Conservation of Wetlands and Mangroves in Thane Creek and

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1 Sengupta, M. and Dalwani, R. (Editors). 2008 Proceedings of Taal2007: The 12th World Lake Conference: 1635-1642 Conservation of Wetlands and Mangroves in Thane Creek and Ulhas River Estuary, India Vinay S. Nikam1, Arun Kumar2, Kamal Lalla3 and Kapil Gupta 4 1 Indian Institute of Technology Bombay 2 Alternate Hydro Energy Centre , Indian Institute of Technology Roorkee, Roorkee-247667 3 Thane Municipal Corporation, Thane 400601 4 Department of Civil Engineering, Indian Institute of Technology Bombay 400076 ABSTRACT There has been a steady decrease in the area occupied by wetlands in Creeks and Estuaries adjacent urban areas due to unprecedented urban growth in coastal cities, for example Thane Creek and Ulhas River Estuary near Mumbai, India. Urban cities serve as centres of employment and attract a large number of migrants from other places. In case of coastal cities, due to inadequate infrastructure, wastewater and solid waste is disposed into wetlands and Estuary. Discharge of sediments and solid waste into the Creeks from drains and construction activities have resulted in decreased current velocity and depth in the coastal waters of Thane Creek and Ulhas River Estuary. Various researchers have studied individual elements of Thane Creek and Ulhas River Estuary at micro level. However a holistic approach for restoration and conservation of the Creek and Estuary is required. This paper presents the details of an integrated approach incorporating different conservation measures such as sewerage and sewage treatment, urban drainage management, solid waste management, mangrove plantation and dredging. Keywords: Wetlands, Estuary, Conservation plan, Integrated approach. INTRODUCTION with participatory management required for restoration and conservation of the Creek and Thane Creek [Lat. 19000 to 19015 N and Long. Estuary is described in this study. 7205500E to 73000E ] and Ulhas River Estuary [Lat. 18045 to 19000 N and Long. 7204500E to Quality Issues Related to Thane Creek and Ulhas 73020E ] located adjacent to the cities of Mumbai River Estuary and Thane in the state of Maharashtra, India are connected through a narrow and shallow channel. There has been gradual decrease in the amount of Thane Creek is amongst largest marine bodies in an D.O. in Thane Creek since 1981 as shown in Table 1. enclosed area in India. It separates Mumbai and part The depth profile of Hg and Ni clearly shows of Thane city from the main land of India. There is evidence of continuous inputs of Hg and Ni an excessive demand for space in the island to (Jha,1999). Increase in Pb and Hg in the surfacial accommodate increased population resulting in sediments of Ulhas Estuary and bioaccumulation of destruction of mangroves through reclamation of Fe, Zn and Pb in polychates was more in Thane wetlands. Creek as compared to Mahim and Versova Creek Recent water quality analysis of the Thane (Zingde ,1999). Creek and Ulhas River Estuary has shown increasing The monthly fish catch from Thane Creek evidence of pollution due to anthropogenic showed 68 percent reduction in 1992-93 compared to discharges from the surrounding areas. It has been 1981-82, whereas in 1999-2000 it has become an identified that the creek stretch between Balkum to occasional activity of 4 percent compared to 1981-82 Vitawa has become a dead zone (Thane Municipal (Goldin, 2003). Corporation, 2006). The various contributing sources Loss in wetland area in Thane Creek of pollution has been identified in the study are surrounding Digha and Mankhurd is estimated as shown in Fig. 1. 103.2 ha and 343.18 ha, respectively after 1990. Earlier studies for example, Jha, et al.(1999), (Samant,2002 ). In 1981-82 mangroves occupied an Zingde (1999) and Samant (2002) examined Thane area of about 25 ha which reduced to 15ha in 1992- Creek and Ulhas River Estuary at micro level. 93 and to 9 ha in 1999-2000 ( Goldin, 2003). However, these studies have addressed individual aspects. An integrated catchment based approach

2 Ulhas River Et Mira Bhayandar Kalyan Thane Thane Creek Navi Mumbai Mumbai Figure 1. Location of Thane, Ulhas River and Thane Creek. Table 1. Dissolved Oxygen levels of Thane Creek since 1981 Parameter 1981 1989 91-923 Sept 2001- Aug 02 Nov 2001 2005 (Zingde, 1981) (Sahu, 1991) Vitawa area (Athalye, 2003) (Athalye, 2003) (Nikam, (Mishra, 1994 ) 2006) D.O. Surface-4.64 1.98-4.56 0.9-2.2 0.68-5.0 1.17 0 1.80 (mg/l) Bottom- 4.89 (2.05) Figure 2. Water sample location. Figure 3. Sediment sample location. 1636

