Proceedings of an International Symposium 18 May 2012 , Peradeniya, Sri Lanka

URBAN LAKE MONITORING AND MANAGEMENT

Editors S. Pathmarajah K.B.S.N.Jinadasa M.I.M. Mowjood

URBAN LAKE MONITORING AND MANAGEMENT

PROCEEDINGS OF AN INTERNATIONAL SYMPOSIUM

Editors S. Pathmarajah K. S. B. N. Jinadasa M.I.M. Mowjood

Assistant Editor K.P.D.C.H. Kaushalya

Sponsors Cap-Net Lanka Postgraduate Institute of Agriculture (PGIA), Peradeniya University of Peradeniya & AA Science Platform Program on ‘Development of bio-engineering by vegetation and for wetlands as a solution of environmental and natural disaster problems for expanding urban fringe zone in Asia’, Japan Society for the Promotion ofScience (JSPS)

Publisher Cap-Net Lanka Department of Agricultural Engineering Faculty of Agriculture, University of Peradeniya Sri Lanka, 2012 Urban lake monitoring and management: Proceedings of aninternational symposium, 18 May 2008, Peradeniya, Sri Lanka.

Editors:

S. Pathmarajah, B. Sc. Agric. (Sri Lanka), M.Phil. Agric. (Sri Lanka), D. Tech. Sc. (AIT) [email protected]

K. S. B. N. Jinadasa , B. Sc. Eng. (Sri Lanka), M. Sc. Eng., Ph. D. (Saitama) [email protected]

M.I.M. Mowjood, B. Sc. Agric. (Sri Lanka), M. Sc. Agric., Ph.D. (Iwata) [email protected]

Assistant Editor: K.P.D.C.H. Kaushalya, B.Sc. Agric., M.Sc. NRM (Sri Lanka) [email protected]

University of Peradeniya Peradeniya, Sri Lanka

Panel of reviewers:

E.R.N. Gunawardena, Prof ., B. Sc. Agric. (Sri Lanka), Ph.D. (Silso) S. Pathmarajah, B. Sc. Agric. (Sri Lanka), M. Phil (Sri Lanka), Ph.D. (AIT) M.I.M. Mowjood, B. Sc. Agric. (Sri Lanka), M. Sc. Agric., Ph.D. (Iwata) L. W. Galagedara, B. Sc. Agric. (Sri Lanka), M. Sc. (Japan), Ph. D. (Canada) N.D.K. Dayawansa, (Ms.), B. Sc. Agric. (Sri Lanka), M. Sc. (AIT), Ph.D. (Newcastle)

© 2012 Cap-Net Lanka Department of Agricultural Engineering Faculty of Agriculture University of Peradeniya Peradeniya, Sri Lanka Responsibility of the contents of the papers in this proceedings rest with authors.

ISBN 978-955-0597-01-7

Preface

Despite the small and shallow nature of urban lakes, they play a vital role in urban landscape, ecosystem and the environment. They often play a role in recreation, water supply, flood control and other direct and indirect human uses. The quality and quantity of water reaching the urban lakes are strongly influenced by watershed utilization associated with rapid urbanisation. Since urban watersheds could produce higher nutrient and heavy metal loads from runoff due to contributions from municipal wastewater discharges and sewage overflows compared to other watersheds, urban lakes become more polluted than non-urban lakes. In addition, internal sources like bird and fish droppings, sediment release, etc. also could contribute to nutrient load. Because of the shallow nature and nutrient richness, urban lakes tend to be dominated by aquatic weeds. The studies tracking the changes in urban lake water quality as a function of watershed development are found in isolation and needs to be compiled to understand the dynamics. Cap-Net Lanka– the local arm of the Global Capacity building Network in Integrated Water Resources Management (IWRM) is mandated to impart new knowledge and disseminate the knowledge generated by the local institutions and individuals in the field of IWRM in Sri Lanka. As such, this symposium is organised to provide a common forum to the students, researchers, managers, administrators, and policy makers in Sri Lanka to share the current knowledge on urban lakes related issues and learn from the experience of the scientists from the other countries. On behalf of the Cap-Net Lanka, I extend my gratitude to the Postgraduate Institute of Agriculture (PGIA), Peradeniya, University of Peradeniyaand the Japanese Society for the Promotion of Science (JSPS) for co-sponsoring the symposium. We are thankful to the visiting scientists from Japan, Singapore and India for accepting our invitation to attend this symposium and making their invaluable contributions. I also extend my sincere gratitude to all the invited guests, presenters and the audience without whom this event wouldn't have been a success. I appreciate the service rendered by the reviewers who helped to improve the quality of thisproceedingsimmensely. The support extended by the academic and academic-support staff members and the students of the University and the PGIA are greatly appreciated. My special thanks go to Ms. Lakmali Chathurika, Ms. S.H. Madushani Dahanayake, Mr. Nuwan Wijewardana and Mr. K.P.D.C.H. Kaushalya for the Administrative and Technical support rendered.

S. Pathmarajah Symposium Coordinator / Editor

iii

Message from the Coordinator of JSPS Science Platform Program

The JSPS AA Science Platform Program is designed to create high potential research hubs in selected fields within the Asian and African regions, while fostering the next generation of leading researchers. The three-year program proposed by SaitamaUniversitycollaborating with three Sri Lankan universities (Univ. of Moratuwa, Univ. of Peradeniya andUniv. of Ruhuna) has been selected as one of the promising distinguished programs by the Japan Society for the Promotion of Science (JSPS). Exchanges will be conducted under the leadership of the core institution (SaitamaUniversity) and joint research, seminars and other scientific meetings, and researcher exchanges will be organized and carried out effectively under the program. It is also anticipated that the hubs formed by the core institutions will continue to carry out important research activities after funding for the project has ended. I am happy to deliver this message at the occasion of this International Symposium on Urban Lake Monitoring and Management in which JSPS AA Science Platform Program is also a partner. I hope the symposiumwill provide an excellent opportunity to establish fruitful international collaboration between the above-mentioned universities. I would like to thank Dr. S. Pathmarajah, Dr. S. Jinadasa and Dr. M.I.M. Mowjood from University of Peradeniya for their efforts in organizing this symposium.

Norio Tanaka Coordinator of JSPS AA Science Platform Program on ‘Development of bio-engineering by vegetation and for wetlands as a solution ofenvironmental and natural disaster problems for expanding urban fringe zone inAsia’ Institute for Environmental Science and Technology, Graduate School of Science and Engineering, Professor at Saitama University, Japan

TABLE OF CONTENTS

Volume I

Impact on Etroplus suratensis (pisces: Cichlidae ) population attributed to human induced hydrological modifications to the Koggala lagoon, Sri Lanka . G.P.Amarasekara1, Tilak Priyadarshana, Jagath Manatunge, and Norio Tanaka 1

Possible solutions mitigating pollution at Kandy lake, Sri Lanka. K.B.S.N.Jinadasa, C.S.Kalpage, G.B.B.Herath1. C Devendra, W.J. Ng, S.K. Tan 11

Algal bloom and lake water quality: a case study of toxin producing cyanobacteria, ( Cylindrospermopsis racibroskii ) in Nuwarawewa, Anuradhapura. J. K. Ariyawansa, M.I.M. Mowjood, and E.I.L. Silva 15

Mixing states of Koggala lagoon in dry season. E. Furusato, G. P. Amarasekara, S. Yasuda, T. Priyadarshana and N. Tanaka 25

First field experience on application of floating wetland in urban lake water restoration in Sri Lanka. S.K.Weragoda, K.S.B.N. Jinadasa and Ng Wun Jern 35

Volume II

A strategic framework for an integrated water management and water supply chain for an urban centre: watersheds, reservoirs, and water supply network – security & risk. Prof. Tan Soon Keat 49

Sustainable management of urban lakes environment and ecosystem: a case study on lakes of Udaipur. Sonal Gupta 57

Integrated lentic and lotic basinmanagement (IL 2BM) forurban lakes: water governance for sustainability and livelihood of people. Sandeep Joshi 67

Seasonal variation of water quality and plankton of lake Gregory, Sri Lanka. M. B. U. Perera, S. K. Yatigammana, S. A. Kulasooriya , N.P. Athukorala 75

Why proactive water management is important for urban lakes? The case of Kandy lake. Silva, E.I.L and Herath Manthritilake 87

Urban lakes as multiple use systems: need for coordination among stakeholders and institutional arrangements. R Dalwani 97

Restoration of the riparian zone of lake Richmond through landcare. Kamal Melvani and S. Pathmarajah 107

Urban lakes in stormwater management of an urban centre. Xiaohua WEI, Dongqing ZHANG and Soon Keat TAN 119

Nutrient removal in tropical subsurface flow constructed wetlands. Dong Qing Zhanga, Junfei Zhua, Yifei Lia, Richard M. Gersbergc, Soon Keat Tanb 127

Determination of the current status of water quality in some economically important water bodies in Sri Lanka. Azmy S.A.M., Weerasekara K.A.W.S., Hettige N.D., Wickramaratne C. and Amaratunga A.A.D. 135

Assessment of causes for frequent occurrences of fish kill incidents of Sri Lanka with special reference to water quality. Weerasekara, K.A.W.S., Azmy S.A.M., Hettige, N.D., Wickramarathne, C., Amarathunga A.A.D., Heenatigala P.P.M. and Rajapakshe, W. 145

Agriculture and water pollution: a study in catchment of lake Gregory and agricultural areas in Nuwara Eliya. H.P. Henegama, N.D.K. Dayawansa, Saliya De Silva 153

Assessment of the effects of surface water pollution on reduction of land value using GIS; a case study of the hamilton canal in Wattala D.S. Division. W.D.K.V. Nandasena, H.M.Paba Herath, S.I.S. Subasinghe 165

Volume I

Session of JSPS AA Science Platform

IMPACT ON Etroplus suratensis (PISCES: Cichlidae ) POPULATION ATTRIBUTED TO HUMAN INDUCED HYDROLOGICAL MODIFICATIONS TO THE KOGGALA LAGOON, SRI LANKA

G.P.Amarasekara 1, Tilak Priyadarshana 1, Jagath Manatunge 2, and Norio Tanaka 3 1 Faculty of Fisheries and Marine Sciences & Technology, University of Ruhuna,Sri Lanka. 2 Department of Civil Engineering, Faculty of Engineering, University of Moratuwa,Sri Lanka. 3 Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.

ABSTRACT This study investigated how the groyne constructed at the lagoon mouth of Koggala has been affected the green chromide, Etroplus suratensis, population. The groyne is resposible for increased salinity of the lagoon and enhanced entrance of predators as it has prevented the formation of natural sand bar that makes sea and lagoon seperated from time to time. The effects of salinity on growth and survival of E. suratensis was determined from juvenile state at salinities from 4 to 24 ppt in three separate trials of 12 months duration, respectively. It was found that survival is significantly different (p<0.05) from 255 days of varying salinity. The optimum was found in 16 ppt and lowest found in 24ppt. In Koggala lagoon, E. suratensis took 290 days to mature and spawn. From the tank experiment it was found that more than 80% of the population in 24 ppt salinity was terminated before attending to maturity. Growth rates of E. suratensis in different salinity treatments were significantly different throughout the period of 255 days (p<0.05). Growth rates in 24ppt are lower than those of lower salinities. The marine origin Epinephelus spp act as natural predators of E. suratensis and their migration became high throughout the year due to opening of the lagoon mouth. High salinity and predator density were the main growth controlling factors of E. suratensis. Key words: Etroplus suratensis, hydrological modifications, lagoon

1.0 INTRODUCTION Coastal wetlands including lagoons are increasingly subjected to anthropogenic activities that are driven by economic and developmental needs. Such activities may shift natural hydrological regime that lagoon has adapted for many years, consequently making a huge impact on wellbeing of all life forms (Gunawickrama & Chandana, 2006). Several natural and anthropogenic factors may have a direct influence on the environment and on food resources, distribution, growth, and survival of lagoon fish (Perez-Ruzafa et al, 1991). Salinity is the most prominent single factor that affects biota of lagoon. Therefore, the salinity regime change was studied with respect to the growth and distribution of Etroplus suratensis .

Koggala lagoon is located (5º 59' - 6º 02' N and 80º 18' - 80º 21' E) on the southern coast of Sri Lanka (Figure 1). The total extent of the lagoon is around 640 ha. Its depth ranges from 1 to 4.2 m.

Figure 1: Map of Koggala Lagoon showing sampling stations. Suburb

marsh & paddy field areas are shown in different shaded patterns.

The lagoon is bordered by narrow fringe of mangrove and marsh or paddy lands beyond which a small and undulating catchment area of 60 km 2. The lagoon is a freshwater and estuarine complex which receives freshwater from several canals that enter the lagoon from the northern end. The only sea outlet is located at the south-eastern corner. It has been often blocked by a natural sand bar that prevents free tidal movements of water and sea water intrusion into the lagoon. The sand bar was breached during the rainy season to prevent flooding the hinterlands. After the natural sand barrier at the outlet was removed for some development activity, a groyne system was built to minimize coastal erosion. However, since then, due to the construction of the groyne at the lagoon mouth, the mouth has been kept open throughout the year. Strong sea water inﬂuence seem to have felt by the lagoon as far as about 2 km from the lagoon outlet. That has caused a lot of problems in the lagoon environment making high saline condition. That situation has caused concern with resource users and environmentalist since the lagoon’s hydrology, salinity and thus ecology has changed dramatically. The lagoon is known to harbor a diverse fauna as reported previously (CEA. 1999) and thus has a high ecological signiﬁcance. Due to high saline condition, the natural vegetation, in particular the fringing belt of mangroves

2 and the natural faunal collection have to face disappearance in large extent or severe affection. Salinity is found to be the most important abiotic factor affecting fish biomass (Marshall and Elliott, 1998) and only second to temperature that has an important impact on fish biomass distribution. Etroplus suratensis (bloch) is an indigenous cichlid fish restricted in distribution to Sri Lanka and India (Ward & Wyman, 1977). The fish is adjusted to euryhaline, commonly occurring in riverine estuaries and coastal lagoons. Fishermen engaged in Koggala lagoon have noted markedly decreasing catches of E. suratensis after construction of the groyne system. Although it is well known that E. suratensis are capable of tolerating a wide range of salinities, the optimal salinity for maximizing growth and survival has not yet been determined.Salinity only is a known determinant of distribution and habitat for several fish species (Augley et al., 2007). In most species, egg fertilization and incubation, yolk sac resorption, early embryogenesis, swim bladder inflation and larval growth are dependent on salinity. In larger fish, salinity is also a key factor in controlling their growth (Bouef and Payan, 2001). Fish population density and assemblages are also potentially affected by predator species.

2.0 METHOD 2.1 Analysis of effects of salinity on growth of E. suratensis The adult fishes Etroplus suratensis were collected as wild from the Koggala lagoon, Sri Lanka by cast net operation during the early mornings. The collected breeders were disinfected by dipping in 1% commercial formalin and acclimatized before introducing into fibre glass tanks containing filtered well- aerated estuarine water. As sex determination was difficult the sex ratio had to be assumed as 50:50. Materials like coconut leaf petioles, coconut husks, and bricks were provided as spawning surfaces for egg attachment. The fishes were maintained at constant salinity, (15.0±0.2ppt) and temperature (29.0±2.4 °C) according to Abraham, 1995. Feeding of the breeders was initiated in three days after stocking with artificial feed prepared as described by CIBA, 1995. The feed consisted of groundnut oil cake 40%, rice bran 45% and fish meal 15%, fortified with vitamin and mineral mix at 25 grams per 1kilogram of feed in pelleted form was provided. After spawning, a suitable group of juvenile individuals of same parents and same aged were selected and they were maintained at the same salinity for one month. Fish were selected randomly from the selected group. Then they were acclimated to the four salinity regimes (4‰, 8‰, 16‰ and 24‰±0.2‰) in twelve tanks. (3 tanks per salinity×4 salinities=12tanks).

The desired salinities were obtained by diluting seawater which was taken near the lagoon mouth with freshwater. A number of randomly selected two fish were kept in each tank. The fish initial total length was 1.80±0.50 cm. To identify both fish in each tank, a tiny partial cut was done in the caudal fin. In a pilot study, it is found that there was no significant difference (p>0.05) in growth between fish having tiny partial caudal fin cut and those without such a cut. All tanks were arranged in a random block in parallel rows indoors. In order to prevent the fish swoop, each tank was covered with a mesh on top of the tank. Aeration was provided continuously and one-third of the water volume was exchanged by pre-adjusted seawater once in three days to ensure high water quality. Tanks were aerated by means of compressed air passing through air stones and that maintained the oxygen tension at a constant level. During acclimation and the experiment, the dissolved oxygen level was maintained above 5.0 mg/L, pH at 7.8±0.2, and temperature at 30.0±2.5 °C. Salinity, temperature and dissolved oxygen in each tank were measured at 0800 daily with a YSI-85 digital water quality meter and pH was measured with a pH meter. Natural photoperiod was applied and fish were fed two times daily (8:00, and 18:00) with the same feed that was given to the breeders, until the fish rejected food. As a dietary supplement, leaves of aquatic plants ( Ipomoea aquatica ) were given three times per week. It was done to ensure that growth was not compromised by the possibility of a nutritionally incomplete diet. The uneaten feed and feces were collected by siphon within 2 hours after each meal. Fish total lengths were recorded to the nearest 0.1 cm at the start of the experiment, and these were measured approximately once in every 15 days from 07th of December, 2010 to 10th of December, 2011. Increase in total lengths of ﬁsh within 15 day increments in the salinity treatments were used to analyse their growth performances. Life time of each fish in days was also recorded. 2.2 Analysis gut content of Epinephelus spp . Ten fish of Epinephelus spp were selected randomly from the fish collecting center in Koggala. The body cavity of each ﬁsh was carefully opened and the anterior gut was removed. The content from each anterior gut section was carefully washed into a petri dish. Hand lens was used to identify gut contents. Percentage of occurrence of E.suretensis was calculated. 2.3 Statistical analysis For analysis of effects of salinity on growth of E. suratensis The normality test and Levene’s test for equality of variances were carried out on data sets prior to the statistical analysis, in order to verify the assumption of normal distribution and homogeneity of the variances. Increases in total lengths in 15 day intervals with the initial lengths of fish amongst the four

4 treatments were analysed separately using analysis of variance (ANOVA) followed by pair wise multiple comparisons with Tukey–Kramer’s HSD test procedure. Data columns with missing values were not considered for the calculations. Differences in life time of fish amongst the four treatments were analysed separately using analysis of variance and pair wise comparisons with Tukey– Kramer’s HSD test procedure. A cross tabulation was done by 15day increments considering whether the fish in each salinity treatment was alive or dead. The resultant contingency table was analysed with the Chi-Square test to determine whether salinity affects on survival of the fish. All these procedures were done according to George and Mallery (2007). All statistical analyses were performed at α = 0.05 with SPSS 19.0 (SPSS Inc., Chicago, Illinois) [19].

3.0 RESULTS 3.1 For analysis of effects of salinity on growth of E. suratensis

Although the research was carried out more than one year, growth performances were compared only up to 255 days, because more than 80% of fish in 24 ppt salinity treatments has been died after 255 days (Figure 2).

Figure 2:Growth of E.suratensis in different salinities. Results showed that throughout the period of 255 days, there was a significant difference in growth in different salinity treatments. (P<0.05). Tukey post hoc test showed that growth performances of fish in different salinities were significantly different from each other. But there is no significant pattern in it. When the lifetime of fish was considered, there was a significant difference in life time of fish in different salinity treatments. (ANOVA, F=5.174, df=3, P<0.05). The Tukey post-hoc test showed that life time of fish in salinity treatment 24 ppt was signiﬁcantly different from each other.

Figure 3 shows distribution of life times in each salinity treatment during 345 days. Mean life time of 16 ppt tank is the highest and those in 24 ppt is the lowest, while those in 4 and 8 ppt are nearly same.

Figure 3:Box plot of life times of E. suratensis in different salinities. Lines within the boxesare medians. Boxes indicate interquartile range from q2 –q3.

Cross tabulation and Chi-Square test showed that there was significance in survival of fish in salinity treatments after 255 days. (df=3, χ2 = 10.286, P<0.05). It is observed that E. suratensis takes more than 10 months to mature in the Koggala lagoon. At that time, more than 80% of fish in 24 ppt salinity were died. That means there were only less than 20% of fish in 24 ppt or higher salinities can mature and spawn. Although it is concluded tha t the most suitable salinity for E. suratensis is 16 ppt the mean salinity of the main water body of the lagoon exceeds 24ppt in many months of the year. Salinity of the lagoon varied between 18-28 ppt (Figure 4).

Figure 4: Temporal variations in m ean salinity (±SE) of Koggala lagoon.

