Nagar being occupied by the slums and spoiled by the solid waste. Heaps of waste have been created on the banks and water level has gonedown.

The Andhra Mahila Bus Stop near Shivaji Ganesan Memorial has no proper bus bay and shelter. Along the pedestrian path, water stagnates because of improper manholes and drain lines.

Due to the litoral drift alongside the shore, the estuary mouth seems to be closed almost all the time. These mudflats hinder the connection between the river and the ocean.

Ecology - Issues & Policy Interventions

1.Poor Water Quality - Adyar river, after entering city limits, passes through thickly populated areas for about 12.5 kms before its confluence with the sea. the river starts receiving industrial effluents, primarily from tanneries located near pammal. downstream nandanbakkam, the river recieves significant municipal waste waters that primarily form the flow in the channel during the dry period. From nandambakkam to kotturpuram, a number of surface drains as well as overflow severs from waste water pumping stations discharge into the river.

3.Poor Water Containing Capacity - Adyar river has poor water containing capacity because of the frequent sediment formation on the course of the river & the mudflat formation at the Estuary mouth. Due to the litoral drift alongside the shore, the estuary mouth seems to be closed almost all the time. These mudflats hinder the connection between the river and the ocean. These mudflats not only deteriorate the quality of water by stagnating it but also prevent the flood water to enter into the sea which rather floods the settlement.

For tannery waste, new industrial effluent treating plants such as CETP should be installed. These plants can treat 85% of the total effluents. Remaining waste can be dried and disposed of as solids in a secured landfill.To avoid public defecation common toilets should be constructed. to avoid the household wastes and solid wastes from commercial sectors, necessary action should be taken.

2.Island Near Estuarine Region - The islands at the estuarine region were rich in nutrient contents, and ideal to grow mangroves. the island right now contains prosopis sp, which is not allowing any other native trees to grow. Immediate removal of prosopis is not possible because avian fauna has nest on it, so gradual plantation of native trees and removal of prosopis should happen.

Mud Flat Formation

To avoid the consequence of these mudflats, at the estuary point, initially, the mudflat should be completely removed and a 300 metres groyne should be installed. These groynes will prevent the frequent formation of the mudflat at the estuary region. In the case of sediment formation, initially, the sediments have to be removed and dumping of debris should be avoided and monitored.

4.Flood Carrying capacity - The design flood carrying capacity of the estuarine stretch is 1397 cumecs. This is derived considering a design width of 200m, design depth of 3.25 m and design velocity of 213m/s.The mud flats near the mouth reduce the speed of the flood water entering the ocean. this makes flood water entering into the settlement.hence the mudflats need to be removed. if we remove the mud flat the additional advantage is that the impure river water can be diluted.

Amble path - Ecological Intervention

The Amble path is an attempt to interweave the connect within the ecosystem web and connect public to nature. The word Amble refers to “Meander” just like the flow of a river or “taking a stroll” along the river. The first challenge is to identify the species that are suitable for existing in this habitat.

Transit proposal

The Andhra Mahila Bus Stop near Shivaji Ganesan Memorial has no proper bus bay and shelter. Since the road gets narrower from the Thiru-vi-ka bridge, most of the Vehicles use the bus bay to ease their way. The pedestrian path along the edge is not under proper condition and water stagnates because of improper manholes and drain lines.

Riverfront Development

The riverfront along Adyar river consists of various activities that are program-based.The promenade allows the users to interact with water, such as open classrooms for students, riverwalk that educate common people about the importance of river restoration. It enables to natural conditions, native ecology, and a more dynamic relationship between people & river.

Streetscape

Durgabai Deshmukh road, the primary road network within the study area was narrow and not pedestrian-friendly. The intervention is to clear the encroachments, widen the road and introduce pedestrian and cycling lanes. The intersections at the north and south ends of the road are provided with crossing and signals. Street furniture, drinking water fountains, Dustbins & Cycle stands were also provided.

Chennai House Adyar, Chennai

The site was located amidst the dense urban fabric of Chennai, adjacent to a non-perennial river, Adyar. The house was centred in the “almost an acre” sized plot [xxxx sqft]. The rectilinear rooms are lined around a huge courtyard which also contains a well. The entire garden portion around the house will be covered with lush green tropical vegetation. Also, the house was planned to have a water garden on its terrace.

Precast Roof Plan

Hollowcoreslabs, Upturn beams and skylights

Electrical Mockup Fixtures, switchboards & conduits

1:1 Scale model of electrical fixtures, distribution boards switchboards & conduits were made to get a better understanding of the electrical network and to experience the final outcome of the space. Several iterations were worked out based on the scale models to make the electrical system more functional, feasible, proportionate and Aesthetical.

Fan hook

Custom made for Precast hollowcore slab

For mounting the fans, conventional fan hooks cannot be used since the roofing system is a precast hollowcore slab roofing system. Hence a customised fan hook was designed and fabricated which can be utilised in the precast hollowcore slabs. To cover the longitudinal holes in the slabs corrugate GI sheets are used.

Precast roof

Hollowcore slabs, Upturn beams & Skylight parapets

The roof for the entire main house is a precast roofing system, predominantly Hollowcore slabs (HCS). Precast solid slabs are used at the places where the skylights have to be provided. Again the skylight parapets are precast concrete walls. The joints between precast roofing elements are sufficiently waterproofed to accommodate the water garden above.

Precast Roofing Elements