3 The Thane Creek has very low assimilating capacity of the samples collected from the center of the Creek and wastewater disposed through the primary between Balkum to Kalwa bridge, Kalwa bridge to treatment units and nalla is not getting flushed totally Airoli bridge and Airoli bridge to Vashi bridge are (NEERI 2002). Reduction in effective waterway 0.9 mg/l, 2.2 mg/l and 3.1 mg/l, respectively. This below is observed during the survey conducted in shows deterioration of water quality in the inner 2005. It is also observed that at the confluence of portion of the Creek. Samples collected from Vashi Thane Creek and Ulhas River, the basin of the Thane bridge to Belapur meets the standards as depicted in Creek is constricted. Also, the geometry is such that Fig.4, and this possibly due to good flushing water from Thane Creek is not discharging capacity. Fig. 5 shows that all water samples efficiently into Ulhas River during low tides. collected from the Thane Creek edge does not meet the standard. Present Study DO values for Ulhas River are depicted in Fig.6. Samples collected from the Kalyan area has In the present study, water and sediment quality of DO less than the prescribes standards of 4 mg/l (SW both water bodies have been studied during 8th to 16th II) during low tide. The samples collected from November 2006. A total of 120 water samples and 44 Dombivali to Vasai bassein marginally satisfy the sediment samples were collected from Thane Creek standards. Samples collected along the edge of the and Ulhas River Estuary as shown in Fig. 2 and Fig. Estuary do not meet the standard. 3 respectively Biochemical oxygen demand (BOD) Water quality BOD is the indicator of biodegradable pollution. Physico-chemical properties of Thane Creek and BOD values for Thane Creek center and Ulhas River Ulhas River Estuary have been summarised in Table Estuary are depicted in Fig. 4 and Fig. 6 respectively. 2. BOD values indicate that inner portion of both water bodies are heavily polluted with the BOD values Dissolved Oxygen (DO) exceeding the standard of 3 mg/l (SW II) in almost 100 percent samples collected from edge and center. Poor water quality has been observed in the inner portion of the Creek upto Airoli bridge. Fig. 4 shows Sediment Study all samples collected from the middle of the Creek from Vashi bridge to Balkum has DO values less In present study 33 sediments samples from Thane than the prescribes standards of 4 mg/l (SW II ) by Creek and 10 from Ulhas River Estuary were Central Pollution Control Board. Average DO values collected. Table 2. Physico-chemical properties of Thane Creek and Ulhas River Estuary water Parameter Thane Creek Ulhas River Estuary Balkum to Kalwa bridge to Airoli bridge to Vashi Bridge to Balkum to Kalyan to Kalwa bridge Airoli bridge Vashi bridge Belapur Vasai Balkum pH 7.1-7.9 7.1-7.8 7.1-7.4 7.3-7.6 6.2-7.8 7.4 8.0 (7.5) (7.5) (7.2) (7.0) (7.73) DO (mg/l) 0-1.8 0-3.6 1-4.8 3.2-6.0 3.8-5.8 3.4 4.6 (0.9) (2.2) (3.1) (5.1) (5.1) ( 4.03 ) BOD 3.6-6.0 3-5.4 3-5.6 4.8-7.0 3-12 7.3413.36 (mg/l) (4.8) (4.1) (4.1) (5.5) (5.1) (9.61) NO3-N (mg/l) 0.4-0.8 0.33-0.83 0.19-0.53 0.48-0.72 0.162-0.901 (0.57) (0.5) (0.3) (0.7) (0.414) PO4-N (mg/l) 0.213-0.483 0.132-0.482 0.041-0.862 0.158-0.304 0.025-0.126 (0.377) (0.2) (0.2) (0.2) (0.070) Suspended 20-50 20-50 10-40 10-40 Solids (mg/l) (30.8) (30.0) (22.3) (21.7) 1637

4 ppm 1638 ppm 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 Diwalya Bridge South of seawoods Nalla I Seawoods II At Seawoods Near INS Chanakya. Karave .+7km Vashi bride to panvel .+ 5km Vashi bride to panvel DO DO .2km Vashi bride to panvel Near Vashi bridge .+1.5km Vashi bridge to airoli Figure 4. DO and BOD levels at Thane Creek center Ghatkopar Vikhroli 1 DO lower limit DO lower limit Koparkhairane Location Location Vikhroli nala 2 Bhandup Talawali rabodi midc Figure 5. DO and BOD levels at the Thane Creek edge (Vashi to Balkum) Airoli creek BOD upper limit BOD upper limit Airoli powerhouse Creek Digha creek Indal Mukund creek BOD BOD Kalwa bridge creek Manisha nagar creek Saket creek Balkum creek