3.2Analysis gut content of Epinephelus spp. Body parts of fish including E. suratensis could be identified in the gut contents of Epinephelus spp . proving their carnivorous habit. The frequency of occurrence of E. suratensis in the gut contents was 40%. Epinephelus spp can invade the lagoon throughout the year due to the mouth opening of the Koggala lagoon. The combined effect of high salinity and predators causes a drastic decrease in the E. suratensis population day by day. Therefore, the presence of E. suratensis in the daily fish catch of the lagoon becomes a very rare incident as the groyne has effected badly to the sustainability of the population.

4.0 DISCUSSION Growth rate and survival of E. suratensis were optimum at 16 ppt and decreased at higher salinities. Salinity has been shown to affect growth of fish and higher growth at lower salinities is almost universally accepted as applying to most brackish water fish species (Boeuf and Payan, 2001). The main hypothesis relating salinity to growth suggests that fish living in hypo and hyper-osmotic habitats have additional energy costs associated with osmotic and ionic regulation, and that energy for these costs is met, at least in part, by energy diverted from growth processes to osmoregulation (Lyndon, 1994). Such physiological, rather than behavioural, causes are likely to be the explanation of the results reported here, since feeding behaviour, as indicated by food consumption rates, was not significantly different between salinity treatments. However, activity levels were not controlled for in the current study, so the effect of salinity on activity cannot be assessed. Several physiological factors that help determine growth rates in fish could be affected by salinity. Food intake may be affected by salinity, mediated via different drinking rates in different salinities (Tytler and Blaxter, 1988; Laiz- Carrion et al., 2005). Salinity and temperature can affect feeding efficiency of larvae by influencing processes such as metabolism, oxygen consumption, behaviour and swimming speed, andgut evacuation time (Blaxter, 1988). However, such parameters and habits were not analised within this research. Misra (2003) showed the effect of salinity on fertilization, hatching, and survival of juvenile E. suratensis. In that study, it was proved that when salinity increases from 15 ppt to 25 ppt, percentage of fertilization and hatching eggs decreased and finally survival also decreased. Maximum fertilization, hatching and survival were recorded at 15 ppt. Those results coincide with the results of this study. Another effect of modifications of the Koggala lagoon outlet with the open sea is the colonization by new marine species. The opening of the lagoon mouth throughout the year causesmarine origin Epinephelusspp . to invade lagoon

7 ecosystem more easily from the sea. Several researches also reported that the carnivorous habit of Epinephelus spp . (Barreiros and Santos, 1998). E. suratensis is prone to many diseases mainly caused by wide fluctuations in environmental parameters. High saline condition created stress among fish lived. Stress is a state or condition, caused by intrinsic or extrinsic factors which upsets the adaptive responses of the animals and reduces the chances of their survival. Stress causes severe damage as a result of long-term exposure (Pillai, 1984). In addition to salinity and predators, several other factors such as the influence of tides, velocity, and light intensity in the lagoon can influence fish growth and assemblages. But they could not be fully explained here, as it is difficult to analyse each factor individually as they interact with each other. Gunawickrama (2007) showed that E. suratensis from Koggala lagoon have one of the largest maximum body depth in Sri Lanka. So it is very important to restore the lagoon as early as possible to protect its biodiversity.

5.0 CONCLUSIONS Survival and growth of E. suratensis population in the main water body has decreased due to combined effect of high salinity and high predation throughout the year. The eco-hydrological stability of the Koggala lagoon has been affected due to the construction of groyne.

6.0 REFERENCES Abraham, M. and M. Sultana, 1995. Biology, Fishery, culture and Seed Production of the Pearl spot, Etroplus suratensis (Bloch). Part II. . Methodology of Seed Production. In:CIBA Bulletin No.7, pp.40-45.

Augley, J, Huxham, M, Fernandes, T.F, and A.R. Lyndon, 2007. The effect of salinity on growth and weight loss of juvenile plaice ( Pleuronectes platessa , L): An experimental test, Journal of Sea Research 60 (2008), pp.292-296. Barreiros, J.P and R.S. Santos, 1998 - Notes on the food habits and predatory behaviour of the dusky grouper, Epinephelus marginatus (Lowe, 1834) (Pisces: Serranidae) in the Azores. Arquipelago, 16A : 29-35. Blaxter, J.H.S, 1988. Pattern and variety in development. In: Hoar, W.S., Randall, D.J. (Eds.), Fish Physiology, vol. XI. Academic Press,Inc., London, pp.1– 58 Boeuf , G, and P. Payan, 2001. How should salinity influence fish growth?, Comparative Biochemistry and Physiology Part C 130: 411-423. Central Environmental Authority (CEA), Sri Lanka,1999. Wetland Atlas of Sri Lanka.Wetland Conservation Project- Central Environmental Authority of Sri Lanka/ ARCADIS/ EUROCUNSULT, pp.1-75.

CIBA, 1995. Biology, fishery, culture and seed production of the pearlspot Etroplus suretensis (Bloch). Central Institute of Brackish water Aquaculture of India. Bulletin No 7, pp.10-42. George, D.andP. Mallery, 2007. SPSS for Windows step by step. Tenth edition: Pearson. Gunawickrama, K.B.S, 2007. Morphological heterogeneity and population differentiation in the green chromid Etroplus suratensis (Pisces: Cichlidae) in Sri Lanka. Ruhuna Journal of Science,2. pp.70-81. Gunawickrama, K.B.S. and E.P.S.Chandana, 2006. Some hydrographic aspects of Koggala lagoon with preliminary results on distribution of the marine bivalve Saccostrea forskalli : pre tsunami status. Ruhuna Journal of Science, Vol1, pp.16- 23. Lyndon, A.R, 1994. A method for measuring oxygen-consumption in isolated-perfused gills. Journal of Fish Biology 44, pp. 707–715. Marshall, S, and M. Elliott, 1998. Environmental influences on the fish assemblage of the Humber estuary, UK. Estuarine Coastal and Shelf Science 46, pp. 175–184. Misra, S.K, 2003.Seed production of pearl spot, Etroplus suratensis .Aquaculture Conference in 8 th Aquaculture Expo 2003, Orissa, India. Perez –Ruzafa, A., Diego, C.M, and J.D. Ros, 1991. Environmental and biological changes related to recent human activities in the Mar Menor (SE of Spain). Mar. Pollut. Bull ., 23: pp. 747 -751. Pillai. C Thankappan ,1984. Handbook on diagnosis and control of bacterial diseases in finfish and shellfish culture.CMFRI Special Publication , 17. pp. 1-36. Tytler, P. and J. H. S. Blaxter, 1988. The effects of external salinity on the drinking rates of the larvae of herring, plaice and cod. Journal of Experimental Biology 138, pp. 1-15. Ward, J. A. and R.L. Wyman, 1977. Ethology and ecology of cichlid fishes of the genus Etroplus in Sri Lanka: Preliminary findings. Environmental Biology of Fishes 2(2), pp.137-145.

POSSIBLE SOLUTIONS MITIGATING POLLUTION AT KANDY LAKE, SRI LANKA

K.B.S.N.Jinadasa 1, C.S.Kalpage 2, G.B.B.Herath 1. C Devendra 3, W.J. Ng 4, S.K. Tan 4

1Department of Civil Engineering, University of Peradeniya, Sri Lanka. 2Department of Chemical and Process Engineering, University of Peradeniya, Sri Lanka. 3Department of Irrigation, Regional Director’s office, Kandy, Sri Lanka. 4Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological University, Singapore

ABSTRACT Kandy, because of its historical and cultural significance, is recognized as a UNESCO world heritage city. The sacred Buddhist Temple of the Tooth is located in the city’s centre facing Kandy Lake. The lake which covers an area of about 0.25 km2 was constructed between 1810 and 1812 by the last Kandayan King, Sri Wickrama Rajasinghe, as an ornamental and water storage lake. Presently many tourist service establishments are located around the lake and utilizing its aesthetic appeal to attract visitors—making it a focal point for large numbers of local as well as overseas visitors and pilgrims. Despite its key location and function in Kandy’s cultural life and tourism industry, inadequately regulated urbanization and waste disposal and management facilities have resulted in serious pollution of the lake from discharges into the waterways feeding the lake. The population of Kandy is around 120,000 but it experiences a two- to three-fold increase during the internationally renowned Esela festival season in August. A systematic approach and integrated remedial measures should be taken to develop a sustainable water quality improvement plan to mitigate pollution in Kandy Lake for the benefit of the Kandy community and their cultural heritage.

1.0 INTRODUCTION Kandy is the second largest city in Sri Lanka. It is also home to the Temple of Tooth Relic and thus a pilgrimage destination to the Buddhists. In 1988, Kandy was declared as a world heritage city by UNESCO. At the heart of the city lies Kandy Lake, the most scenic tourist attraction in Kandy. Unfortunately, as many water bodies in developing countries are, Kandy Lake is not spared by the negative effect of urbanization pollution. Some wastewater and storm runoff of Kandy City goes directly to the Lake or to the downstream Mid-Canal which runs through the City and eventually is discharged to Mahaweli River, which is the longest river in Sri Lanka. In addition, illegal wastewater discharge is also prevalent along the Mid-Canal. As a result, the Lake and the Canal face serious pollution problem. As the Lake is a world heritage site, common mechanized systems to clean the lake are avoided, and lack of space in the rapidly urbanizing city compounded the challenge. Systematic approach and integrated remedial measures are needed to

11 develop a sustainable water quality improvement plan to mitigate the pollution in Kandy Lake.

2.0 METHOD Over the past two years, this research team had conducted field and laboratory works to develop solutions to mitigate the pollution in Kandy Lake. Investigations were carried out in four domains: 1. Understanding the problem: Socio-economic survey and lake bathymetry survey, Identification of Wastewater sources, and water quality studies 2. Capability developments: Laboratory scale studies, modelling of Kandy Lake, and Pilot scale floating wetland units 3. Education: Research, Publications, and dissemination of information 4. Outreach to the Community: School Program, and Collaboration with Government Agencies

3.0 RESULTS AND DISCUSSION 3.1 Modeling This study outlined a numerical study made on Kandy Lake with the view this shall be a prelude to efforts at improving water quality therein. A number of proposals were investigated numerically to identify where the potential low water movement areas are and how the velocity of these areas can be reactivated. The simulation results revealed that when the distributed inflows are discharged into the identified ‘dead zones’, flow can be enhanced and therefore pollution risk at these locations can be reduced.

Figure 1. Kandy Lake simulation: solution

3.2 Floating Wetlands The experimental results have demonstrated the effectiveness of floating wetland systems in removing both carbonaceous and nitrogenous compounds from polluted water. Floating wetlands may be a viable option for lake restoration in tropical conditions. Compared to C. iridiflora and on the basis of water quality improvement, T. angustifolia was observed to yield better performance.. However, floating wetlands with C. iridiflora may also be anattractive option as it improves the aesthetic appearance of the treatment site. Harvesting could be a sustainable plant management option for floating wetlands and further studies are required to determine optimum harvesting cycles.

(a) (b) Figure 2: Comparison of a) BOD5 and b) NH4+-N removal efficiency variations in between two different macrophytes systems

4.0 CONCLUSIONS The key findings of this research work are: 1. Requirement for a proper Water Quality Management Plan 2. Requirement for Community awareness programmes and appropriate small scale wastewater treatment units for the community 3. Floating Wetlands as an Appropriate Technology for lake water quality remediation 4. School Education for a sustainable water resource (long term objective) 5. Wastewater Management options – further investigation is required 6. Requirement for Coordination among agencies

5.0 REFERENCES Dissanayake, C. B., Rohana Bandara, A. M., Weerasooriya, S. V. R. (1987). Heavy metal abundances in the Kandy Lake- An environmental case study from Sri Lanka. Environmental Geology, 10, 81-88. Greenway, M. (2003). Suitability of macrophytes for nutrient removal from surface flow constructed wetlands receiving secondary treated effluent in Queensland, Australia. Water Science and Technology, 48(2), 121–128. Jinadasa, K.B.S.N., Tanaka, N., Sasikala, S., Werellagama, D.R.I.B., Mowjood, M.I.M. and Ng, W.J. (2008). Impact of harvesting on constructed wetlands performance – a comparison between Scirpus grossus and Typha angustifolia. Journal of Environmental Science and Health. Part A, 43(6), 664-671. Juwarkar.A., Oke, B., Juwarkar, A., and Patnaik, S.M. (1995).Domestic wastewater treatment through constructed wetland in India, Water Science and Technology, 32(3), 291-294. Silva, E. I. L. (2003).Emergence of a Microcystis bloom in an urban water body, Kandy Lake, Sri Lanka. Current Science India, 85 (6), 723-725.

ALGAL BLOOM AND LAKE WATER QUALITY: A CASE STUDY OF TOXIN PRODUCING CYANOBACTERIA,( Cylindrospermopsis racibroskii ) IN NUWARAWEWA, ANURADHAPURA

J. K. Ariyawansa, M.I.M. Mowjood, and E.I.L. Silva 1

Postgraduate Institute of Agriculture, University of Peradeniya 1Natural Aquatic Research Centre, Sri Lanka

ABSTRACT Nuwarawewa is used for many purposes including domestic water supply. Occasionally the water in the reservoir is turbid, greenish brown in colour and odorous. A study was conducted to access the status of phytoplankton and other physiochemical parameters of water in the reservoir. Water was sampled at three sites inlet, middle of the reservoir and outlet during 2006/2007. Profile water samples were collected at the middle of the reservoir. Laboratory analysis was conducted to determine algae community and water quality parameters. Toxin producing cyanobacteria, Cylindrospermopsis racibroskii, was dominant in the lake reservoir and contributed 99.6% to the total population. Reservoir and outflow had higher density of cyanobacateria compared to the inflow water. Many species of were found in noticeable density in dry season. Algal responses for NO 3-N and PO 4-P are distinguished and thus limiting factors can be identified to control the algal growth. Phytoplankton in Nuwara wewa has unique characteristics and need a continuous monitoring and control plan particularly for dry period.

1.0 INTRODUCTION Excessive growth of blue green algae in ponds, lakes and reservoirs has become a serious water quality problem and threatens human and animal health. Nutrient rich eutrophic water bodies promote growth of blue-green algae that produce toxic chemicals. The algae hamper the treatment of water for drinking, prevent recreational use and clog pipes. Therefore, monitoring of water bodies for phytoplankton and planning preventive measures accordingly are needed for controlling the algal bloom in water bodies which are in a good and moderate status. If the water body found to be already colonized or invaded by algae, then an assessment followed by urgent actions are needed to bring them into improved status. Algal blooms have been reported in many water bodies in Sri Lanka (Abewickrama, 1979, Jayatissa, et al. 2006,). Microcystis bloomwas found in Beira Lake, Kandy Lake and Kotmale reservoir (Piyasiri, 1995, Silva and Wijerathne, 1999, Silva and Samaradiwakara 2005, Silva, 2007). A dinoflagellate species was identified in Rosmith and Dunumadalawa tanks in Kandy (Yatigammana et al, 2011) which caused a dysenteric epidemic condition in 2008. Favorable tropical climatic condition and anthropogenic nutrient loading into water bodies promote this algal blooming.

Nuwara wewa, a manmade ancient irrigation reservoir, located in the historical city of Anuradhapura in North-Central province of Sri Lanka is used for domestic water supply, irrigation, and fishing and recreational purposes. The water spread area is 1012 ha. The maximum capacity is 29.2 MCM. It was noticed that the water in the reservoir turbid, greenish brown in colour and occasionally smell (odorous). A study was conducted to determine the status of phytoplankton and other physiochemical parameters of water in the reservoir with a view to propose potential mitigation measures.

2.0 MATERIAL AND METHODS A monitoring of phytoplankton densities and species composition along with physiochemical properties of water was carried out monthly, for a period of one year from December 2006. As shown in Figure 1, the water was investigated at inflow, middle of the tank and at the outlet of the tank. Water samples were collected using 1L Rutner sampler from the surface in addition to stratified samples at depths of 0.5m, 1m, 1.5m and 2m.

Outle t

Centre of the tank

Inlet

Figure 1: Nuwarawewa and the locations for sampling points Net sample of phytoplankton for identification of taxonomic composition were collected from each station by towing 55 µm mesh size Wisconsin plankton net. The sample was immediately fixed with Lugol’s solution for quantitative assessment of phytoplankton density and identification of species composition.

A known volume of each water sample was filtered through Whatman GF/C circles (0.45µm pore size and 47mm in diameter) using a Millipore - filtering manifold. The filtrate was used to determine NO 3 -N and dissolved phosphorous. Nitrate-N was determined following the diozotization method (APHA 1989). Unfiltered samples were also used to determine pH, alkalinity, conductivity, Total Suspended Solid (TSS), turbidity and BOD 5. Laboratorial analysis were conducted at the Institute of Fundamental Science (IFS), Kandy, Agri-Biotechnology Centre, University of Peradeniya.

3.0 RESULTS AND DISCUSSION 3.1 Composition and abundance of phytoplankton Twenty one species of phytoplankton belonging to six families were identified to the generic level in Nuwarawewa. Table 1 depicts the composition and relative abundance of major taxonomic groups of phytoplankton recorded during the study period in the reservoir and inlet and outlet of the water body. Among these taxonomic groups, the family cyanophyceae which produce harmful toxin was the most diverse group and contributed 99.6% to the total population. The species within the family cyanophyceae also has varied. Compare to the other species Cylindrospermopsis raciborskii (Plate 1) was the most dominant . Chroococcus sp was present moderately. Merismopaedia punctata and Spirulina sp were found rarely in the reservoir. Species composition of Diatomophyceae was very small. However, the species composition in Nuwarawewa may be more than the reported as small phytoplankton species go through the 55 µm mesh.

Plate 1: Phytoplankton species ( Cylindrospermopsis racibroskii and Anabinopsis sp )

Table 1: Species composition of phytoplankton in Nuwarawewa during the period under study (d-dominant, m-moderate, r-rare) Phytoplankton Species Inlet Lake Outlet Cyanophyceae Anabaena sp (curved) - - - Anabinopsis circularis - r r Chroococcus sp m m m Cylindrospermopsis raciborskii d d d Merismopaedia punctata - r r Microcystis aeruginosa m - - Microcystis incerta - r - Microcystis wesenbergii - r - Oscillatoria raciborskii m - - Planktolyngbia circumereta - - - Pseudoanabaena galeata - - - Spirulina Sp m r r Glieocaosa sp r r - Diatomophyceae Aulacoseira granulata r r - Navicula sp r r - Urozelania detriculata - r r Pinnularia sp r r - Dinophyceae Peridinopsis pygmaeum - r - Chlorophyceae Ankistrodesmus bernadii - - - Ceolastrum astroideum - - - Crucigenia tetrapedia - - - Oocystiss - - - Pediastrum simplex r r - Scenedesmus sp - m - Mougeotia sp r - -

Zygnemaphyceae Closterium aciculare - r - Cosmarium depressum - r - Staurastrum nodulosum - - - Staurastrum tetracerumnodulosum - - - Euglenophyceae Euglene sp - r r Pacus sp - - -

3.2 Variation of cyanophyceae density Algal population varied with the inlet, middle of the lake and outlet. Figure 2 shows the planktons (three families) in these 3 locations on 4 sampling time. Phytoplankton composition and density were less in the inlet compared with lake and outflow water. Higher density of cyanophyceae was found in the lake and outflow water. Diatomophyceae and Chlorophycea were not significantly detected in inlet or lake and outlet. Although this lake is fed by other tank located in the upstream, the input from inlet is very low. A significant increase in algal growth within the lake indicates that there are favorable conditions.

6000 8000 Inlet 7000 Inlet 5000 Lake Lake 6000 Outlet 4000 5000 3000 4000 3000 2000 Filaments/ml) Filaments/ml) 2000 Density (Colonies or or (Colonies Density 1000 or (Colonies Density 1000 0 0 Cyanophyceae Diatomophyceae Chlorophyceae Cyanophyceae Diatomophyceae Chlorophyceae Figure 2a Figure 2b 7000 60000 6000 Inlet Inlet Lake 50000 5000 Outlet Lake 4000 40000 Outlet 3000 30000

Filaments/ml) 2000 20000 Filaments/ml) Density (Colonies or or (Colonies Density

1000 or (Colonies Density 10000 0 Cyanophyceae Diatomophyceae Chlorophyceae 0 Cyanophyceae Diatomophyceae Chlorophyceae Figure 2c Figure 2d Figure 2: Comparison of planktons in inlet, lake and outflow water (a - 6th Dec 2006, b - 24 th Jan 2007, c - 7th Feb 2007, d - 14 th Jun 2007)

Phytoplankton density was reduced from the surface to bottom. High density of cynabacteria was found at sub surface layers at 50 cm depth from the surface compare to surface and deeper water layers. Weather condition of the day will affect the vertical distribution of phytoplankton in the lakes. Phytoplankton move to the bottom of the lake when the density increases (Silva, 2006).

70000 0 0.5m 1m 2m 60000 50000 40000 30000 Density (Colonies/ml) Density 20000 10000 0

Dates of sampling Figure 3 Changes of cyanophyceae density in the vertical profile of lake 3.3 Density and composition of cyanophyceae during wet and dry period Variation of phytoplankton in the reservoir over time is illustrated in Figure 4. It was observed that phytoplankton increased very drastically in June and August 2007 during which the water level has decreased. Water level varied between 3 – 4 m. The composition and relative abundance varied in wet and dry seasons. Many species were visible in measurable quantities in the dry season as shown in Figure 5. Species Pseudoanabaena galeata and Planktolyngbia circumereta werenot noticed in wet season butappeared in the dry season.

120 l

100

0 Phytoplankton density/colonies*1000/m Phytoplankton

Date of sampling

Figure 4: Total phytoplankton density changes during the study period

Microcystis sp3

Anacystis sp 50 Glieocaosa sp 83 125 Spirulina Sp 75 Pseudoanabaena galeata 173 3 Planktolyngbia circumereta 125 Oscillatoria raciborskii 17 125 Microcystis aeruginosa 783 475 Merismopaedia punctata 300 4060 Cylindrospermopsis raciborskii 4770 100 125 0 Chroococcus sp 200 Anabinopsis circularis

Anabaena sp (curved) Outlet Lake Inlet 0 2000 4000 6000 0 2000 4000 6000

Figure 5: Composition and abundance of cyanophyceae during wet and dry seasons

3.4 Phytoplankton density and physicochemical parameters Although many physiochemical parameters were measured, only few of them are presented in Table 2. As in Figure 6 the relationship between the cumulative concentrations of NO 3-N, PO 4-P and cumulative phytoplankton density shows that the rate of change of algal growth with respect to the rate of change of nutrients. Accordingly, Nitrate nitrogen and algal growth had a good correlation. C. racibroskii is a nitrogen fixing cyanobacteria which grows lavishly in low nitrogen conditions when P is sufficient. On the other hand, the PO 4-P shows two clear responses at lower concentration and high concentration. Lower response of algal growth at lower concentration indicates that P is a limiting factor. Table 2 Physiochemical parameters of lake water

NO 3 - N PO 4 - P EC TSS Phytoplankton (mg/L) (mg/L) (µS/cm) (mg/L) density (colonies/ml) 06.12.2006 0.238 0.186 370 0.50 5535 20.12.2006 0.258 0.210 364 0.23 4865 10.01.2007 0.536 0.118 302 0.10 6715 24.01.2007 0.432 0.206 288 0.30 7055 06.02.2007 0.425 0.003 327 0.45 5860 21.03.2007 0.420 0.020 302 0.51 6255

40000 35000 30000 25000 20000 15000 10000 density (colonies/ml) density 5000 CumulativePhytoplankton 0 0 0.5 1 1.5 2 2.5

Cumulative NO 3 - N (mg/L)

40000 35000 30000 25000 20000 15000 10000

density (colonies/ml) density 5000 CumulativePhytoplankton 0 0 0.2 0.4 0.6 0.8

Cumultive PO 4-P (mg/L)

Figure 6: Cumulative phytoplankton density with cumulative NO 3-N and PO 4-P

4.0 CONCLUSION Twenty one species of phytoplankton belonging to six families were identified in Nuwarawewa. Family cyanophyceae which has toxin producing capacity was the most diverse group and contributed 99.6% to the total population. Higher density of cyanobacateria was found in the lake and outflow water compared to the inflow water. The composition and abundance clearly varied between wet and dry season. Higher concentrations of many species were found in dry season. Algal responses on NO 3-N and PO 4-P vary and thus limiting factors can be identified to control the algal growth. Phytoplankton in Nuwara wewa has unique characteristics compare to other reservoirs in Sri Lanka and need to be kept under monitoring continuously.

5.0 REFERENCES Abewickrama, B.A., 1979. The genera of the fresh water algae of Sri Lanka.Pare1- UNESCO man & Biosphere National Commiittee for Sri Lanka.Special publication 06. National Science Council Sri Lanka, Colombo, pp 103. APHA, 1989.Standard Methods for Estimation of Water & Waste Water, 17th Edition, American public Health Association, Washinton Dc. Jayatissa, L.P, E.I.L. Silva, J. McElhiney and L.A. Lawton 2006. Occurrence of toxigenic cynobacterial blooms in freshwaters of Sri Lanka. Systematic and Applied Microbiology 29: 156-164. Piyasiri, S. 1995. Eutrophication and algae problem in Kotmale reservoir, Sri Lanka , K.H. timotius and Goltenboth (eds), Tropical Limnology vol. 2, Satyas, Waccana University press, Salatiga, Indonesia. Silva, E.I.L. and M.J.S. Wijerathne. 1999. The occuerence of Cyanobacteria in the reservoirs of the Mahaweli river basin in Sri Lanka. SL.J. Aquat.Sci.4: 51-60.

Silva, E.I.L & S.R.M.S. Samaradiwakara 2005.Limnology of Kandy Lake before the outbreak of a cyanobacteria bloom in May 1999. III. Phytoplankton composition and succession. Sri Lanka Journal of Aquatic Sciences 10: 55-71. Silva, E.I.L 2007.Hypertrophic-eutrophic alteration in Kandy Lake, following an outbreak of a Mycrocystis bloom. Sri Lanka. J. Aquat. Sci. 12:115-120. Yatigammana, S.K., Ileperuma, O.A. and Perera, M.B.U, 2011. Water pollution due to harmfl algal bloom : a preliminary study from two drinking water reservoirs in Kandy, Sri Lanka. J. of Natn. Sci. Foundation Sri Lanka 39 (1): 91-94.

MIXING STATES OF KOGGALA LAGOON IN DRY SEASON

E. Furusato 1, G. P. Amarasekara 2, S. Yasuda 3, T. Priyadarshana 2 and N. Tanaka 1, 4

1 Graduate School of Science and Engineering, Saitama University, Japan 2Faculty of Fisheries and Marine Sciences & Technology,University of Ruhuna 3River and Water Resources Division,CTI Engineering Co. Ltd., Japan 2 Environmental Science & Technology,Saitama University, Japan

ABSTRACT A field observation was conducted on 16 March 2012 to estimate the salinity level and density stratification of Koggala lagoon in dry season. Vertical variation of salinity, temperature and dissolved oxygen of water in the lagoon were measured with the conditions of neap and flood. The same measurements also were alsotaken from inflow streams. The observations indicate that not only water in the mouth of the lagoon but also water inside the main lagoon was strongly mixed. Compared to the previous results of field observation conducted in monsoon season, water in both the lagoon mouth and inside the lagoon exhibit the state of strong mixing and high salinity. The effects of seasonal changes of rainfall on the salinity level and mixing condition of Koggala lagoon is discussed.

1.0 INTRODUCTION Koggala lagoon is one of the forty-three coastal lagoons encircling the coastal belt of Sri Lanka. The salinity level of this lagoon has increased due to the large amount of seawater intrusion by some human interventions such as sand bar removal and groyne construction. These physico-chemical changes lead to various problems such as socio-economical problems as well as natural ecosystem degradation in and around the lagoon(Priyadarshana et al. 2007). Thus, countermeasures for this issue are required. Previous studies have pointed out that the importance of lagoon mouth morphology for the restoration of lagoon environment (Priyadarshana et al. 2007, Gunaratne et al. 2010). By using hydrological parameters, an improved salinity level of the lagoon will be obtained with a new rubble mound structure proposed by the authors. With the modifications it is expected that the ecosystem and the water quality of the lagoon would reverse to a more freshwater-oriented system. However, generally human impact will cause various unexpected effects on water bodies particularly complex systems like lagoons. Furusato et al. (2012) reported that Koggala lagoon was strongly salinity stratified in the monsoon season. Generally, the inflow discharge from a river or streams affects the mixing states of an estuary(Fisher 1972, Hansen and Rattay 1966). For understanding current states of stratification of Koggala lagoon, surveys are to be conducted in different seasons. The objective of this study is to estimate the mixing state of Koggala lagoon in the dry season.

2.0 MATERIALS AND METHODS 2.1 Study sites Koggala lagoon is located in the southern coast of Sri Lanka (Fig. 1). Hydro-catchment area of the lagoon outlet is about 55 km 2, of which about 15% is the lagoon area. It is estimated to have further 15% of paddy fields or low lying areas (Priyadarshana et al., 2007). The water depth ranges from 1.0 to 3.7 m (IWMI, 2006). The coastal lagoon is essentially fed by rain and a number of streams connected to it. Warabokka stream (Koggala-oya) enters the lagoon from the north-west. Kerena anicut was built combining both the streams named as Mudiyansege stream and Thithagalla stream. Heen stream contributes slightly to the water inflow. Apart from these three streams, Kahanda stream, Gurukanda stream, and Thelambu stream were contributors for inflow but presently these are abandoned and have become marsh lands with almost zero water flow due to overgrown vegetations. The only outlet of the lagoon is Pol- oya located at the southeast corner; a narrow 300 m long canal connects the lagoon with the sea.

H-1 K-1

W-1

M-4 L-4 L-3 L-2 M-1 M-3 L-1 M-2 O-2

O-1 0.5km 0.5km Figure 1: Koggala lagoon and survey points.

2.2 Field observations Field observations to estimate the present states of density stratification of Koggala lagoon in the dry season were conducted. The observations were done on 16 March 2012. The survey was done in the dry season after the northwest monsoon season (from October to February). Tidal condition of the survey day was neap. The survey from the mouth area to the upstream station was done from 10 am to 5 pm. Figure 1 shows the survey points in Koggala lagoon. Basically, on the same survey points in the previous study (Furusato et al. 2012),field observations were conducted. The observations of these points were used for estimating the current situation of density stratification of Koggala lagoon. A water quality measuring equipment (multi probe) YSI Model 55 was used to obtain vertical profiles of temperature (WT), salinity, and dissolved oxygen (DO) (approx. 0.5 m intervals). At lagoon mouth area (M-2), temporal changes of water temperature and salinity in vertical profiles were measured by a water quality measuring equipment TOA DKK Model CM-31P. In addition,

26 temporal changes in the surface velocity were measured by a flow velocity meter - KENEK VP 1000 at the left bank of M-2.

3.0 RESULTS AND DISCUSSION 3.1 Temporal changes in salinity and velocity of lagoon mouth area Figure 2 shows the temporal changes in salinity, water temperature, and velocity (seawards positive) measured at the surface of Lagoon mouth area (M- 2). During the flood condition, all these three parameters did not exhibit remarkable water temporal changes. Fig. 3 shows the temporal changes in vertical profiles of water temperature and salinity at M2. For both the parameters, vertical profiles were uniform throughout the survey time. The mixing state of the lagoon mouth area was strong.

Salinity WT Velocity

35 0.9

] s] / ] [‰30 0.6 m ℃ y [ [ it y T n it it c W l lo a25 0.3 e S V

20 0 10:00 11:00 12:00 13:00 14:00 15:00

Figure 2: Temporal changes in water temperature, salinity and velocity (seawards positive) measured at surface on lagoon mouth area (M-2). 3.2 Spatial distribution of measured parameters In this section, the characteristics of density stratification and other related phenomena are described for each area surveyed. Lagoon mouth area Figure 4 shows the vertical profiles of each measured parameter of the lagoon mouth area. These measurements were made during the flood. All the measured parameters exhibit similar uniform vertical profiles. This means that on this survey conditions, the water body of this area was strongly mixed.

Salinity [ppt] WT [℃] 29.5 30 30.5 30 30.5 31 31.5 32 0 0

1 1 ] ] m m [ [ h h t pt ep 10:30 e d 2 11:00 d 2 12:00 13:00 3 14:00 3 15:00

Figure 3: Temporal changes in vertical profile of water temperature and salinity during flood (point M-2).

Salinity [ppt] DO [%] WT [℃] 0 10 20 30 0 50 100 28 30 32 0 0 0

1 ] 1 ] 1 ] m [m [m [ h th th t p p p e 2 M-2 e 2 e 2 d d d M-3 3 M-4 3 3

Figure 4: Vertical profiles of each measured parameter in the lagoon mouth area. The symbols in each legend mean survey stations (see Fig 1).

Koggala Lagoon Figure 5 shows the vertical profiles of some parameters measured in Koggala lagoon. For comparison, the measured values at the upstream end of the mouth area (M-4) and the representative inflow stream (W-1) are also shown. The vertical profile of salinity shows a similar trend for each point. Salinity level of the surface was about 30 ppt. At the deep layer of the centre area (L-1), a slightly high salinity bottom layer exists. The water temperature and DO exhibit a similar trend at L-1. Below 1m depth the high water temperature and relatively low DO concentration were confirmed. This means that deep layer water parcels remain without a strong mixing with the surface layer for a certain period.

Salinity [ppt] DO [%] WT [℃] 0 10 20 30 0 50 100 28 30 32 34 36 0 0 0

M-4DO [%] 0 50 ] 1 ] 1 ] 1 0 m m m [ [ [ L-1 h h h t 1 L-2 p pt pt ] m e 2 e 2 e 2 [ th p e d d d d L-3 2 L-4

3 3 3 3 W-1

Figure 5: Vertical profiles of each parameter of Koggala lagoon.The symbols in each legend mean survey stations (see Fig 1).

Salinity [ppt] DO [%] WT [℃] 0 10 20 30 0 50 100 28 30 32 34 36 0 0 0

] 1 ] 1 ] m m m 1 [ [ [ h h h pt t t e 2 ep 2 p 2 W-1 d d de H-1-U 3 3 3 H-1-D K-1

Figure 6:Observation results of inflow stream.The symbols in each legend mean survey stations (see Fig 1).

Inflow streams As shown in Figure 4, the inflow streams exhibit a stratification of salinity and water temperature. The range of surface salinity was 0.8 ～4.4 ppt depending on each stream. On the other hand, below the surface depth, the same salinity level was measured for each station in the streams. The brackish water supply from the inflow streams corresponds to the effects of permanently open- mouth to Koggala lagoon as reported by Priyadarshana et al. (2007). The important point is the salinity stratification of inflow streams. Raining before this survey is to be the possible reason to have a fresh water layer in the stream. However, the low level of salinity in the surface water body which is less than 10 ppt was not found in the lagoon. This means that the low salinity of surface water of inflow stream would be probably mixed in surface plumes due to the shear stress by wind. However, there are no detailed evidences for such an explanation. This is also one of the problems unresolved. 3.3 Comparison of spatial distribution of salinity in dry season with monsoon season Vertical distribution Figure 7 shows the comparison between each measured parameters during the monsoon season (22/Nov-2011) and dry season. The parameters exhibit differences depending on the weather conditions. As reported by previous study (Furusato et al. 2012), in the monsoon season, partially mixing of the mouth area and strong density stratification of both the lagoon and inflow stream were measured. On the other hand, the results of survey in the dry season indicated that such mixing states of Koggala lagoon differ depending on the season.

Figure 7: Comparison of measured parameters between dry and monsoon seasons.The symbols in each legend mean survey stations (see Fig 1)

600 ] th500 n o m400 / m 300 [m l fa200 n ai R100 0 n b r r y n l g p t v c n b a e a p a u u u e c o e a e J F M A M J J A S O N D J F 2011 2012

Figure 8: Comparison of measured parameters between dry and monsoon seasons (Galle).

Figure 8 shows the monthly rainfall measured at Galle. Generally, rainfall of Sri Lanka is seasonally influenced by the southwest monsoon (May to September) and northeast monsoon (December to February) (Suppiah and Yoshino 1984). There was very little rainfall in January and February 2012 compared to heavy rainfalls in November 2011. Hume et al. (2007) reported that many factors such as climate, oceanic, riverine, and catchment property determine the physical and biological characteristics of estuaries. However, inflow discharge from streams of a river is one of important factor for

30 determining the mixing state of estuaries including coastal lagoons (Fisher 1972, Hansen and Rattay 1966). The difference of inflow discharge from streams caused by the amount of rainfall will lead these different vertical profiles of salinity in Koggala lagoon.

40 Nov. 2011 Mar. 2012 t] p [p30 y it lin a20 s ce fa ur 10 S

0 -0.5 0.5 1.5 2.5 3.5 Distance from mouth end [km]

Figure 9: Comparison of longitudinal surface salinity distribution between dry and monsoon. Longitudinal distributions Figure 9 shows the comparison of surface salinity between the monsoon (Nov. 2011) and dry season (Mar.2012). As above described, the salinity level of Koggala lagoon measured in dry season were similar to the seawater salinity. Only for the inflow streams, the low salinity water was confirmed. On the other hand, a different longitudinal salinity distribution has been measured at the monsoon season. Considering the vertical profiles of salinity in each point, brackish water area move longitudinally depending on the season. Different mixing states of Koggala lagoon with seasons Based on the above survey results and discussion, we proposed different seasonal mixing states of Koggala lagoon (Figure 10). Koggala lagoon exhibits an entirely different mixing state depending on the season. In the rainy and monsoon seasons, the lagoon was brackish and a salinity stratified water body (Fig. 10 (a)). On the other hand, in the dry season, the lagoon was high saline concentration and strongly mixed (Fig. 10 (b)). In this season, only in the inflow stream, brackish and salinity stratification could be confirmed. The reason of this seasonal difference is to be the difference of inflow stream discharge caused by the seasonal rainfall variations. As Gunaratne et al. (2010) reported the balance of inflow quantity from the catchment and lagoon differs from the monsoon season. This hydraulic characteristics affect not only salinity level but also mixing state of the Koggala lagoon.

Figure 10: Different mixing characteristics of Koggala lagoon depending on season.

4.0 FUTURE VIEWPOINT OF RESEARCH ON KOGGALA LAGOON Before human interventions such as removal of a natural sand bar and construction of a groyne, in the dry season, the natural sand bar closed intermittently the mouth of Koggala lagoon (Priyadarshana et al. 2007). As a result, not only the water budget but also the mixing state of Koggala lagoon is influenced by seawater largely because of the opened mouth of the lagoon. Gunaratne et al. (2011) stated the possibility of improving the salinity condition of Koggala lagoon by modifying the lagoon mouth (see scenario KS2 in Gunaratne et al. 2011). Furusato et al. (2012) pointed out based on the survey results conducted in the monsoon rainy season, in the centre area of lagoon “high saline and high temperature bottom layer” was available. From the survey results reported by this paper, although there was a weak salinity stratification, we found the bottom layer with high saline and high temperature and low DO in the dry season. The characteristics of the bottom layer wassimilar to that of rainy season. Decrease in the effects of seawater in the future leads to generally a strong stratification and increase in residence time of the deep layer. This may leads the possibility of decrease in DO concentration. Generally, physical and chemical processes are basis of an ecosystem. In the future, for the proper management of Koggala lagoon, the research focusing on density stratification

32 will be needed. Furthermore, the knowledge about the relationship between the conditions of the lagoon mouth and internal processes of the lagoon likely density stratification will be needed for the sustainable development of coastal areas in Sri Lanka.

5.0 ACKNOWLEDGMENTS This study was supported in part by JSPS AA Science Platform Program, Japan.

6.0 REFERENCES Fisher, H. B. 1972. Mass transport mechanisms in partially stratified estuaries, J. Fluid Mechanics. 53: 671-687. Furusato, E., Amarasekara, G. P., Priyadarshana, T. and Tanaka, N. 2012. The Current Status of Density Stratification of Koggala Lagoon ，Symposium Proceedings of ACEPS (International Symposium on Advances in Civil and Environmental Engineering Practices for Sustainable Development), pp.176-189. Gunaratne, G. L., Tanaka, N., Amarasekara, P., Priyadarshana, T. And Manatunge, J.2010.Restoration of Koggala lagoon: Modelling approach in evaluating lagoon water budget and flow characteristics, J. Environmental Sciences.22: 813–819. Gunaratne, G. L., Tanaka, N., Priyadarshana, T. and Manatunge, J. 2011.Human intervention triggered changes to inlet hydrodynamics and tidal flushing of Koggala lagoon, Sri Lanka, in Amo, B. W., “Conditions for enterprenerurship in Sri Lanka: A Handbook”, Shaker Verlag, Germany, pp. 347-368. Hansen, D. V. and Rattay, M. 1966.New dimensions in estuary classification, Limnology and Oceanography. 11: 319-326. Hume, T., Snelder, T., Weatherhead, M. and Liefting, R. 2007.A controlling factor approach to estuary classification, Ocean & Coastal Managements. 50: 905-929. IWMI (International Water Management Institute) 2006.Sri Lanka Wetlands Database. http://dw.iwmi.org/wetland/wetlandsinfooptions.aspx?wetlandname=Koggala%20L agoon&wetland / (accessed February 10, 2011). Priyadarshana, T., Manatunge, J. and Wijeratne, N. 2007. Report, Impacts and Consequences of Removal of the Sand Bar at the Koggala Lagoon Mouth & Rehabilitation of the Lagoon Mouth to Restore Natural Suppiah, R. and Yoshino, M. M. 1984. Rainfall variation of Sri Lanka Part 1: Spatial and temporal patterns, arc. Met.Geoph.Biosl. Ser. B 34: 329-340.