5 16 14 12 10 ppm 8 6 4 2 0 Location DO mg/l BOD mg/l DO low er limit mg/l BOD upper limit mg/l Figure 6. DO and BOD at the center of Ulhas river estuary 24 Organic content, percent 22 20 18 16 14 12 10 Sampling station Figure 7. Organic content present in Sediments of Thane Creek Organic Content Wagbil. High organic content was observed in sediment samples collected from Wagbil and Kolshet Organic content present in the sediments of Thane nalla at the edge of Ulhas River Estuary. Creek and Ulhas River Estuary is show in Fig. 7 and Fig. 8, respectively. The portion between Balkum to Nitrates and Phosphates Airoli high organic content is observed as compared to rest of the part of Thane Creek reflect the impact Nitrates and Phosphates present in sediments of domestic sewage disposal. In Ulhas River Estuary Thane Creek and Ulhas River Estuary are shown in high organic content are observed from Kolshet to Fig. 9 and Fig. 10, respectively. High nitrates values 1639

6 are observed from Bhandup to Ghatkopar for Thane higher phosphates values as compared to the rest of Creek and Bhayandar and Kolshet area for Ulhas the samples collected from Thane Creek. River Estuary, which are prone to the disposal of domestic waste. Heavy Metals High phosphates levels in sediments are observed at Ghatkopar, Vashi and area between Heavy metals viz: zinc, chromium , cadmium and Kalwa bridge to Balkum for Thane Creek. Sediment copper content are traced in following location collected from Rabodi nalla Creek edge has shown 30 28 26 24 Organic content, percent 22 20 18 16 14 12 10 Kolshet Ghodbunder Airforce Versova Bhayandar Bhayandar Waghbi Miraroad Miraroad Miraroad nalla 1 nalla 2 station nalla 2 nalla 3 Nalla nalla nala1 nalla 1 nalla 2 nalla Sampling station Figure 8. Organic content present in Sediments of Ulhas River Estuary 0.4 0.35 0.3 0.25 gm/kg 0.2 0.15 0.1 0.05 0 Indal Mukund Seawoods Rabodi Nalla Rabodi Nalla Juigaon Nalla Chembur Bhandup Vashi Gaon Ghansoli Balkum Nalla Meghale Vitawa nalla Mhada Wagbil nalla Vikroli Nalla Vikroli Nalla Nerul Nalla Karawe Manishanagar Behind ST Airoli power Saket Nalla Airoli nalla Airoli Nalla Koparkhairne Talawali - Ghatkopar Nalla from Custom Kopari STP Opposite Thane Digha nalla Sampling station Nitrate (gm/Kg) Phosphate (gm/Kg) Figure 9. Nitrates and phosphates present in sediments of Thane creek Thane Creek edge Saket, Rabodi, Manishanagar, Meghale, Custom office nalla, Kopari STP outlet , Indal Mukund nalla, Mhada colony nalla , Nerul nalla, Karawe nalla, Seawoods nalla and near Uran bridge Ulhas River Estuary edge Airforce station nalla, Wagbil nalla, Miraroad nalla, Bhayandar nalla 1640