FIRST FIELD EXPERIENCE ON APPLICATION OF FLOATING WETLAND IN URBAN LAKE WATER RESTORATION IN SRI LANKA

S.K.Weragoda 1, K.S.B.N. Jinadasa 2* and Ng Wun Jern 3

1Plant Engineer, National Water Supply and Drainage Board, Kandy, Sri Lanka. 2Senior Lecturer, Department of Civil Engineering, University of Peradeniya, Sri Lanka. 3Professor& Executive Director, Nanyang Environment & Water Research Institute (NEWRI), Singapore

ABSTRACT Incidence of lakepollution in developing countries has increased rapidly due to urbanization. Consequently there is need to identify feasible mitigation measures. The latter has to address issues including eutrophication and deteriorated water quality, space constraints for treatment facilities, and affordability. This study was conducted to determine possible application of floating wetlands for lake water remediation. Two types of macrophytes, Typha angustifolia and Canna iridiflora, were employed in the pilot scale study of the floating wetland system. Water quality was monitored for the + removal of BOD 5 and inorganic nitrogen. Over 80% of BOD 5 and NH 4 -N removal was - noted while NO 3 -N removal was over 40% in batch experiments. Such performance was again noted the with continuous flow regime. Root growth and density of T. angustifolia was higher than that of C. iridiflora, resulting in comparatively better performance by T. angustifolia. Floating wetlands with T. angustifolia will be a possible solution for lake restoration where the constraints of space and costs are faced. Keywords:Eutrophication, Floating wetlands, Lake, Water quality restoration

1.0 INTRODUCTION Kandy (N 7° 17' 47”, E 80° 38' 6”), capital city of the last Sri Lankan kingdom, is recognized as a world heritage city by UNESCO for its archeological importance. Kandy Lake is one of the most important manmade structures within the city, constructed during 1810- 1812 A.D. The lake covers an area of 0.18 km 2 and has a maximum depth of 13m. It has a capacity of 0.348x10 6 m3 within a perimeter of 3.25 km [1]. Recreational activity other than paddle boats is prohibited and the lake water is used neither for irrigation nor any other domestic activity as it has been polluted due to inadequately treated effluent discharges and surface runoff. It has been reported in previous studies Kandy Lake has been enriched with P and N compounds and polluted with heavy metals [1]. Typically, the first flush of storm water from the adjoining residential and commercial areas is a major cause of pollution in similar settings where a lake is surrounded by urban settlements [2]. In addition, the increasing resident bird and animal population, such as cormorants (about 250) and bats (about 2500), makes direct contribution to the lake’s nutrient pool [1]. Quality of lake water is also noted to change seasonally in response to rainfall. Kandy Lake water had been studied

35 for several metal ions and the Fe 2+ concentration (> 100 µg/l) had increased from shore towards the deepest point. The latter is between the sluice gate and the island at the lake’s centre [3]. This had suggested increasingly reducing conditions prevailed. Because of high vehicular traffic on the peripheral roads around the lake, pollutants associated with vehicular emissions such as Pb have likely entered the lake while Zn and Cd have been added by discharges from the small scale industries scattered in the lake catchment [3]. High fish mortality had been observed from mid to end of year 2009, with a maximum of 150 kills/day reported. Although using wastewater treatment plants to purify wastewater prior to its entry into the lake is technically feasible, space constraint is an issue given the very build-up nature of the land around the lake. This meant the solution should preferably be workable away from land and floating wetlands may represent a potentially suitable solution for improving the lake water quality. Potential advantages of this approach include: 1) improvement of the water quality, 2) aesthetics associated with the greening, 3) relatively simple installation, 4) relatively low maintenance requirements, 5) above water plant growth provides nesting space for birds, 6) while below water plant growth provides spawning space for fish, and 7) the overall plant growth provides shadowing and cooling for the shallow water body. Artificially created floating wetlands have been used for a limited range of applications to date, such as water quality improvement and habitat enhancement [4], and enhancing aesthetics at ornamental ponds and lakes. In terms of water quality improvement, the main application had been the treatment of storm water, combined storm water-sewer overflow, sewage [5], acid mine drainage, piggery effluent [6], poultry processing waste water, and water supply reservoirs [7]. However, much of such work had not been done under tropical conditions. Based on this background, this study had seeked to investigate the applicability of the floating wetland system for lake restoration under tropical conditions as in Sri Lanka. The study aimed to establish general guidelines for such an application.

2.0 OBJECTIVES AND METHODOLOGY The study’s objective was to evaluate performance of a pilot scale floating wetland system for lake water remediation in the tropical climate. The study had the following sub-objectives: 1. Develop a floating wetland system using locally available materials which have sufficient buoyancy and service life under the prevailing ambient conditions. 2. Compare the plant growth characteristics and nutrient removal capabilities of two emergent macrophytes ( Typha angustifolia and Canna iridiflora ) in a pilot scale floating wetland system under batch and continues flow regimes.

2.1 Design of floating mats The study was conducted at the Bio-technical Research Center (Faculty of Agriculture, University of Peradeniya, Sri Lanka). Three existing and identical tanks were allocated for the experimental floating wetland system. Each floating wetland module (100 x 50 cm 2) comprised a float for buoyancy and a frame (constructed from PVC pipes) for supporting the target vegetation growth on the media, media for growing the vegetation (comprising coconut coir pith held together with a 50 mm GI mesh), anchors (comprising cement weights), and starter plants. The coconut coir pith was obtained fresh from local coconut producers at plantations and each module had 15.6 kg of it. Total weight of the module (initially) was 18.3 kg and the maximum weight that could be carried by the module before it sank was estimated at 25.4 kg. This allowed maximum vegetation weight (following growth) of 7.1 kg. T. angustifolia and C .iridiflora were selected for the study since these were locally available in Kandy. Macrophytes of approximately 20 cm shoot height were chosen as the starter plants and planted in the floating wetland units with a density of 10 plants/ m 2. 2.2 Experimental procedure Batch condition The floating wetland system was tested in batch mode with 12-14 days hydraulic retention time. After conditioning in tap water for a week, the two floating wetland units were placed in the tanks of 1 m X 3m which have been filled with wastewater drawn from the Akbar Hall of Residence at Faculty of Engineering, University of Peradeniya, Sri Lanka. A control tank was maintained near to the tanks with the floating wetland units. Experiments were carried out in three stages as stage 1, 2 and 3 (Stage 1 & 2 were run for long term removal efficiencies at 01 week intervals and Stage 3 for short term efficiency in daily basis) and effluent samples were taken as triplicates at each stage. These were identified as initial (prior to launch the system), intermediate, and final (prior to removal of the plants from the system). Samples were taken at the water surface and 10 cm from the inlet and + - outlet and tested for BOD 5, NH 4 -N, NO 3 -N in accordance with Standard Methods [8]. In addition, shoot heights and root depths were measured at predetermined occasion by lifting the modules out of the tanks while minimizing the disturbances to the modules. The average ambient temperature was varied in a range of 26 – 28 oC and the samples were collected at 1000 - 1100 hr to avoid the affects from diurnal variations. As there was significant rainfall was expected during the experimental period, no compensation has been countered for the calculations. Continuous flow condition Two floating wetland units, each of T. angustifolia and C .iridiflora respectively were installed in the channels under continuous flow condition.

The flow rate in the channel was 0.08 m3/hr. Given the channels’ configuration, plug flow condition could be expected. Water samples were taken intermittently and tested for the parameters identified in the above section during the 3 months experimental period.

3.0 RESULTS AND DISCUSSION 3.1 Monitoring of plant morphology Observations of the root structure and length (Figure 1) showed the growth rate of C. iridiflora is greaterthan that of T. angustifolia. The root formation was less dense in T. angustifolia but it showed a gradual increment in average shoot height throughout the experimental period. Typically fast growing plants grown in nutrient poor conditions (relative to the plant type) will often develop more extensive root systems in order to increase the surface area available for nutrient uptake. C .iridiflora shoot height increased more rapidly in the initial period and did not increase noticeably after 42 days. This suggested T. angustifolia had not matured while C .iridiflora was likely so after 42 days. After 52 days, one out of eight of the starter C .iridiflora plants was observed with flower buds. The growth rate of C. iridiflora was recordedas 3100 gDWm −2yr −1 [9] and that of T. angustifolia as 4000 gDWm −2yr −1 [10]. Observations at the pilot facility would suggest biomass production of T. angustifolia could be greater. T. angustifolia can therefore potentially impact more substantially on nutrient removal if the plants are harvested. It had been estimated C. iridiflora may remove about 85 gNm −2yr −1 by above-ground biomass harvesting [9] while T. angustifolia had been reported to remove 266 gNm −2yr −1 [11]. Hence, T. angustifolia has made a comparatively greater impact on the wetland units. 3.2 Evaluation of treatment efficiencies The study was conducted at HRT of 14 days batch holding time. The results showed C. iridiflora performed better in removal of BOD 5 than T. angustifolia (Stage 1 & 2, Table 1). The two macrophytes were able to reduce BOD 5 andremovals were comparable as the study progressed (Stage 3, Table 1). However, with the maturation of plants, C. iridiflora could improve its contribution on reduction of BOD 5 than that of T. angustifolia . Comparing two macrophytes, C. iridiflora showed a higher root growth rate at early days while root density of T. angustifolia was increased at later stage. Hence, the radial oxygen lose (ROL) in C .iridiflora could be high at early days. However, in broader sense, more dense root could have released more ROL and provided more surface for microbial biofilms to form and hence more treatment have been encountered at the later parts of stage 2 &3 of the batch experiments.

2.0 – 5.0 3.0 – 10.0 a) After 4 weeks

25.0 – 30.0 20.0 – 25.0 b) After 6 weeks

35.0– 40.0 30.0 – 35.0 c) After 8 weeks C. iridiflora T. angustifolia Figure 1: Comparison of the root development patterns of T. angustifolia and C .iridiflora at different time intervals ( all values are in cm ) ROL creates aerobic conditions in the rhizosphere. The oxygen transfer rate to below ground had been estimated at about 80 gm -2day -1 in a mature wetland system [12]. The macrophyte root and rhizomes in the rhizosphere leak oxygen into microzones. This oxygen would stimulate breakdown of carbonaceous -1 compounds resulting in BOD 5 removal of 78–91% at 165–237 mgl influent BOD concentrations with T. angustifolia [13].

On the hand, N removal has varied with the type of macrophytes (Table 2). As well, there was no significant different at the presence and absence of floating wetland systems ( p<0.05 ). This could be created due to the interference of high algae growth in the control system. However, the algal growth was + controlled in the planted systems due to the competition for nutrients. NH 4 -N - and NO 3 -N removal efficiencies were recorded over 80% and 40% respectively after 14 days since starting each stage of the experiment in floated wetland systems.

Table 1: The variation of BOD 5 removal efficiency of each macrophytes specie with the time (n=3) -1 Days BOD 5 values (mgl ) BOD 5 removal efficiency (%) T. C Control T. C Control angustifolia .iridiflora angustifolia .iridiflora Stage 1 0 22.1 22.1 22.1 7 11.3 5.5 15.8 48.5 75.3 28.6 14 10.3 3.3 10.4 53.2 85.0 53.0 Stage 2 0 20.1 20.1 20.1 7 8.8 7.3 9.2 56.2 63.5 54.4 14 4.8 5.8 6.6 76.1 71.3 67.4 Stage 3 0 28.1 28.1 28.1 1 20.2 21.6 26.3 28.1 23.1 6.4 2 13.7 15.3 22.0 51.2 45.6 21.7 3 10.2 12.3 19.6 63.7 56.2 30.2 4 8.5 9.7 18.8 69.8 65.5 33.1

Table 2: Comparison of the averaged nitrogen removal efficiencies (%) of two floating wetland systems with time (n=6)

Sampling -1 Removal efficiency Wetland Concentration (mgl ) duration (%) system (days) + - + - NH 4 -N NO 3 -N NH 4 -N NO 3 -N 0 25.0 7.8 Control 7 13.8 - 44.8 - 14 6.9 4.4 72.4 43.6 0 25.0 7.8 T. 7 12.5 2.7 50.0 65.4 angustifolia 14 3.4 4.6 86.4 41.0 0 25.0 7.8 C .iridiflora 7 10.4 3.3 58.4 57.7 14 4.6 3.9 81.6 50.0

The basic water quality parameter variations of the continuous systems are shown in Table 3. Similar to the batch system, continues systems also performed better at most of the times with T. angustifolia. T he removal + + efficiency of BOD 5 and NH 4 -N are illustrated in Figure 2. BOD 5, NH 4 -N and 3- PO 4 -P removal efficiencies were over 90% in both systems after 50 days since the installation at the site. However, there was no significant difference in removal efficiencies between two macrophyte systems ( p< 0.05). Referring to the results of both batch and continuous flow tests, it is suggested to harvest the macrophyte after two months period as macrophytes reach their maximum shoot height and production. Hence, this will expedite removal of nutrients from the lake water to an agricultural field where uses plant biomass. However, optimum harvesting frequency for two different macrophytes would be differed and hence it is reacquired to have further experiments on wetland systems with similar species. In general, nitrification followed by denitrification, volatilization, plant + uptake and substrate adsorption are the major NH 4 -Nremoval mechanisms in a wetland system [14]. At regular ambient conditions, denitrification is probably - the most significant pathway of NO 3 -N removal from a wetland system [15]. + The loss through volatilization of NH 4 -N represented, on average, 20% of the initial concentrations at the similar pH range (7.8 – 8.4) as observed in this experiment [16]. This could be greater in the control system than planted system due to its greater exposure to the atmosphere. On the other hand, the contribution to total nitrogen removal by direct plant uptake was limited as 4-

11% [15]. Also, the adsorption by sediment might contribute extensively in nitrogen removal [15]. Usually, floating wetland systems and the root and rhizome system assist in nutrient removal by providing space for the attached growth of micro-organisms colonies, creating the bio-film, and take nutrients out of the water. Hence, when nitrogenous compounds pass through the metabolism or the micro-organisms and are thus transformed into an easier digestible form, and then the plants take them in and build with them the biomass above the water level as leaves, stems and sometimes flowers. Finally, the biomass harvesting assists in taking the excess nutrients effectively and permanently out of the water. Therefore, plant roots are believed to play a major role in treatment processes within floating wetland systems. Table 3: The variation of effluent water quality of each macrophytes specie with the time (n=3) at the continuous flow condition T. angustifolia C. iridiflora

S/cm) S/cm) µ µ ( Time (Days) (mg/l) -P(mg/l) -P(mg/l) -N (mg/l) -N (mg/l) 5 -N (mg/l) -N (mg/l) (mg/l) - + - + 3- 3- 5 3 4 3 4 4 4 BOD PO PO NO NO pH NH NH pH Conductivity ( Conductivity BOD Influ -ent 28.72 8.5 144 1.9 32.00 2.80 28.7 8.5 144 1.9 32.0 2.80 11 13.80 8.5 145 1.8 4.90 2.28 9.25 7.8 141 2.2 3.32 1.41 15 13.10 8.4 142 1.6 3.03 0.76 8.20 7.6 141 1.0 3.01 0.80 37 6.58 8.2 141 1.5 2.16 0.63 6.20 7.6 139 1.0 2.85 0.29 41 5.53 8.1 139 1.4 1.48 0.39 3.00 7.5 141 1.1 1.48 0.29 48 1.30 7.9 144 1.0 0.95 0.39 2.55 7.5 143 0.9 1.20 0.23 51 1.20 7.6 143 0.7 0.58 0.29 1.60 7.6 141 0.7 1.03 0.09 74 0.60 7.5 141 0.3 0.05 0.29 1.40 7.5 141 0.6 0.56 0.37 83 1.20 7.4 143 0.1 0.04 0.18 2.00 7.4 144 0.7 0.34 0.08 96 1.30 7.4 144 0.2 0.02 0.29 2.10 7.5 142 0.1 0.07 0.06

The experiment done with T. angustifolia planted on soil bed at the same environmental conditions and in the same experimental site showed the removal + - efficiencies of BOD 5 as 53.8%, NH 4 -N as 56.5 % and NO 3 -N as 51.6 % [17]. However, the removal efficiencies of floating wetland systems at the same environmental conditions for same plant species has shown greater values for

+ - BOD 5, and NH 4 -N while lesser values for NO 3 -N. This must be expected as floating wetland systems provide less of the anaerobic environment than the soil bed planted systems and hence aerobic activities perform well while anaerobic are retarded. However, further fundamental experimental researches are required in order to establish a relationship between loading rate per unit surface area of floating wetland. This would then enable to produce guidelines on the surface area of floating wetland systems. In addition, application of floating wetland systems at actual conditions is essential before justifying their efficiency in lake water reclamation.

100 100

80 80

TyphaT. angustifolia sp. T. angustifolia Typha sp . 60 CannaC. iridiflora sp. 60 CannaC. iridiflora sp.

Removal efficiency (%) efficiency Removal

40 40 0 20 40 60 80 100 0 20 40 60 80 100 Time (days) Time (days)

(a) (b) + Figure 2: Comparison of a) BOD 5 and b) NH 4 -N removal efficiency variations in between two different macrophytes systems

4.0 CONCLUSIONS The experimental results have proven the effectiveness of floating wetland systems in removing both carbonaceous and nitrogenous compounds from polluted water. However, comparing two macrophytes species, T. angustifolia performs well in removal of BOD 5 and inorganic nitrogen than those of C .iridiflora . However, on the other hand C. iridiflora would still be a better option for aesthetically significant locations.

5.0 REFERENCES Silva, E. I. L., “Emergence of a Microcystis bloom in an urban water body, Kandy Lake, Sri Lanka”. Curr. Sci. India , Vol. 85, No. 6, 2003, pp 723-725. Gupta A.B., Jain R. Gupta K., “Water quality management for the Talkatora Lake, Jaipur-A case study”, Water Science and Technology., Vol. 40, No. 2, 1999, pp 29- 33.

Dissanayake, C. B., Rohana Bandara, A. M., Weerasooriya, S. V. R., “Heavy metal abundances in the Kandy Lake- An environmental case study from Sri Lanka”, Environmental Geology , Vol. 10, 1987, pp 81-88. Burgess, N.D., Hirons, G.J.M., “Creation and management of artificial nesting sites for wetland birds”, Journal of Environmental Management , Vol. 34, No. 4, 1992, pp 285-295. Ash, R., Troung, P., “The use of Vetiver grass wetlands for sewerage treatment in Australia”, Proceedings of 3rd International Conference on Vetiver,Guangzhou , China , 2003. Hubbard, R.K., Gascho, G.J., Newton, G.L., “Use of floating vegetation toremove nutrients from swine lagoon wastewater”, Transactions of the ASAE , Vol. 47, No. 6, 2004, pp 1963-1972. Garbutt, P., “An investigation into the application of floating reed bed and barley straw techniques for the remediation of eutrophic waters”, WEJ , 2004, pp 174-180. APHA, “Standard Methods for the Examination of Water and Wastewater.20th Edition”, American Public Health Association, Washington, DC, USA. 1998. Konnerup, D., Koottatep, T., Brix, H., “Treatment of domestic wastewater in tropical, subsurface flow constructed wetlands planted with Canna and Heliconia”, Ecological engineering , Vol. 35, 2009, pp 248–257. Greenway, M., “Suitability of macrophytes for nutrient removal from surface flow constructed wetlands receiving secondary treated effluent in Queensland, Australia”, Water Science and Technology , Vol. 48, No. 2, 2003, pp 121–128. Koottatep, T., Polprasert, C., “Role of plant uptake on nitrogen removal in constructed wetlands located in tropics”, Water Science and Technology , Vol. 36, No. 12, 1997, pp 1-8. Kantawanichkul, S., Supreeya Kladprasert, S., Brix, H., “Treatment of high-strength wastewater in tropical vertical flow constructed wetlands planted with Typha angustifolia and Cyperus involucratu ”, Ecological engineering , Vol. 35, 2009, pp 238–247. Juwarkar. A., Oke, B., Juwarkar, A., and Patnaik, S.M., Domestic wastewater treatment through constraucted wetland in India, Water Science & Technology, Vol. 32, No. 3, 1995, pp. 291-294. Vymazal, J., “Removal of nutrients in various types of constructed wetlands”, Science of Total Environment , Vol. 380, 2007, pp 48-65. Lin, Y., Jing, S., Wang, T., and Lee, D., “Effects of macrophytes and external carbon sources on nitrate removal from ground water in constructed wetlands”, Environmental Pollution , Vol. 119, 2002, pp 413-420. Dendene, M.A., Rolland, T., Tremolieres, M., Cariener, R., “Effect of ammonium ions on the net photosynthesis of three species of Eldoea ”, Aquatic Botany , Vol. 46, 1993, pp 301-315.

Jinadasa, K.B.S.N., Tanaka, N., Sasikala, S., Werellagama, D.R.I.B., Mowjood, M.I.M. and Ng, W.J., “Impact of harvesting on constructed wetlands performance – a comparison between Scirpus grossus and Typha angustifolia ” J Environ Sci Health A Tox Hazard Subst Environ Eng, Vol. 43, No. 6, 2008, pp 664-671.

Volume II

Key Note Address

A STRATEGIC FRAMEWORK FOR AN INTEGRATED WATER MANAGEMENT AND WATER SUPPLY CHAIN FOR AN URBAN CENTRE: WATERSHEDS, RESERVOIRS, AND WATER SUPPLY NETWORK – SECURITY & RISK.

Prof. Tan Soon Keat, Nanyang Technological University, Singapore

VISION This proposal envisions a management system for surface water and delivery of potable water to the residents in an urban centre such as Singapore. We envision a framework for water management and water supply chain to support information, reporting and management system within 3 years, through 4 Tracks founded on a backbone of software modelling and decision support tools. These 4 Tracks are: management of watershed and harvesting of water; management of a multi-function and multi-reservoir system; risk management and security of the water distribution system; and water quality monitoring and instrumentation.

THE APPROACH The various expertises in areas such as operation, planning, contingency response, public education, modelling, simulation, monitoring, research, scenario analysis, design and assessments exist in Singapore, in the various government agencies and departments, research institutions and consultant companies. There are also pockets of research and development work on water quality monitoring, sensor development, contaminant and nutrient removal from the waterways, as well as catchment managements. These various efforts and expertises could be stitched together to provide a seamless web of information flow and decision support for the managers. This framework could be jointly developed with champion government agency (EWI) in consultation with water authorities and agencies, and leverage on the international experience through our resource people in the university and research network, and specialist consultants, and carried out in a programme based on 4 Tracks which share certain commonality and yet are distinct in their own right. The common area lies in the development of the information and management system which is founded in the strong backbone of software tools including data management, information management, modelling and simulation, system analysis as well as expert-system-like

49 decision support systems. Figure 2 shows the technology road map for the 4 Tracks of this programme 1.

1 All 4 Tracks require strong support on instrumentation and sensor – sensing network, control, communication and software interface. While the team is fully capable of developing software tools and interfaces, specialist inputs in the design of sensors and sensing network will be required. It is recognised that proprietary development of sensor and sensing network, protocol, etc. will distract attention from the focus and objective of the programme. While electronics and mechanical engineering know how may be needed at times, expertises and specialists help could be sourced, when the need arises, to develop the hardware and software to the special needs. As much as is possible, the hardware development will be restricted to integration of off-the shelf items.

Figure 1: A diagrammatic sketch of the water chains and elements in an urban water environment.

Track 1: Management of watershed and harvesting of water This Track plans to establish the land use and catchment characteristics of a number of catchment, and model the rainfall-runoff-water quality relationship, to provide the input for design of water storage facilities, the transfer system, and the necessary preliminary process of particle separation, and removal of nutrients and contaminants. Several catchment types will be considered: nature reserve, cluster dwelling, public housing estate, industrial estate 2. Certain catchment types will be selected and sensor network installed to provide the flow and water quality data. Selection of the water quality parameter will be guided by the catchment and land use characteristics. This part of the work will be carried out with the intention not to repeat or duplicate reported or on-going catchment studies. The state of arts of the rainfall-runoff modelling is well-established. This study aims to develop the complimentary part, i.e. water quality modelling, and in particular, address the issue of non-point source pollutants, the distribution, entrainment and transport characteristics in surface runoff, the drainage channel and waterway. While genetic algorithm or artificial neural network approach have been adopted by contemporary researchers, this research team proposes to adopt a hybrid approach which hinges heavily on physically based conceptual model initially and progressively driven by data supplied through on-line sensor networks which are either installed by this research team or obtained through communication interfaces from other sensor networks. The rainfall-runoff-water quality modelling process yields the quantity and quality of rainwater from the catchment. While it is not the main objective of this framework, rainwater harvesting, “capture-treatment-storage” will be investigated and innovative scheme developed to achieve harvested water of reasonable water quality. Rainwater capturing ancillary with incorporated sediment separation designs (vegetation or certain landscaping features), be it through innovative hydraulic flow design, hydraulic filter pack, vegetated channels/waterways, or infiltration galleries would be considered. The hydraulic filter pack, vegetation and wet-land-like features would be specially design taking into consideration land scarcity and the need to treat large amount of rainwater generated over a short duration. The team view the large area of sand-filled reclaimed land in Tuas, the west coast, East coast and Changi areas potential storage aquifers. The benefit is two folds – displacing saline water as well as providing fresh ground water storage in the soil pores. Storage of water in storm drains and possibly through hollow/floating structures below deck (of port/wharves/jetties), or floating inflatable storage devices in the nearshore area would be investigated. New floating structures (e.g. honeycomb concrete structures) could be used to store water below deck while supporting other uses on the deck could be an option.

2 Petro-chemcial and shipyards are not considered at this stage.

The rainwater “capture-treatment-storage” study provides various plausible alternatives to the management of watershed The information of rainwater quantity and quality, and that of the harvested water, will be captured and form part of the database to support the integrated management system. Track 2: Management of multi-function and multi-reservoir system Characterisation of the reservoirs, both in terms of effective volume, water quality and their function as an element of a storm drainage system is the first goal of this Track. Then the strategy of an utilisation matrix of the reservoirs, in terms of the regulation of the water level, buffer volume in anticipation of heavy storms, and health and water safety standards for various recreational activities, will be developed. Modelling of the reservoir 3 will also include, in addition to quantity and quality requirement for abstraction for water treatment, the necessary conditions to support the eco-system quality in the reservoir. The experience of consultants and operators are of tremendous values here. The modelling technique will be based on a combination of budget-accounting, routing and optimisation, with a strong emphasis on decision support in response to external influence such as anticipated rainfall, demands and ad hoc request to support certain recreational activity or water use. Modelling tools as an important interfacing platform to integrate the watershed, on the upstream end and through abstraction of water to supply the water treatment plants at the other end. Coupled with this is an emerging requirement to enhance the quality of life through providing bio-diversity, and such healthy ecosystems of a reservoir also may serve as an escape from urban life. The management system and functionalities will be extended to include multiple reservoirs, which together would provide shared capacity and volume for an efficient and seamless multi-reservoir operation. Expert-system-like decision support system will also be developed to incorporate in the system database, invaluable experience of the consultants and engineers from the various agencies and authorities. Information of the volume, capacity, water quality, and water safety advisory will form the database for the integrated management system. This Track also has the special need to provide “predictive” capability to “anticipate” future demands and potential quantity and quality of water. Historical data (rainfall, temperature, water use patterns, etc) and statistical techniques would be incorporated to form the decision support tools for the management system.

3Eutrophication and other reservoir circulation modelling will not be investigated in details. Provision will be made to allow for information and data set that will facilitate modelling and reporting of relevant parameters. Similarly provision will be made for including in the database, characteristics and performance of devices for enhancing reservoir circulation and relevant water quality parameter.

Track 3: Risk management and security of water distribution system This Track aims to extend the framework to include a holistic, life-cycle- management approach to integrate these processes with the objective of providing an established risk assessment and management framework and system assurance model for the water distribution system in Singapore. The design of a real-time water quality sensor and communication network, as well as sensor location, analysis of sensor signals, contamination source identification, and response and containment will be developed. Damage in one of these facilities such as pipe leakage, due to, for example ground movement, corrosion of structure or pipe, water contamination by chemical or biological factors (waterborne disease), and pipe breakage, can bring about a major setback to the water supply system 4. Risk assessment and management methodology aimed at determining the level of provision of drinking water supplies and to describe sources, causes and consequences of a risk, as well as evaluation of risks and consequent measures to mitigate the potential risks on a water supply distribution system will also be developed. An emergency/contingency plan will also be designed and feed into the centralised management system which provides an online monitoring and information system for the integrity of the infra-structure and assurance of the water quality/safety of the water transported in the system.

Track 4: Water quality monitoring and instrumentation Instrumentation and development of strategies for sensing the water environment are important so as to capture the water quality variables without losing fidelity of distribution of the sensed parameters in the environment. A sensor network will be necessary to provide detailed spatial information as well as providing a communication network for the transmission of sensed data and control between the controller and the sensors. With emerging contaminant issues and realisation of the significance of trace chemicals, pharmaceuticals, and hormones, new sensors which are bio-based, fluorescence, photonic-based or gene-group detection probes will be developed. Statistical data mining methods will be employed to infer temporal and spatial data patterns and to facilitate effective water quality monitoring and resources management. A field campaign on a selected water body will be carried out to characterise the water quality of relevant parameters in the bed and bank sediment, in addition to the water body at large. Other parameters indicating the bio-diversity and ecological health of the water body will also be included in the campaign. This field campaign will be carried out in close liaison with other research groups, to widen the scope and coverage (both spatial and temporal) of the field work, and maximise returns of the research resources and efforts. The pooled data will be channelled to the integrated management system both as a database as well as a bench mark reference to set the water standard, and provide advisory to the manager and the public when and where negative deviation in water quality has

4 Pressure transient induced by mechanical system and external excitation is provided for in the database structure but detailed investigation will not be carried out in this programme.

54 been detected. Relevant environment policy and issues will be explored and provision made in the database to enhance the capability of the management system.

Framework and strategy for an integrated management and on-line information While the development of the framework begins immediately at the individual component level, the integration process will be developed progressively to build the framework, database and functionality of the integrated management system. The science and knowledge generated and model/information developed will be integrated to support dissemination of information, reporting and management on the same common platform. The framework will be based on an open structure that will allow flexibility for building interfaces to communicate with other data groups and operations. The system will also provide the basic framework for the development and incorporation of a decision making supporting system and scenario analysis.

ANTICIPATED OUTCOMES The information and management of the selected individual elements of the water supply chain, i.e. watershed, reservoir and selected surface water body, and a reticulation network could be established within 2 years. Also in place are communication interfaces for the incorporation of data and information from other sources. The individual management systems could be further developed and integrated to form the framework of an integrated management system by the third year. We anticipated a working framework that be available to demonstrate the capability of the system and the benefits it has on the establishment of a common database, integration of information from various relevant sources, sharing and dissemination of information, reporting, providing advisory and management of the raw water resources and water supply network. The system will also have in place an initial framework to support data mining capability to perform data consistency, risk analysis, contingency response and scenario testing.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

Framework & strategy: An Integrated Water Management and Water Supply Cha in for an Urban Centre: 36 MONTHS 36 Watersheds, Reservoirs, and Water Supply Network – Security & Risk

watershed development of 30 MONTHS 30 information, development of reservoir on-line WQ and surface and sub-surface water WQ reporting and information, reporting and structural health information system management management system risk assessment , reporting network system demonstration scenario analysis field station and contingency modeling of interfacing and 24 MONTHS 24 response Modeling of water quality and routing, transport, modeling scenarios, water transport in surface and subsurface storage, operation reservoir as an abstraction and monitoring - water water quality integral element multi-functions structural integrity of watershed and management of and maintenance, water supply to reservoir response to treatment plants 18 MONTHS 18 rainwater critical response ground movement development of field campaign: collection raw of water supply sensor / sensing monitoring of bed rainfall runoff water harvesting network to hazard network and bank modeling water ecological storage systems / functional analysis sediment, water quality modeling modeling of innovative storage reservoir water quality and reservoir as a system quality standards sensor ecological health

12 MONTHS 12 habitat water supply development for of raw water water supply network - physical / bodies; Communication, hardware and software interface software and hardware Communication, interface software and hardware Communication, innovative interface software and hardware Communication, interface software and hardware Communication, network engineering, chemical and bio- water quality approach towards land use modeling of Reservoir infrastructure - environment and sensors / analytics testing removal of water quality reservoir - water characterization identification of information development of protocols for trace particles, nutrient catchment relevant data storage and environment and critical elements relevant data and information system and information sensor / sensing chemicals

6 MONTHS 6 and contaminants characterization distribution water quality from other from other strategy from raw water sources, sources, Track 1: Management of Watershed and including other Track 2: Management of multi-function Track 3: Risk management and security of including other Track 4: Water quality monitoring and harvesting of rainwater utilities, multi-reservoir system water distribution system utilities, instrumentation government government agencies, and agencies, and other R & D other R & D Projects Projects

Figure 1: The programme roadmap showing the 4 Tracks, and a unified development of the management system during the last 9 months. Note: The field work, demonstration basin, sensor development and sensor network development will be conducted in liaison with other research groups to extend the scope and coverage of the research study and to optimise the research resources and returns of the effort expanded. Where it is relevant, interfaces would be developed to integrate data and information from various sources into the common database and information system.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

SUSTAINABLE MANAGEMENT OF URBAN LAKES ENVIRONMENT AND ECOSYSTEM: A CASE STUDY ON LAKES OF UDAIPUR

Sonal Gupta

Project Associate, Indian Environmental Society, New Delhi, India

ABSTRACT Water is one of the most important elements required for life on earth. The natural water bodies are vital for the survival of human civilizations. Among the water bodies, lakes are important and contribute about 87% of all the fresh water on the earth surface. Inhabitants living in and around a lake depend on it for water, food, recreation, tourism etc. There is no single term used for “Lakes” in India. The lakes are generally of many types– Natural, Manmade and Ephemeral. Many lakes in India are categorized as wetlands by Ramsar Covention. Udaipur city is located in the south west part of Rajasthan State. It is the sixth largest city of Rajasthan. Due to lakes and water bodies, it is called the “City of lakes or Venice of east”. It is one of the most beautiful cities in the world. Udaipur city is unique in its own way. Being situated in drier part of India, the city constitutes hilly soil and unmatchable water resources. The city holds great ecological importance. Lakes of Udaipur are the lifeline of city as they not only add a picture perfect beauty to the city but also act as a boon for tourism that helps the local people. However, these lakes are in immense threat of degradation as a result of catchment degradation, encroachments, urbanization and waste disposal etc. Due socio-economic importance of these lakes, it is a timely need to conserve the lakes and their catchments mainly through awareness building among school children and the residents of the city.

1.0 INTRODUCTION Udaipur is situated in the south - west of the State of Rajasthan in India: - the “Land of the Raj's’’ - Kings - at the bottom of the mountain range Aravali in a valley 577m above the sea level. It is a city, a Municipal Council and the administrative headquarters of the Udaipur district. Udaipur is located at 24°35’ N 73°41’ E/ 24.58°N 73.68°E / 24.58; 73.68. The location of the city in India and State of Rajasthan is given in Figure 1. It has an average elevation of 598.00 meters. The climate of Udaipur is tropical, with the temperature ranging between 42.3°C 28.8°C summers. Winters are mild with the maximum temperature rising to 28.8°C and the minimum dipping to 2.5°C. Usually climate is pleasant around the year. According to the 2001 India census, Udaipur has a population of 3.89 lac listing the city among the most populated cities of Rajasthan. Males constitute 53 % of the total population of the city 57

Urban lake monitoring and management: Proceedings of a n international symposium, 18 May 2012, Peradeniya, Sri Lanka.

while females account for 47 %. Udaipur is a beautiful city surrounded by the Aravalli hills and many major lakes such as Pichola, Fatehsagar, Rang sagar, Swaroop sagar and the smaller Dudh Talai. The Udipur lakes have been the source of income for a significant number of populations of the city.

Figure 1: Location of Udaipur Initially Udaipur city had faced water scarcity as it is located in the semi- arid region. Number of lakes and reservoirs had been constructed by the rulers to fulfill the water demands in the city. Local people used to take water from these lakes for their daily needs. These lakes are important aquatic ecosy stem. The lakes of Udaipur are prime sites for the bird watchers as they are the habitat for many migratory birds and resident birds as well. But at the same time, they are very fragile and prone to ecological destruction. Over the years, many construction s have been taken place around the lakes making huge pressure on the lake ecosystems. Subsequently, these lake have become places for household and industrial waste discharges. The catchment 58

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

areas of lakes are facing serious problems of deforestation and overgrazing by livestock. With the habitat loss and due to excessive pollution in the lakes, the nesting and breeding sites for the birds are being adversely affected. Noise pollution has become an emerging problem near the shores of the lakes due to excessive movement of vehicles around the lakes. Within this background, this paper deals with the problems of urban lakes in Udaipur, environmental issues in their catchment areas, sources of pollution, their degradation and ways and means of maintaining the quality of lakes for future use. Environmental situation of Udaipur Though outwardly Udaipur looks serene with its lakes and gardens, environmentally it is heading towards disaster. Factors such as poor awareness among people, heavy tourist flow, human activities such as deforestation, siltation, lack of public participation etc are threatening the wetland ecosystems of the city. This in turn put greater impact on the lake biodiversity. Most of the hotels (more than 100 in numbers) along with around 6000 residential houses accommodating more than 33000 populations are located on the lake slopes. Around 100 thousand populations are residing in the vicinity of lakes. Recently observed environmental problems of the area include releases of solid and liquid waste into the lakes. The waste collected from the roads, dirt thrown from the houses, debris of the dilapidated houses, and dead animals are thrown on the banks of the lakes. Most importantly, 73 Ghats (used for bathing and washing), 42 garbage spots, 45 drain spots and around 118 open defecation spots are located in the periphery of the lakes; all of which release a shocking quantity of pollutants into the lakes. The movement of hundreds of boats inside the lake contribute significantly to lake pollution making them unfavourable for the existence of wetland biodiversity. Indiscriminate deforestation in the hills surrounding Udaipur and in the adjoining forests of Mewar region wash down tonnes of silt into the lakes during monsoons every year. The silts flow in to the lakes reduce the water holding capacity. It has been estimated that the capacity of two major lakes of the city such as Pichola is getting reduced every year by 0.93 per cent and that of Fatehsagar by 1.16 per cent. Engineering calculations estimated that, the life in terms of dead storage of the lake is hardly 28 years and in terms of gross storage, the life of Pichola is estimated at 97 years and of Fatehsagar at 72 years, by which time these lakes will be completely filled by silt. Urbanization around the lake has also degraded lake water quality, which is risky to health of the people who are dependent on the lake for their water supply requirements. Increase in nutrient level is also taking place on account of leaching from agricultural activity in the marginal agricultural lands around 59

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

the lake periphery. These are some of the reasons attributed for lake degradation. The pollution of the lakes has not only affected the health of the people of Udaipur. It has also practically wiped out several species of fish. The bigger carps are fast disappearing, leaving only minor carps, minnows and puntius. The situation is indicative of the slow poisoning of the people of Udaipur. The city of Udaipur is also famous for its marble mining and production. Hundreds of Marble mining and producing companies are working in the Industrial belt of Udaipur city. These industries are generating tons of Marble slurry which affects the local atmosphere, lake water, agriculture land and causing respiratory diseases among animals including human.