7 0.2 0.18 0.16 0.14 0.12 gm/Kg 0.1 0.08 0.06 0.04 0.02 0 Kolshet Ghodbunder Airforce Versova Bhayandar Bhayandar Waghbi Miraroad Miraroad Miraroad nalla 1 nalla 2 station nalla 2 nalla 3 Nalla nalla nala1 nalla 1 nalla 2 nalla Sampling station Nitrate (gm/Kg) Phosphate (gm/Kg) Figure 10. Nitrates and phosphates present in sediments of Ulhas river estuary ACTIONS PROPOSED Kopari and augmentation of its 120 Mld ii) capacity from 54 MLD (existing) A holistic approach is required while planning the to 120 MLD mitigation measures to conserve mangroves and iii) New STP at Kharegaon 100 Mld wetland. Thane Creek and Ulhas River Estuary is to iv) New STP for Mumbra Kausa area 25 Mld consider as whole while planning the mitigation v) New STP for northern part along Ghodbunder measures. Various organisations are in charge of road 40 Mld Total 294 Mld areas adjacent to both water bodies namely, Municipal Corporation of Grater Mumbai, Thane Solid Waste Management Municipal Corporation, Navi Mumbai Municipal Corporation, Kalyan Dombivali Municipal Measures are taken to prevent the disposal of solid Corporation, Ulhasnagar Municipal Corporation, waste along the banks of water bodies. TMC has Mira Bhayandar Municipal Corporation, City and acquired a land at Diaghar scientific land fill site. Industrial Development Corporation Maharashtra TMC has proposed to install and operate four waste Maritime Board (MMB), State Government, Ministry EPS and waste plastic melting machine through of Environment and Forest, Department of Ocean social organisation. Development. The success of the conservation programme depends upon an integrated operational Mangroves plantation strategy of the various agencies. The various mitigation measures proposed for TMC Mangrove plantation drive is already started by and extent of their implementation is described TMC, under which One lakhs mangroves are likely below. to be planted. Sewerage Scheme Dredging and Basin Canalisation TMC is implementing an Underground Sewerage It is necessary to increase the flushing capacity of the Network and Treatment Project of amounting Creek, which can be done by dredging the basin in Rs.427.93 Crores under Jawaharlal Nehru National proper manner. Area under the bridge is proposed to Urban Renewal Mission (JNNURM) of Government clean to increase waterway. of India, to conserve Thane Creek and Ulhas River Estuary. Project components are: laying of sewer Rainwater Harvesting lines, installation of pumping stations, upgradation of existing STP and construction of new decentralised TMC has made mandatory to all new construction STPs, and low cost sanitation system. The sewage projects to implement rain water harvesting, which treatment plants are designed taking into will reduce the runoff quantity. consideration of the assimilative capacity of the Thane Creek and Ulhas River Estuary. Four sewage Public Participation and Awareness treatment plants of total capacity 290 Mld are proposed as under: For successful implementation of conservation i) Up gradation of existing STP at program it is necessary to involve public at various 1641

8 stages viz planning, implementation and post Jha, S.K, Krishnamurthi,T.M., Pandit, G.G. and Nambai, implementation stage. Awareness program acts as a K.S.V., (1999). History of Accumulation of Mercury catalyst, which trigger the sentiments of the citizens and Nickel in Thane Creek, Mumbai, Using 210 Pb towards the Creek and Estuary. TMC is regularly Dating Technique. The Science of Total Environment, 236;91-99. conducting awareness programs on various occasion Mishra,V., Goldin, Q., Ullal, Q.V., Gokhale, K.S., and such World Water Day, Environmental Day, etc. Athalye, R.P., (1994). Sea Anemone, Accotiactis Gokhaleae as Biofouler in the Mangrove Mudflats CONCLUSIONS along Thane Creek. Mahasagar-Bulletin of National Institute of Oceanography, 27(1): 73-78. This paper has presented the current status of NEERI, (2002). Determination of Assimilative Capacity of pollution in Thane Creek and Ulhas River Estuary. Thane Creek. The measures being undertaken by Thane Municipal Nikam, V.S.,(2006). Conservation of Thane Creek and Corporation have also been presented. A thorough Ulhas River Estuary. M.Tech Thesis, Indian Institute of Technology, Roorkee. understanding of the ecosystem and integrated Samant, H.P., (2002). Quantifying Mangrove Cover approach towards planning, utilization and Change in and around Mumbai using Satellite Data. management of resources, participation of various Proceedings of the National Seminar on Creeks, stakeholders with an integrated efforts is needed to Estuaries and Mangroves - Pollution and conserve the wetlands and mangroves of Thane Conservation, 28th to 30th November, Thane, pp Creek and Ulhas River Estuary. 334-337. Sahu, K.C. and Bhosale,U., (1991). Heavy Metal Pollution REFERENCES Around the Island City of Bombay, India. Part II: Quantification of Heavy Metal Pollution of aquatic Sediments and Recognition of Environmental Athalye, R.P., Patil, N.N., Borkar, M.U., Quadros, G., and Discriminants. Chemical Geology, 90:263-283. Somani V.U: (2003). Studies of Flora, Intertidal Thane Municipal Corporation, (2006). Report on Macrobenthic Fauna and Fishery of Ulhas River and conservation of Thane Creek and Ulhas River Thane Creek to assess the pollution status and decide Estuary. mitigation strategy. B.N. Bandodkar college of Zingde, M.D. and Desai. B.N., (1981) .Mercury in Thane Science Project report submitted to Mumbai Creek , Bombay Harbour. Marine Pollution Bulletin, Metropolitan Region Environment Improvement 12 (7): 237-241. Society, Maharashtra Metropolitan Development Zingde, M.D., (1999). Marine pollution- Where are we Authority, Mumbai. Heading For? IN: Somayajalu, Blk (Ed) Ocean Goldin, Q., (2003). Determination of Thane Creek Science Trends and Future Direction. Indian National Ecosystem near Thane City Over Past 20 Years. Science Academy, New Delhi, 294-246. Sesheiyana, 2:6-7. 1642

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