2.0 LAKES OF UDAIPUR CITY The Udaipur lake system, arising out of the river Berach (Banas Basin) and its tributaries, is an integral component of the upper Berach basin .The upper Berach basin is a part of the Gangetic river system, wherein the river Berach meets Ganga through the rivers Banas, Chambal & Yamuna. More than three- fourth portion of the region is a part of the oldest mountain ranges of Aravalis from where different tributaries of the Berach River are originated. The general slope of the basin is eastward. However from Madar to Udaisagar it is in southeasterly direction. Pichola Lake Pichola Lake is one of the most beautiful and is located in the heart of the city. It is the oldest and one of the largest lakes of Udaipur. The lake was built by Pichhu Banjara. It derives its name from the village of 'Pichholi'. Within the lake, there is a famous hotel named “City Palace”. Lake Pichola comprises several islands that accompany the calm waters of the lake. The world- renowned Lake Palace is perfectly located on the Jag Island of this tranquil lake. The Sisarma stream, a tributary of the Kotra River, drains a catchment of 55 km 2 from the Aravalli Mountains and contributes to the flows in the lake. It accounts for a total water body area around 6.96 sq. Kilometres and has gross, live and dead capacities of 483,318 and 165meft respectively. Its gauge height above and below sill level is 3.35 and 5.2 metres. The lake has a maximum depth of 10.5 metres (Rathore and Sukhadia undated) During drought conditions because of lower rainfall & degradation of the catchment the lake becomes dry. During the years 1998 to July 2005 the lakes of Udaipur were reportedly dry.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

Fateh Sagar Lake Fateh Sagar Lake is located in the north of Lake Pichola; the lake was built in 1678 by Maharana Jai Singh. The Lake got its name from Maharana Fateh 0 Singh, who later made additions to it. The Lake is situated at 24 35’ N. lat. and 0 73 37’E. Longitude at 578 metres altitude (m.s.l.) in the north western side of the city. This pear shaped and medium sized lake was constructed by Rana Jai Singh in 1678 A.D. It was renovated in 1889 A.D. by Maharana Fateh Singh. The lake is 720 m long, about 100 m wide and rises nearly 40 m from the ground level towards east. Fatehsagar lake stretches 2.6 kms in north-south and 1.8 kms in east-west directions, covering a total water spread of nearly 4.00 sq.km and maximum depth of 13.4 metres. It commands a total catchment area of about 41 sq.km. Its gross, live and dead capacity are 427.60, 247.60 respectively and 180-mcft water, evidently lower than that of Pichhola. JaisamandLake Jaisamand Lake is renowned for being the second largest artificial lake in Asia. Located at a distance of 48 kms from the city of Udaipur, Jaisamand Lake is also known as Dhebar. In 1685, Maharana Jai Singh built this lake while making a dam on the Gomti River. The Jaisamand Lake Catchment is located in the Udaipur district of Rajasthan. Located in a semi-arid region, Jaisamand Lake is a main water supply for the city of Udaipur. The Lake was originally created in the early 18 th century to enhance the conservation of wildlife. Jaisamand Lake with a gross capacity of 414.6 Mm 3 and live storage of 296.14 Mm 3, is Asia’s second largest artificial water storage reservoir. The gross basin area up to the Jaisamand dam site is 1787 km2. The lake is also a prime source of water for the city of Udaipur located at a distance of about 52 km from the lake. Jaisamand is a prominent medium irrigation project with a cultivable command area of 160 km 2 downstream of the lake. The Jaisamand Lake Catchment is an area of low hills formed of eroded hard-rock comprising part of the Aravalli Hills Range. Ground elevations in the basin range from 300 m to 650 m above mean sea level approximately. Rainfall (mean 650.3 mm) occurs during months of June – September (94%) typically as several intense storms and light showers spread over a period of about 20-30 days. Rivers typically flow only for a few months following the rains.(http://nih.ernet.in) Rajsamand Lake Rajsamand Lake is one of the five popular lakes of Udaipur. Located 66 km in the north of Udaipur, Rajsamand Lake lies between Rajnagar and Kankroli. The lake is also known by the name of Rajsamudra Lake in Rajasthan. Rajsamand Lake was built by Maharana Raj Singh in 1660.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

Udai Sagar Lake Udai Sagar Lake is another striking lake that falls under the category of five lakes of Udaipur. Udaisagar Lake is located at a distance of about 13 km in the east of Udaipur. The construction of this lake was started in 1559 by Maharana Udai Singh and got completed in 1565. Rang Sagar Lake It was constructed in 1668. It is 1.03 km long and 245 m wide. It has a maximum depth of 7 m. It acts as a link channel between Pichhola Lake towards south and Swaroop Sagar and Fateh Sagar in the north. Its water holding capacity is 1000 mcft. Swaroop Sagar Lake- It is a pear shaped lake which was constructed by Swaroop Sagar in the year 1678. Its gross capacity is 427 mcft. Its live and dead capacities are 247 mcft and 180 mcft respectively. Its total area is 4.00 km 2 and has a maximum depth of 13.4 m. It was constructed by the Maharana Swaroop Singhji. It is interconnected with Rang Sagar Lake and Fateh Sagar Lake. . Dudh/ Doodh Talai Doodh Talai is a small lake that adores the south-east direction of Pichola Lake. Located in the southern side of Shiv Niwas Palace, Dudh Talai contributes to the waters of Lake Pichola. This stream adds to the picturesque triangle in the company of Pichola on one side, Doodh Talai on the second and M.L. Verma Garden on the third. Goverdhan Sagar This Lake is situated to the south of Pichhola. Its gross catchment area is 2.5 km 2 and its live capacity is 9 mcft. It is connected with Lake Pichhola through a link channel. Jiyan Sagar (Badi Ka Talab) Jiyan Sagar is another striking lake, located in the village of Badi. Built by Maharana Raj Singh, Jiyan Sagar was built to deal with the problem of famine in the area. The lake was named after Jana Devi, mother of Raj Singh. Jiyan Sagar is also known as Badi Ka Talab. It sprawls in an area of 155 km 2 and the embankment of the lake extends to the length of 180 meters and width of 18 meters.

3.0 AVIFAUNA OF URBAN LAKES OF UDAIPUR In total, 242 species of birds belonging to 68 families were recorded from the urban habitats of Udaipur during the period of five years from July 2004 to Jun 2009. Out of the total, 140 bird species representing 42 families were

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

recorded from the terrestrial habitats whereas 102 bird species representing 26 families were recorded from aquatic habitats. Five species of global importance, namely, Indian White-backed Vulture; Long-billed Vulture; Green Munia from terrestrial habitats and Spot-billed Pelican; Indian Skimmer from aquatic habitats, 6 recorded in the past from the study area were also enlisted in the checklist but not sighted during the course of study (Mehra et al., undated).

4.0 ECOLOGICAL DEGRADATION OF UDAIPUR LAKES Habitat Destruction- A lot of residential areas have come up around the lakes and even some people have acclaimed the submerged areas for residential purposes. The discharge from these colonies is directly polluting the lakes destructing the aquatic habitates. Water pollution – The city and downstream lakes are heavily polluted and are facing an imminent danger of irreparable degeneration. The physical setting of the Udaipur city enhances the flow of pollutants into the Lakes. Most of the hotels along with 6000 residential houses accommodating 33000 populations are located on the lake slopes. The people living in the walled city use the lakes for bathing and sanitary facilities. Apart from bathing, vehicles are also washed in the lakes. The people perform their religious rituals and ablutions at the lakeside. Muslims and Hindus submerge their religious creations (idols) into the lake. The pollution of the lakes has not only affected the health of the people of Udaipur, it has also practically wiped out several species of fish. 4.1 Degradation of lakes and catchment areas The lakes and reservoirs are in varying degrees of environmental degradation. The degradation is due to encroachments, eutrophication and silt. There has been a quantum jump in population during the last century without corresponding expansion of civic facilities resulting in lakes and reservoirs becoming sinks for contaminants. Catchments areas are sources of water for the lakes and also for the underground reservoirs. Continuous degradation of these catchment areas has resulted in depletion of useful flora and fauna of the region. The catchment area damage also results soil erosion which in turn causes deposition of silt in the lakes. It also disturbs the whole ecosystem of the area. The vegetative cover in almost entire catchment areas is very poor which is not sufficient to meet the food, fuel, fodder and other requirements of the human as well as livestock population of the area. The high velocity runoff coming from barren hills and degrades areas have also been severely damaging the arable lands situated in the valleys and lower reaches. The catchment areas are highly degrades and ground water has depleted to alarming level.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

4.2 Present needs The lakes of Udaipur are of great importance and providing immense benefits to the people especially tourist flow which in turn provide income to many families in the city. The problem of catchment area degradation, lake water quality degradation and silt deposition should be taken care urgently. The activities planned in this purpose should be participatory and local people should be motivated for taking care of the lakes. Various target groups such as students and teachers, youth, boat owners/drivers, fishermen, local voluntary organizations etc should be trained and their capacity should be built. The target groups should be provided with the information about the importance of the lakes for human being. People should be aware regarding the impact of their activities on the lakes. Awareness generation and information dissemination can sensitize the local people and they will come forward to protect the lakes through their changed behaviour and participatory nature. The NGOs should be sensitized, motivated and encouraged to take the task of awareness generation, information dissemination, capacity building and training of various stakeholders. 4.3 Lake conservation efforts Indian Environmental Society in association with the Ramsar Centre, Japan is implementing a project entitled “Contributing to the CBD_COP 11 through WETLAND CLUB activities on Biodiversity Conservation”. The project is supported by the Japan funds for Global Environment (JFGE) and the project duration is for three years starting from April, 2011. The main objective of the project is to promote the conservation of wetlands to conserve the biodiversity. The project is involving target groups like students, teachers, community people including community youths, local voluntary organizations and planning to build their capacity through training and demonstration. The interesting part of the project is to set up WETLAND CLUBS in schools. A responsible teacher will be the in-charge of the club and school students along with the educated youths from the school neighborhood community will be the club members. The aim is to transfer the scientific messages from school to community through students and community youths. The club members will be provided with training on water quality monitoring and will be encouraged to collect the water quality data of the Lakes from time to time. All the necessary materials like books, scientific instruments etc will be provided to each wetland clubs and the club members can use the same to collect the data. Various awareness programs will be organized in the schools and community to aware and sensitize the target group. A competitive exhibition on Wetland and Biodiversity is planned to will be organized in which the wetland 64

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clubs will participate and the best performers will be awarded with the prizes. The resource materials like information packets, posters, activity manual etc. will be developed every year and distributed among the target groups During the first year of the project, five wetland clubs were set up in 5 different schools. The club members were trained and motivated to collect the data on lake water quality, Lake Biodiversity, local issues like improper waste deposition, marble mining and slurry generation/ deposition.

5.0 REFERENCES Rathore, N.S. and Sukhadia M.L. undated.University College of Social Science and Humanities, University, Udaipur. Mehra, S.P., Mehra, S. and Sharma, K.K. undated.Urban Avifaunal Biodiversity in context of Udaipur, Rajasthan, India, independent.academia.edu, Accessed on 02/04/2012).

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

INTEGRATED LENTIC AND LOTIC BASIN MANAGEMENT (IL 2BM) FOR URBAN LAKES: WATER GOVERNANCE FOR SUSTAINABILITY AND LIVELIHOOD OF PEOPLE

Sandeep Joshi

Shrishti Eco-Research Institute (SERI),Pune – 411 030. INDIA.

ABSTRACT Ever expanding urban sprawls are on the naturally inherited lands of water bodies like streams, rivers (lotic – hydrodynamic water bodies) and lakes (lentic – hydrostatic water bodies). Generally development takes place in the catchment of recurrent, perennial source of fresh water. Unplanned growth of population and industrialization is causing quantitative and qualitative deficits of water availability in the catchment of rivers and lakes in the modernized urban areas. Urban growth directs sharing of the water amongst the human population and ecological biodiversity disproportionately without acknowledging the ecosystem services provided by the lentic and lotic water bodies to the urban systems. Governance has primary mandate and objective of looking after equitable opportunities for everybody, welfare and protection of the population and natural resources in the geographical area under its jurisdiction. Time taken for comprehension, capacity building and awareness of governing systems based on environmental emergencies has resulted in unprecedented scaling up of numerous global, regional and local environmental problems. Governance - representation of the people can be strengthened for the existence of lentic and lotic water bodies in the urban areas – considering the ecological properties and services of aquatic ecosystems for the livelihood. In this paper, the attempt has made to evolve the axioms, principles of Government’s Environmental Accountability and Responsibility (GEAR) for the sustainable lake management through the adaption of six pillar approach of Integrated Lentic and Lotic Basin Management (IL 2BM) with a comparative study of some Asian lakes and their catchments in different geo-climatic conditions. The attempt has been made to evaluate the action plans for sustainable management of lakes involving various stakeholders, civil society initiatives, scientific inputs, professional services and regulatory mechanisms. Keywords:Urban lifestyle, aquatic systems, GEAR, ecosystem approach, (IL 2BM)

1.0INTRODUCTION Lakes are generally defined as hydrostatic, lentic, stagnated natural, manmade or ephemeral waterbodies including ponds, backwaters of dams and reservoirs (Nakamura, Masahisa and Rast, Walter, 2011; Reddy, M. S. & Char, N. V. V. 2006). Non-availability of inclusive historical documented references to the existence of lakes, scientific data about its catchment and water quality lead to the present trivial status of lakes in different geoclimatic regions of India. Every district of India had thousands of small lakes, ponds and tanks integrated with day to day life of people. These were either naturally collected waters in a depression from the surrounding land, meandering nature of rivers 67

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or by landslide or volcanic action or man – made reservoirs by damming the rivers and streams. Urbanization (UN, 2005) is on its peak in developing countries putting pressure on natural water and land reso urces. Ever-expanding cities are engulfing water bodies like lakes, ponds and streams and encroaching on their flood plains by constructing retaining walls, channelizing them to increase residential, commercial or agricultural constructed areas or making t hem dumping yards for liquid and solid wastes (Kodarkar, M. S., 1995; Wikipedia on Kandy Lake; Joshi, Sandeep, 2011a). Solutions to issues of urban lakes such as encroachment by construction industry or modern farming practices, discharges of wastes direct ly into the lakes, lack of will and knowledge among administrators and politicians, ineffective use of legal tools, no availability of Suitably Applicable and Affordable Technologies (SAAT) and systems for control of lake pollution and water quality manage ment, awareness among the masses can be derived from six pillar approach of policy, institutions, information, participation, technology and finances (Pokharel, Shailendra, and Nakamura, Masahisa, 2010). In addition to these six pillars, there can be one more central pillar which holding the sustainability thought and process is the spirituality in some of developing countries. It is shown as in following fig. 1.

Figure: 1 Pillars of Sustainable management of streams, rivers (lotic) and lakes (lentic) systems

2.0 LAKES AND CLIMATE CHANGE Nowadays, urban lakes and lean -flowing, sewage carrying rivers have become waste receiving and processing units generating huge quantities of methane gas – a greenhouse gas. Global warming and climate change are today’s key issues of sustainable urban development. Greenhouse gas emissions from freshwater lakes and reservoirs and their contribution to the increase of 68

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

greenhouse gases in the atmosphere are the core of worldwide debate. Studies show that 3-10 times more greenhouse gases are produced by newly formed reservoirs than from natural lakes of the same size (www.lakescientist.com) or the lakes which receive urban wastes as in case of Ujjani reservoir in Mashasrashtra State of India generating 50,000 tons (estimated based on waste ingress) of methane gas annually (Ghole, V. S., 2011a).

3.0 WASTE DUMPING IN THE RIVERS AND LAKES AND WATER QUALITY ISSUES In most parts of the world, freshwater resources are overstrained and overburdened by population growth. Industrial wastes, sewage and agricultural runoffs overload rivers and lakes with toxic chemicals, wastes and nutrients, consequently poisoning water resources and supplies. Two billion tons of human and animal waste and industrial pollution are dumped into waterways every day around the world (UNEP, 2010). Sulfur and nitrogen oxides are spewed into the atmosphere from industry and power plants, where they fall back to Earth as acidified rain thousands of miles away from their point of origin. These toxins are finding their way into plants and animals from the water causing severe ecological toxicity at various trophic levels. In the developing cities, it is estimated that more than 90 percent of sewage is discharged directly into rivers, lakes, and coastal waters without treatment of any kind (www.nyop.unep.org; www.unep.or.jp). Over two billion people are expected to live in metropolises, mega-cities of developing countries leading to aggravation of problems of river and lake pollution. In most of the developing countries governments are fighting to eliminate fecal contamination from rivers and lakes which are sources of drinking water for poor communities. Many city administrations are failed to alleviate the dumping of raw sewage and garbage into rivers and water supply canals, or to control the mounting of solid wastes near the banks of rivers and lakes from residential and industrial areas. Point sources of pollution are identifiable such as discharge pipes, concretized sewerage line where they can be easily measured and controlled. While non-point sources of water pollution, earlier known as "diffuse" sources pollution, emanating from expansive group of human activities for which release pollutants with no obvious point of entry into receiving water-bodies. Non-point sources of pollution are much more difficult to identify measure and control than point sources. Non-point source pollutants, irrespective of source, are transported overland and through the soil by rainwater and finally reach the groundwater, wetlands, rivers and lakes and, to oceans in the form of sediment and chemical loads carried by rivers.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

4.0 ENVIRONMENTAL GOVERNANCE Concept of environmental governance integrates knowledge of livelihood activities with moral responsibility to act carefully in regards to the environment quality on a local, regional and global scale. Sense of environmental responsibility by stating that the improvement of democratic practices, transparency and accountability of government institutions, along with civil participation in decision making, are strongly related factors to the objectives of the protection of the environment and social and economic justice. The role of different stakeholders is well-explained in the inter-sectoral plain – axis model in fig. 2. In this model, it is depicted that governments playing role of facilitator and regulator try to provide products and services through the chain of private actors and trade facilitators to the public at large who is at receiver end. While using technologies, engineering and economic plans intend to use electronics as a growth monitoring tool and yardstick while neglecting the ecology – source of all resources.

Figure 2: Inter-sectoral plain - axis model of interaction between human environment and ecology Natural resources and the environment should be considered as a local or regional or global public good – commons resources. This means that everyone can benefit from the atmosphere, climate and biodiversity etc. This planetary dimension requires a collective management approach by recognizing that every person has the right to live in an environment adequate to his or health and well-being. On the other hand, he has a duty, both individually, and in association with others, to protect and improve the environment for the benefit of present and future generations. Citizens with government are to be entitled to participate in decision-making and accessing to the justice in environmental matters.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

Environmental governance - a thought in political ecology with environmental policy can define the elements needed to achieve sustainability locally, regionally and globally. All human activities - social, cultural, economic and political - should be managed implicitly as the subsets of the environmental set ups and land – water, lentic - lotic ecosystems. Governance includes not only local or provincial or federal governments, but also business and industrial communities and civil societies accentuating the whole system management. Considering the diverse nature of dynamic forces, environmental governance generally has a foundation of alternative systems of governing, decision - making, for example watershed based management. Integrated Lentic-Lotic Basin Management (IL 2BM) is a model of environmental governance where the entire catchment of the lake and its rivers, tributaries and streams are considered as one unit. Therefore, it helps in finding the ways and means of decision making at agreed convergence point of governments and people. It is shown in fig. 3.

Figure 3: Collaborative framework of water resources management – Saturn model Environmental governance involves the inclusion of the following key issues to ensure sustainable management of lakes - • Environmental values and economics of ecosystem services of lakes • Environmental policy inclusive of objectives, targets, strategy • Acknowledging environmental responsibility for capacity building, technology development and communication • Scientific monitoring of limnological processes of lakes with lake audits 71

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• Ensuring environmental performance of the actions taken on the basis of key performance indicators (such as stress, process and status indicators), eco-efficiency, and compliance

5.0 CASE STUDY 1: UDAIPUR’S ECOLOGICAL RESTORATION OF AHAR RIVER AND IMPROVEMENT OF UDAISAGAR LAKE Water is an unalienable right for every human being. All levels of water supply management are necessary. Ahar River and Udaisagar Lake of Udaipur India were highly polluted till December 2009 due to city drains and industrial discharges about 150 Million Litres per Day (MLD) (Kodarkar, Mohan and Joshi, Sandeep, 2010). The river and lake lost their ecological health, biodiversity and use for routine human activities in the rurban and rural areas downstream of Udaipur. Turtles – bio- indicator - deserted the polluted river as there was no suitable water quality for their survival. This project was supported by Udaipur Chamber of Commerce and Industries (UCCI). Therefore, in this project all pillars of IL 2BM governance policy, institutions, knowledge, participation, technology and finances worked together to make it successfully restore the river and lake within a period of 3 months. The action plan of ecological restoration of 150 MLD river – a non- monsoon – dry weather flow involved - • Initiation and co-ordination by Jheel Sanrakshan Samiti (Lake Protection Group), a local non-government organization with and ILBM conceptual support by International Lake Environment Committee (ILEC) Foundation, Japan and Indian Association of Aquatic Biologists (IAAB), India. • Technological support and guidance by experts of Shrishti Eco- Research Institute of Pune, India. Use of in-situ green bridge technology for water purification and revival of ecological health of river • Support from all stakeholders including City Management, relevant government agencies like Forest Department, Irrigation Department and Agriculture Department. • Spiritual and social invocation of the masses to support the river restoration programme • Strong financial support by the industrial group Six green bridges (horizontal eco-filtration) in-situ ecological treatment systems were developed in the course of river in a distance of about 1.6 km. Green bridges were seeded with mixed bacterial cultures helpful in treating

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

organic and inorganic wastes and local green plants were grown to support the activity of microorganisms symbiotically. This resulted in - • Multifold increase in Dissolved Oxygen from 0 to 10.4 mg/L • Reduction in ecological toxicity neared to zero • Exponential increase in phytoplankton and zooplankton • 250 times fish growth • The entire river stretch got its life again with return of turtles, snakes and birds

6.0 CASE STUDY 2: RESTORATION OF BUDDHA STREAM OF SATLUJ RIVER RECEIVING WASTEWATER FROM LUDHIANA’S URBAN AND INDUSTRIAL AREAS It’s a successful government – a major stakeholder’s decision-making process of adoption of innovative ecotechnological treatment systems through the consultative meetings of Planning Commission, Government of India, Ministry of Environment and Forests, Central Government, National River Conservation Directorate (NRCD), Central Pollution Control Board (CPCB), Punjab Government, Punjab Pollution Control Board (PPCB) and Ludhiana Municipal Corporation (LMC) means involvement of all local, regional and national governments for a common cause of restoring the ecological health of highly polluted stream of dry weather flow of 600 MLD (Joshi, Sandeep, 2011b; www.moef.nic.in). It has strengthened the Government’s Environmental Accountability and Responsibility (GEAR) with strong technology pillar having support from public at large who are dependent on waterbody for their activities.

7.0 CONCLUSION So, the water governance involves the political, social, economic and administrative systems as well as livelihood processes with business and societal wisdom and traditional knowledge that are in place, which directly or indirectly affect the use, development and management of water resources. Importantly, it emphasizes that water sector is a part of broader ecological, social, political and economic developments.

8.0 REFERENCES Ghole, VS, Patwardhan Ashok and Joshi, Sandeep (2011) Impact analysis of agriculture and agro-industries on Ujjani Reservoir, Maharashtra, India. 14 th World Conference organized by River Systems Institute, Texas University anmd Interenational Lake Environment Committee Foundation (ILEC), Japan, Nov. 1- 5, 2011.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

http://en.wikipedia.org/wiki/Kandy_Lake http://www.lakescientist.com/learn-about-lakes/lakes-climate-change/lakes-and- greenhouse-gases.html http://www.nyo.unep.org/action/11.htm http://www.unep.or.jp/ietc/issues/freshwater.asp Joshi, Sandeep (2011a) Protection of urban lakes for city’s environment quality and livability. In proceedings of International Conference on people, places and opportunities towards sustainable cities – 2030.Organized by AIILSG, UCLG- ASPAC. Pg. 75 – 91. Joshi, Sandeep (2011b) Detailed Project Report of Buddha Nala Ecological and Ecological Restoration (Buddha NEER) submitted to Government of India. UNEP Report (2010) Sick water.The central role of wastewater management in sustainable development.Ed. Emily Corcoran. Kodarkar, Mohan and Joshi, Sandeep (2010) ILBM impact story – ecological restoration of highly polluted stretch of Ahar river, Udaipur and ecological improvement of Udaipsagar lake, Rajasthan, India. Presented in Final review meeting and international symposium of a project entitled “Intengrated Lake Basin Management (ILBM), Basin Governance, Challenges and Prospects”, Nov. 2- 7, 2010.International Lake Environment Committee (ILEC) Foundation, Headquarters, Kusatsu, Japan. Kodarkar, M. S. (1995) Conservation of lakes, case study of five lakes in & around Hyderabad, Andhra Pradesh. India. Publ. 3. Indian Association of Aquatic Biologists (IAAB), Hyderabad. Nakamura, Masahisa, and Rast, Walter (2011) Development of ILBM Platform Process. Published by RCSE, Shiga University, and International Lake Environment Committee Foundation, Japan.Pp. 4. Pokharel, Shailendra and Nakamura, Masahisa (2010) Integrated Lake Basin Manmagement (ILBM) for the sustainable conservation of Himalayan lakes of Nepal.Wetland Conservation Publication Series no. 2.National Lake Conservation Development Committee (NLCDC), Ministry of Tourism and Civil Aviation, Government of Nepal. Pp. 15 – 22. Reddy, M. S. & Char, N. V. V. (2006) Management of Lakes in India. Lakes & Reservoirs: Research & Management 11(4), 227-237. United Nations, DESA, Population Division. World Urbanization Prospects: The 2005 Revision. www.moef.nic.in URL: http://moef.nic.in/downloads/public-information/press-note- launch-of-bio-remediation-project-ludhiana.pdf

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

SEASONAL VARIATION OF WATER QUALITY AND PLANKTON OF LAKE GREGORY, SRI LANKA

1* 2 1 1 M. B. U. Perera , S. K. Yatigammana , S. A. Kulasooriya , N.P. Athukorala

1Institute of Fundamental Studies, Hantana road, Kandy. 2 Department of Zoology, Faculty of science, University of Peradeniya.

ABSTRACT A shallow, small man made reservoir located within a high altitudinal populated city in Sri Lanka was studied to assess the effects of seasonal changes on water quality and plankton dynamics. Data were collected from four sites during wet and dry seasons at three months interval for a period of one year, March 2011 to March 2012. From the measured environmental variables, turbidity, ammonia-N, Total Phosphorus and Chlorophyl a showed elevated levels during the wet season (October – December) and conductivity and alkalinity were high during the dry season (February and April). Diversity of plankton was more during the wet season (34 species) than the dry season (24 species). However the study reveals that the concentration of plankton was high during the dry season. In addition, relative abundance data showed that some species of cyanobacteria (e.g. Cylindrospermopsis raciborskii ) abundant during the wet season when the reservoir records high nutrient temperature , turbidity and pH values whereas diatoms (e.g. Aulacoseira granulata ) more abundant during the dry season. Thus the seasonal environmental changes are likely to affect the water quality which may have influence the changes of community composition of planktons in the study reservoir. Keywords: Lake Gregory; plankton; water quality; Cylindrospermopsis raciborskii; Aulacoseira granulata ; Sri Lanka.

1.0 INTRODUCTION The total annual precipitation falling on Sri Lanka is ~1,370 million m 3 out of which only ~31% is discharged to the sea by 103 main rivers (Arumugam, 1969). However, this large amount of precipitation is not equally distributed over the country; some areas are consistently wet, whereas others show marked seasonality and arid conditions (Ranatunga, 1992). The Wet Zone covers only 17,000 km2, and the central highlands are also located in this region whereas the Intermediate and Dry zones cover 48,000 km 2 which is more than two thirds of the total land area of the country. The Wet Zone receives a mean annual rainfall (MARF) of more than 2m, which occurs throughout the year from the southwest-, northeast-, and convectional inter-monsoons. In this zone, precipitation is much greater than the estimated evaporation rate of 1.5 m year -1 (Kumarasinghe , 1997). In contrast, precipitation is highly seasonal in the Intermediate and Dry zones, and evaporation greatly exceeds precipitation (Kumarasinghe, 1997). These regions get precipitation mainly from the northeast monsoon which delivers a MARF of between 1.5 and 2 m to the Intermediate Zone, and 1 to 1.5 m to the Dry Zone (Costa & de Silva, 1995). 75

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However evapotranspiration in the Dry Zone has been estimated to be as high as 2.1 m/year (Kumarasinghe , 1997). Due to the seasonal nature of precipitation, and the fact that evaporation exceeds precipitation over ~75% of the country, reservoirs have been constructed since the ancient times for irrigation and domestic use. In addition some reservoirs have been constructed as ornamental lakes especially within the wet zone urban areas (Fernando, 1979). As a result of widespread reservoir construction in Sri Lanka more than 4% of the total land area is covered by manmade lakes (Fernando, 1993). Many Sri Lankan reservoirs are thought to be in danger from eutrophication and pollution due to increasing human activities (Costa and de Silva, 1995). In addition the recent global climatic changes are also appear to affect these systems through the changes in the timing and persistence of the monsoons, and therefore susceptible to significant variations in water quantity and quality. Reservoirs located within the densely populated cities are more susceptible to human induced pollution and as a result Colombo Baire Lake is experiencing hyper eutrophic conditions with more than 600 µg/l of total phosphorus (TP) (Yatigammana, 2004). Among the other ornamental reservoirs, Lake Gregory is also a man made fresh water reservoir located in a high altitudinal city, Nuwara- Eliya, Sri Lanka. The reservoir and the catchment receive rainfall distributed throughout the year and however monthly averages range from minimum 70 mm in March to maximum 245 mm in October. Thus there is a marked variation in precipitation in some months. Mean monthly temperature is almost constant over the year ranging from 14 ⁰C to 17 ⁰C. (IUCN Sri Lanka and Central Environmental Authority, 2006). Thus the reservoir is located in an area having wet-montane type climate. Nanu oya is the main stream that feeds the reservoir and the catchment mainly includes agricultural lands where heavy agrochemicals are being used. In addition tourism related activities also practiced within the catchment and also in some parts of the reservoir bed. Thus the reservoir is subjected to many stresses of natural and anthropogenic in origin. The current agricultural practices in the catchment of the reservoir and the lack of an integrated approach to natural resources management coupled with insufficient infrastructure and inadequate maintenance of land use have resulted in the degradation of the surrounding environment which will affect the health of the reservoir. Some of the issues are identified as serious environmental problems, such as soil erosion, landslides, flooding, siltation, filling up of the reservoir bed, eutrophication, depletion of water quality, loss of biodiversity, deforestation and the degradation of the visual environment (IUCN Sri Lanka and Central Environmental Authority, 2006). As many of these environmental problems are climate and weather related identification and the ranking of the environmental problems can be done through, direct measurements and also monitoring plans. In addition indirect measurements of environmental 76

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conditions can be obtained through information revealed by life histories of biological indicators in aquatic systems. Among the biological indicators, planktons are identified as useful indicator organisms that can be used in environmental predictions to infer limnolological changes such as eutrophication, salinisation and lake-level fluctuations both qualitatively (Whiteside 1970; Hann et al. 1994) and quantitatively (Verschuren et al. 2000; Lotter et al. 1998; Bos and Cumming, 2003). In addition, these organisms have been used to understand complex changes in food webs, such as competition and predation (Bos 2000). Furthermore, planktons have been used to infer changes in habitat, including changes in the abundance of macrophytes, temperature and oxygen (Hofmann,1996). Habitat alteration can directly or indirectly be related to environmental changes such as climate (Verschuren et al. 2000) and pollution (Broderson et al. 1998; Lotter et al. 1998). Therefore, changes in plankton community structure can be used to better understand the environmental changes in lakes and reservoirs. However before use them as environmental indicators it is necessary to see if the aquatic systems are vulnerable to environmental changes and if the systems support adequate number of potential plankton species before use them as environmental indicators. Thus the current study was undertaken in order to assess the impact of seasons on water quality and plankton dynamics in Lake Gregory located in a densely populated tourism oriented city of Sri Lanka.

2.0 MATERIALS AND METHODS 2.1.Reservoir characteristics Lake Gregory is located within the limits of the Nuwara Eliya city in the central hills of Sri Lanka. It lies between latitude 6 o 57 ′ 35.05 ′′ - 6o 57 ′ 08.04 ′′ N and longitude 80 o 46 ′ 29.18 ′′ – 80 o 6′ 46.71 ′′ E. The surface area of the reservoir is approximately 40ha. Maximum depth is about 17feet. The reservoir and the catchment are underlain by highly crystalline charnokitic gneiss of pre- cambrian age. The soils of the watershed area and the catchement are mainly of the red yellow podzolic type and are strongly weathered and heavily leached. Due to heavy leaching, the soil remains acidic. Because of the high altitude the climate is cooler than the lowlands of Sri Lanka, with a mean annual temperature of 16 ⁰C. However the temperature changes and sometimes it can be as low as 3 ⁰C. Rainfall is distributed almost throughout the year with the, monthly averages ranging from 70 mm in March to 245 mm in October.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

Figure 1: The study site showing the four sampling sites A,B,C and D. 2.2 Sample collection and analysis Collection of water samples for the analysis of chemical variables from the study reservoir was undertaken between for 12 months, from March 2011 to March 2012, to cover both wet and dry seasons. Because the winds were typically high during the day, most of the sampling and field measurements were carried out either during the morning or early evening. Water samples from a depth of ~ 0.5 m were obtained from four sampling sites (site A, site B, site C and site D- Fig. 1) for laboratory analyses of nutrients, alkalinity, dissolved oxygen, Chl. a. and sulphate. The samples were collected in 500-ml polyethylene bottles that were rinsed with lake water prior to sampling. Preservation of water samples followed the APHA (American Public Health Association standard methods for examination of water and wastewater, 18 th edition). The samples were stored in a cooler and transported to the Institute of Fundamental Studies (IFS) Kandy, Sri Lanka within 24 hrs of obtaining the samples. Onsite measurements of temperature, salinity, conductivity, specific conductance were taken at 0.5-m of the reservoir with a field instrument (Thermo Orion- Model 105). Field measurements of pH were obtained using Orion ® Model 230A portable pH meter, using a two-point calibration, which encompassed the measured value. The Secchi depth of each reservoir was measured using a 22-cm diameter Secchi disk.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

Measurements of chemical and physical variables Prior to analyses, samples were stored in a refrigerator at the IFS. Chemical analyses of the water samples were normally completed following their receipt, using the standard procedures as outlined by the American Public Health Association (APHA, 1992). All chemical analysis were undertaken at the IFS. Information on lake surface area, watershed area and reservoir age were obtained from the Department of Irrigation (Sri Lanka) (Arumugam, 1969). The number of years since the last restoration for each of the reservoirs was used as an estimate of the age of each reservoir. Plankton sampling Plankton samples were collected from the selected sites using plankton nets of pore size 10 µm and 50 µm. Samples were preserved in acid Lugol’s iodine for phytoplankton analysis and in formalin for zooplankton analysis. The identification of species was done using a research microscope (OLYMPUS CX 31) and identification keys prepared by Desikachary (1959), Abeywickrama (1979), Fernando (1990) and Yatigammana ( 2004).

3.0 RESULTS 3.1. Physical and chemical conditions According to the results, Lake Gregory is eutrophic in both seasons having total phosphorus level more than 30 µg/l. (Table 1). However, there is a marked variation of TP during the wet season having hypereutrophic conditions. In addition recorded chlorophyll a values also indicate that the primary production is higher during the wet season. Same pattern was observed for nitrite –N, and ammonia-N within the study sites of the reservoir. The elevated levels of dissolved oxygen were observed during the dry season. The conductivity values indicate a clear dilution effect during the rainy season. Among the measured environmental variables alkalinity values show that the reservoir is rich in acid neutralizing capacity during the dry season than the wet season. Table 1.Seasonal variation in the physic-chemical parameters of the Lake Gregory. Parameters Dry season Wet season Water temperature ( ⁰C) 18 20.1 Dissolve oxygen (mg/l) 8.54 7.01 Turbidity (NTU) 14.99 34.9 pH 8.98 9.05 Conductivity (µs) 119 107

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Alkalinity-total (mg/l) 48.82 43.93 Nitrite –N (ppb) 13.06 27.51 Nitrate -N (ppm) 1.3 0.01 Ammonia- N (ppb) 38.81 145.05 T-Phosphorous (ppb) 60.75 186.76 D-Phosphorous (ppb) 5.19 8.26 Sulphate (mg/l) 1.45 3.1 Chl.-a (mg/l) 58.21 136.17 Secchi (m) 0.75 0.5

3.2 Planktons Diversity of plankton were more during the wet season (36 species) than the dry season (26 species). However the study reveals that the absolute abundance of both zooplankton and phytoplankton were high during the dry season. In addition, relative abundance data showed that some species of cyanobacteria (e.g. Cylindrospermopsis raciborskii ) abundant during the wet season when the reservoir records high nutrient values whereas diatoms are abundant during the dry season Table 2. Absolute and relative abundance of planktons recorded in two seasons in Lake Gregory Relative Absolute Species abundance (%) abundance wet dry wet dry Phytoplankton Cyanophyceae Anabaena sp. 0.2 0.12 10 10 Anabaena circinalis 0.1 0 5 0 Aphanizomenon sp. 0.4 0.06 20 10 Coeleospharium sp. 1.34 0.19 65 15 Cylindrospermopsis raciborskii 75.4 0 3650 0 Limnothrix sp. 1.44 7.85 70 615 Leptolyngbya sp. 1.13 0.12 55 10 Gomphosphaeria sp. 0.2 0.12 10 10 Microcystis sp. 0.1 0.19 5 15 Microcystisaeruginosa 0.2 0.25 10 20 Microcystis incerta 0.2 0.31 10 25 Merismopedia punctata 0.3 1.78 15 120

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Planktothrix sp. 3.2 17.24 155 1185 Raphidiopsis curvata 0.1 0.12 5 10 Rivularia sp. 0.1 0.06 5 5 Synechocystis sp. 0.2 0 10 0 Chlorophyceae Pediastrum tetras 0.1 0.19 5 15 Scenedesmus quadricauda 0.2 2.74 10 215 Scenedesmus acuminatus 0.2 0.89 10 70 Staurastrum sp. 0.2 0.06 10 5 Staurastrum serata 0.3 0.57 15 45 Bacillariophyceae Aulacoseira granulata 0.5 52.36 25 4100 Cymbella sp. 0.1 0.06 5 5 Fragillaria sp. 0.2 0 10 0 Fragillaria crotonensis 14.75 15 515 1175 Navicula sp. 0.5 0 25 0 Euglenophyceae Phacus sp. 0.1 0.19 5 15 Trachelomonas sp. 0.4 0 20 0 Dinophyceae Peidinium sp. 0.8 0.76 40 60 Zooplankton Copepods Calanoid copepods 0.1 0 5 0 Rotifers Tricocerca sp. 0.1 0 5 0 Polyarthra sp. 0.2 0.06 10 0 Notholca sp. 0.2 0 0 0 Larval forms Nauplius larva 0.1 0 5 0 Protozoans unidentified sp. 0.2 0.06 10 5

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

Wet season Dry season No of Individuals No ml /

Absolute abundance

Figure 2: Variation of dominant taxa in dry and wet seasons in Lake Gregory

4.0 DISCUSSION Physicochemical changes influence the plankton communities in the aquatic systems, both qualitatively and quantitatively. Limnological factors such as temperature, pH salinity controlled the plankton ecotype, and the nutrients control the biomass is a well known factor worldwide. According to the results obtained, environmental factors prevailing in the wet season appear to support high diversity of planktons than the dry season. There were 29 species of phytoplankton and 5 species of zooplankton recorded in the wet season and 23 species of phytoplankton and one species of zooplankton recorded during the dry season. However concentration of plankton was high during the dry season. In addition, relative abundance data showed that some species of cyanobacteria (e.g. Cylindrospermopsis raciborskii ) dominate the system during the wet season and could not find a single filament during the dry season. According to Berger et al. (2006), C. raciborskii biomasses were mainly related to high temperature and water column stability where as Marcina et al., 2008 suggest that C. raciborskii population dynamics were influenced by water temperature, high pH values and low euphotic zone values. In our study also during the wet season when the water temperature, tubidity and pH values were high, unusually large filaments of C. raciborskii were observed at high abundance. However, according to Liyange & Magana-Arachchi (2012), C . raciborskii is the dominant phytoplankton in many of the Dry zone reservoirs especially in the Anuradhapula district. However, Briand et al. (2002), explain that C. raciborskii is a highly adaptable species live under wide variety of environmental conditions and thus difficult to predict the occurrence of proliferation. For example, although C. raciborskii is known to prefer thermally stratified warm tropical waters (McGregor and Fabbro,2000) some studies have

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shown that they prefer to colonize in shallow temperate waters with highly variable temperature and climatic conditions (Padisák 1997). However in temperate climates they are highly abundant in warm climatic conditions and may not even appear under cool a climate which is highly comparable with our study (Padisák 1997). During the dry season when the reservoir experience high conductivity and low water temperature diatom species Aulacoseira granulate was highly abundant with relative abundance more than 50%. This species is known to respond to both physical and chemical limnological variables such as flow condition, turbidity and silica concentrations (Hotzel & Croome,1996) During the high floods and low silica concentrations A. granulate tend to reduce in number which also could be compared with our study as they show drastic reduction in the wet season. Past studies have demonstrated that nutrients were the main factors determining the concentrations of chlorophyll a and plankton communities in aquatic systems in Sri Lanka (Yatigammana, 2004). In Lake Gregory the highest chlorophyll a concentrations were recorded during the wet season and could be due to high nutrient input related to the high soil erosion from nearby agricultural and economic crop plantations where intense fertilizers are being used. These results also could be justified by the positive relationship observed between the nutrient concentrations and the Chl-a (Table 1). However, not all planktons show same response patterns to different nutrients. For example some phytoplankton species such as Microsistis prefer phosphorus limited conditions (Machida et al, 2008) and some species prefer N limited conditions (Perera et al., 2012). In addition other environmental variables could also be more important determining factor of the plankton communities. According to Wasmund (2007) some species such as Aphanizomenon sp. and Nodularia spumigena respond to salinity changes. Further, unlike an ecologically balance lentic system where positive relationship between zooplankton and phytoplankton occur, the Lake Gregory shows a weak relationship between the two groups. This could be due to highly variable nature of limnological condition of the reservoir. In addition during the dry season diversity and abundance of zooplankton was less and could be due to the less availability of principle food source of the group especially nanoplankton (McCauley & Kalff, 2011). Thus the dynamics of plankton species observed under two different seasons of the Lake Gregory could be directly related to seasonal environmental conditions as well as environmental changes induced by the variation of seasons. However as we have measured only few environmental variables due to the lack of available resources, we may have missed some important determining factor that could explain plankton dynamics of the study reservoir.

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

5.0 REFERENCES Abeywickrama, B. A., 1979. The genera of the freshwater algae of Sri Lanka.Part 1 – UNESCO Man and the Biosphere National Committee for Sri Lanka, Spec. Publ. 6. Nat. Sc. Council Sri Lanka, Colombo: 1-103p. APHA. 1992. Standard methods for the examination of water and wastewater. 18 th edition, America Public Health Association, Washington Arumugam, S.,1969. Water Resources of Ceylon its Utilization and Development. A Water Resources Board Publications, Colombo, 415 pp. Berger C, Ba N, Gugger M, Bouvy M, Rusconi F, Couté A, Troussellier M and C. Bernard (2006). Seasonal dynamics and toxicity of Cylindrospermopsis raciborskii in Lake Guiers (Senegal, West Africa). Microbiol.col.. 57(3):355-66. Bos, D.G. and B.F. Cumming, 2003. Sedimentary cladoceran remains and their relationship to nutrients and other limnological variables in 53 lakes from British Columbia, Canada. Can. J. Fish.Aquat. Sci. 60: 1179-1189. Bos, D.G., 2000. Sedimentary cladoceran remains, a key to interpreting past changes in nutrients and trophic interactions. Ph.D. thesis, Queen's University, Kingston, Ontario, Canada.190 pp. Briand, J.F., C. Robillot, C. Quiblier-Lloberas, J.F. Humbert, and A. Coute, 2002. Environmental context of Cylindrospermopsis raciborskii (cyanobacteria) blooms in a shallow pond in France. Water Research 36: 3183-3192. Broderson, K.P., M.C.Whiteside and C. Lindegaard, 1998.Reconstruction of trophic state in Danish lakes using subfossil chydorid (Cladocera) assemblages.Can. J. Fish.Aquat. Sci. 55: 1093-1103. Costa, H.H. and P.K. De Silva, 1995. Limnological research and training in Sri Lanka: state of the art and future needs. In (eds. Wetzel, R.G. & B. Gopal) Limnology of developing countries 1: 63-103. Desikachary, T. V., 1959. Cyanophyta. Indian council of Agricultural research, New Delhi: 1- 686p. Fernando, A.D.N., 1979. Major ancient irrigation works of Sri Lanka. J. Roy. Asiatic Society (Sri Lanka Branch) 22: 1-24. Fernando, C. H., 1990. The fresh water invertebrate fauna of Sri Lanka. In: Zoological survey of Sri Lanka: Fresh water fauna and fisheries of Sri Lanka. Fernando, C.H. (ed.) Natural Resources, Energy & Science Authority of Sri Lanka, Colombo: 1 – 444p. Hann, B., P.R. Leavitt and P.S.S. Chang, 1994. Cladocera community response to Experimental eutrophication in Lake 227 as recorded in laminated sediments. Can. J. Fish.Aquat. Sci. 51: 2312-2321. Hofmann, W., 1996.Empirical relationships between cladoceran fauna and trophic state in thirteen northern German lakes: analysis of surficial sediments.Hydrobiologia, 318:3, 195-201.

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Hotzel. G & R. Croome, 1996. Population dynamics of Aulacoseira granulata (EHR.)(Bacillariophyceae, Centrales), the dominant alga in the Murray River, Australia.Archiv für Hydrobiologie Y. 1996, 136 (2),191-215. IUCN Sri Lanka and Central Environmental Authority. 2006. National Wetland Directory of Sri Lanka. The Central Environmental Authority (CEA), The World Conservation Union (IUCN) and the International Water Management Institute (IWMI), Colombo, Sri Lanka. 1-34p. Kumarakulasinghe, S. A., 1997. Monthly Temperature Trends in South India and Sri Lanka. An overview of the Global Historical Climatology Network temperature data base, Bulletin of the American Meteorological Society, submitted. Lotter, A., H.J.B. Birks, W. Hofmann and A. Marchetto, 1998. Modern diatom, cladocera, chironomid, and chrysophyte cyst assemblages as quantitative indicators for the reconstruction of past environmental conditions in the Alps. II. Nutrients. J. Paleolim.19: 443-463. Magana-arachchi, D., Wanigatunge, R. and Liyanage, M. 2011. Molecular characterization of cyanobacterial diversity in Lake Gregory, Sri Lanka. Chinese Journal of Oceanology and Limnology: Vol. 29 No.4, p. 898-904. Marcina C. P. Gemelgo, Célia L. Sant’Anna, Andréa Tuccie, Heloiza and R. Barbosa, 2008.Population dynamics of Cylindrospermopsis raciborskii (Woloszynska) Seenayya & Subba Raju, a Cyanobacteria toxic species, in water supply reservoirs in São Paulo, Brazil McCauley, E and, J. Kalff, 2011.Empirical relationships between phytoplankton and zooplankton Biomass in Lakes. Canadian Journal of Fisheries and Aquatic Sciences , 1981, 38(4): 458-463, 10.1139/f81-063 McGregor, G.B and L.D. Fabbro, 2000. Dominance of Cylindrospermopsis raciborskii (Nostocales, Cyanoprokaryota) in Queensland tropical and subtropical reservoirs: Implications for monitoring and management . Lakes & Reservoirs: Research and Management 5: 195-205. Natural Resources Energy and Science Authority Sri Lanka, 1991.Natural resources of Sri Lanka. (Report) 280 pp. Perera, M.B.U., Yatigammana S.K. and S.A. Kulasooriya, 2012.Prevalence of toxigenic cyanobacteia in different climatic zones of Srl Lanka.Symposium Proceedings: International Symposium on Water Quality and Human Health: Challenges Ahead, PGIS, Peradeniya, Sri Lanka, pp.31-32. Pidasak, J., 1997. Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju, an expanding highly adaptive cyanobacterium: worldwide distribution and review of its ecology. Arch. Hydrobiol. Suppl. 107: 563-593. Ranatunga, D.M., 1992. The orthogonal structure on monsoon rainfall variation over Sri Lanka. Theoretical and Applied Climatology 46: 109-114. Verschuren, D., J. Tibby, K. Sabbe and N. Roberts, 2000. Effects of depth, salinity, and substrate on the invertebrate community of a fluctuating tropical lake. Ecology. 81: 164-182.

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Wasmund, N., 1997. Occurrence of cyanobacterial blooms in the baltic sea in relation to environmental conditions. Int. Revue ges.Hydrobiol.Hydrogr., 82: 169–184. Whiteside, M.C., 1970. Danish chydorid Cladocera: modern ecology and core studies. Ecol.Monogr. 40:79-118 Yatigammana, S. 2004. Development and application of Paleoecological Approaches to Study the Impacts of Anthropogenic Activities Reservoirs in Sri Lanka. Ph.D Thesis , Queen’s University, Kingston, Ontarrio, Canada, 178.

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WHY PROACTIVE WATER MANAGEMENT IS IMPORTANT FOR URBAN LAKES? THE CASE OF KANDY LAKE

E.I.L 1Silva,and Herath Manthritilake 2

1Water Resource Science and Technology Consultants, Ragama, Sri Lanka 2International Water Management Institute, Battaramulla, Sri Lanka

ABSTRACT In May 1999, Microcystisaeruginosa - a non-nitrogen fixing cyanobacteriaformed a noxious bloom inKandy Lake,creating a huge socio-political issue. Although attempts were made to achieve an early recovery, thecyanobacterium remained in high densities asthe trophic state of the Lake changed from eutrophic under wet weather to hypereutrophic in the dry weather.M. aeruginosa, which has a doubling time of about twenty hours flush out with the outflow, beingmassively grazed by tilapia and face with natural death. Consequently, the blooming is being regulated under natural circumstances. The outbreakof cyanobacteria bloom is directly related withphysicochemical variables including nutrients. Since nitrogen species are abundant in this urban water body, the concentration of soluble reactive phosphate is vital for the rapid growth of cyanobacterium. The water input (precipitation, surface runoff, drainage and subsurface inflow of groundwater) and output (evaporation, seepage and outflow as output) balancehas direct bearings onphosphorous loading into the Lake. Since the last outbreak, a number of top-down and bottom-up approaches were proposed to cut- off phosphorus loading into the Lake.Most of them were not implemented due to various reasons. If water balance is not maintained effectively, existing seasonally hyper-eutrophic state may lead to an outbreak of cyanobateria bloom again. Therefore, continuous monitoring of waterinput and output parameters together with retention time,nutrient concentrationand cyanobacteria biomass in terms of colony counts is imperative as a management tool.

1.0 INTRODUCTION Emergence of harmfulcyanobacterial blooms resulting from galloping eutrophication, are spreading globally and threatened the sustainability of freshwater ecosystems. Increasingly, non-nitrogen -fixing cyanobacteria (e.g ., Microcystis ) dominate such blooms in most cases, indicating that both excessive nitrogen (N) and phosphorus (P) loads may be responsible for their proliferation. Traditionally, watershed nutrient management efforts to control these blooms have focused on reducing P inputs. However, N loading has increased dramatically in many urban watersheds with poor sanitary facilities, promoting blooms of non-N2 fixers, and altering lake nutrient budget and cycling characteristics. We examined this proliferating water quality issues in Kandy Lake, a typical urban lake located in the heart of Kandy, the hill capital of Sri Lanka. This shallow water body which shows eutrophic-hypereutrophic 87

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alteration under wet and dry weather conditions (Silva 2005 ) was collapsed in May 1999 by an outbreak of Microcystisaeruginosa bloom following a sudden draw-down (Silva, 2003). Certain strains of M. aeruginosa thrive in Kandy Lake was toxigenic under stresses conditions (Jayatissa et al. 2006 ) and patches of algal scums are not uncommon in the edges of the inflow area although bottom sediment from there were dredged out with translocation of a fair number of tilapia fish from the Lake.Theemergence of bloom with surface scum impair the surrounding urban environment of the Lake which is located adjoining the world famous Buddhist temple where the sacred tooth relic of Lord Buddha is placed. Of the four urban lakes in the country (Silva, 2012), Kandy Lake provides several goods and services to the resident and visiting communities while contributing to the economy of the city directly or indirectly. Certainly, it has no high pragmatic value, whereas inspirational, scholarly and tacit values are incredible. Pragmatic value or direct income generation from Kandy Lake mainly lies on tourism activities, since the Lake is not being used as a source of drinking water and prohibited from fishing. Scholarly values extend the knowledge on urban lake ecosystems and scholarly manifestations often contribute to pragmatic values. For an example, better understanding of science of urban lakes can improve management, potentially increasing commercial fisheries, drinking water extraction and tourism revenues. Nevertheless the Lake environment is being creatively used for productive activities such as photography, landscape painting , film locations, literature, songs, other artistic expressions etc., which are inspirational values. Almost unspoken values, called tacit values such as enjoyment of scenery and landscape features, jogging, and bird watching are difficult to quantify. Indeed, Kandy Lake isa fortune for the city and an asset of the country. Careful management of resources of this nature bring the health and wealth for the city. However, nutrient enrichment canlead to blooms of noxious algae which presenttaste and odour problems and under the worstsituations, prohibit recreational use.It is therefore, necessary to launch regular monitoring and comprehensive studies as the need arises as prerequisites for maintain them in a sustainable manner for future uses. On this line we attempt here to highlight the importance of regular monitoring of hydrology of the Lake as a management tool for regulating sudden blooming of this vulnerable urban water body.

2.0 MATERIALS AND METHODS Kandy Lake is an ornamental water body, located in the hill capital, Kandy, the second largest city in the country. Being situated in the heart of Kandy city enhanced with a paramount scenic value, adjacent to world famous Buddhist Temple DhaladaMaligawa where sacred tooth relic of Lord Buddha is placed, the Lake has become one of the largest tourist attractions of the country. The Lake was built by the last King of the Singhalese monarchy (1789-1815), Sri 88

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VikremaRajasimghe between 1810 and 1812 using forced labour to enhance the panoramic beauty of the Royal Palace Complex and surrounding temples. Kandy, the symbolic holy city of the country is presently renowned as one of the key heritage cities in the world because of its cultural legacy, archeological importance and aesthetic value. The Lake was in existence since its construction as a perennial water body and the water from the Lake had been used to augment the city water supply during the mid seventies for a short period. Since it is located adjoining the most esteemed religious center, fishing and bathing are prohibited and at present the Lake water is neither use for irrigation nor other domestic purposes. People make pleasure trips by motorboats, which are being operated for several years. A chronic cyanobacteria species ( M.aeruginosa ), emerged as a bloom and formed into a thick scum in Kandy lake with the onset of the southwest monsoon in May 1999. The outbreak of this bloom became a major socio-political issue because it is assumed that Kandy Lake is a national asset. Some important features of the Lake are given in Table 1. Long term data collected from Kandy Lake from 1998 to 2008 on phosphorous and nitrogen concentrations, chlorophyll-a contents, were analyzed with rainfall data to identify whether there are specific patterns of distribution and relationship between parameters. Nitrogen and phosphorous concentrations and discharge volumes of twelve storm water inlets determined monthly in 2004 were also incorporated in the analysis to identify the pattern of N and P loading into the Lake. In most cases, species composition and population densities of phytoplankton were maintained as a data bank. Data collected on physicochemical characteristics, total and coliform bacteria and zooplankton were not incorporated in this analysis. Species composition and fish population density of the Lake was estimated by National Aquatic Resources Research and Development Agency (NARA) as an outcome of fish translocation trails. Hydrological data of the Lake were not available to incorporate into mass balance calculations. Therefore analysis was primarily restricted to empirical demonstration rather than accurate quantitative values. Table 1: Basic morphological characteristics and some limnological features of Kandy Lake

Parameter Morphology and limnology Type Manmade Climatic zone wet Coordinates’ 7⁰ 18´ 29.98” N; 80 ⁰ 38´ 22.89” E Elevation (m) 519 Area (ha) 18 Watershed (km 2) 2.64 89

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Maximum depth (m) 12.5 Perimeter (km) 2.6 Shoreline Development 2.15 Volume (Mm 3) @ spill level 0.3839 Fetch (km) 1.03 heading 118.31 degrees Uses recreation Values pragmatic, scholarly, inspirational, tacit Trophic status Eutrophic-hypereutrophic alteration Dominant cyanobacteria Microcystisaeruginosa Scholarly publications 24

3.0 RESULTS AND DISCUSSION Kandy experiences a year round rainfall with a prominent peak during the second inter monsoon (October-November) which brings about 40 per cent of the annual rainfall which is about 1500 mm. Although the rainfall is high during the second inter-monsoon, the southwest monsoon (May-September) brings more rainfall than the northeast monsoon (December-February). The months of Jan, Feb, March bring the lowest inflows to the Lake. If the Lake catchment receives 1500 mm annual rainfall the Lake receives 2.6 Mm 3 of water which is 6.8 times of the Lake volume. In other words 6.8 times of water volume flows through the Lake while carrying algal biomass and other dissolved and suspendedmatter. The amount of storm water drains into the Lake may be relatively high due to the imperviousness watershed and the steep gradient of thecatchment landscape. With the diminishing tree cover, the runoff -rainfall ratio is rising. The inflow patterns are gradually turned into intermittent flash flows with the buildup area increase.Surface sewerage flows aresent turned to underground flowsthrough onsite disposal systems with high concentrations of pollutants. A fair amount of untreated sewage and other waste still drain into the lake from five schools with large student populations, several nursing homes, tourist hotels of different capacities and numerous residential houses on hill slopes.Relationships between the degree of catchmenturbanization – as assessed by catchment imperviousness– and ecological degradation of urban water have emerged in recent years (May et al. 1997).Climate change will have serious implications on inflows of the lake. The volumes of flash flows shall increase, with increased lag between such flows. Surface temperature to, is predicted to be rising. The masonry weir located at the south-west corner – spill is the only outlet.The adjacent sluice is usually kept closed. Seepage to downstream and the evaporation from the surface are the two critical outflows from the Lake during drier months.Table 2 shows the estimated averagevalues algal biomass

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(in terms of chl-a) and N and P loss from the Lake per year. Accordingly, Kandy Lake lose 130 kg of chl-a and 1300 kg and 260 kg of N and P respectively. When 130 kg of chl-a is converted into algal biomass the amount will be substantial but it cannot say that whole biomass is cyanobacteria since planktonic algae even in a hyper-eutrophic waterbody is a species assemblage. Table 3 shows the annual load of total phosphorous and nitrogen (as nitrate and ammonia nitrogen) from twelve inlets of Kandy Lake. Table2: Estimated values of average algal biomass and N and P loss from the Lake per year Constituent Annual average Flow through Loss load (mg m -3) volume (Mm 3) (kg y -1) Chlorophyll-a 50 2.6 130 Nitrogen 500 2.6 1300 Phosphorous 100 2.6 260

Of the 12 inlets only NuwarawelaEla and RajapihillaEla (No 7 and 8) discharge relatively a large amount of N and P. Total annual load of ammonia-N and nitrate-N were 387 kg y -1 and 2096 kg y -1 while total phosphorous load was 758 kg y -1 (Table 3). This clearly demonstrates that Kandy Lake receives a large amount of N and P from two perennial inflows and a large number of waste water inlets. In addition, the Lake receives N and P compounds from several other sources as mentioned earlier. Further inputs of N and P are relatively larger than the outputs. In other words there is surplus of N and P in the Lake. A major portion N and P may consume by algae while different fractions may enter either food chain or deposit in sediment. Table 3: Nitrogen and phosphorous loading into Kandy Lake via twelve inflows.

Inflow No Ammonia-N (Kg y-1) Nitrate-N (kg y -1) Total-P (kg y -1) 1 8 44 33 2 32 143 52 3 7 75 41 4 6 14 47 5 8 314 89 6 17 65 60 7 122 726 158 8 161 432 175 9 10 199 48 10 4 60 17 11 3 14 30 12 9 10 8 Total 387 2096 758

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Apparently chl-a biomass in Kandy Lake showed an analogous oscillation with rainfall. Chl-a content decreases to lower level of eutrophy specially during two inter-monsoons (April-May and October -November) if the Lake catchment receives ahigh rainfall. A progressive increase in the chl -a content with an analogous decrease in water clarity was recorded from 1999 to 2004. Subsequently chl-a content increased to its maximum under extreme dry weather (February - March/July-August) with instances of being prolonged when a suff icient volume of freshwater is not brought into the Lake , due to delay or failure of monsoons rains, but just the nutrient loaded sewerage flows . Sub-surface hypoxia with an + accumulation of NH 4 -N in the deep waters were common during this period (Silva 2005). The seasonal oscillation of chl -a with rainfall is shown Figure 1. Like, temperate lakes, tropical standing water bodies also suffer climatic seasonal changes (especially related to monso on bound precipitation) that induce modifications in the physical and chemical characteristics of the water (Hooker & Hernandez, 1991; Costa & De Silva, 1995). Furthermore, the successions of phytoplankton are poorly understood in hypertrophic waters in th e tropics, in spite of the great importance of studies on water bodies submitted to anthropogenic influences.

Figure1: Chlorophyll-a and rainfall oscillation in Kandy Lakes Oscillation of a diatom and a green algae observed in Kandy Lake before it collap sed in 1999 may be a sign of meso -eutrophic successional episodeSamaradiwakara, 2003) . But progressive increase of M. aeruginosa following the outbreak exhibits a trophic shift toward hyper- eutrophication (Silva, 2005). Eutrophication, a global phenomenon usually results in the replacement of diverse phytoplankton assemblage to that of a few species with high densities(Talling&Lemoalle 1998). Although eutrophication is widespread in the humid tropics, documentation of outbreaks and aftermath are sparse. In the h umid tropics as elsewhere emergence of blooms and subsequent establishment of cyanobacteria have been attributed to phosphorous

Urban lake monitoring and management: Proceedings of an international symposium, 18 May 2012, Peradeniya, Sri Lanka.

loading. Nevertheless cyanoprokaryote dominance has been associated with several environmental factors such as: low turbulence (Reynolds, 1987, but see Ganf, 1974), low light (Zevenboom& Mur, 1980; Smith 1986), low euphotic to mixing depth ratio (Jensen et al., 1994), high temperature (Shapiro, 1990), low CO 2/high pH (King, 1970; Shapiro, 1990; Caraco& Miller, 1998), high total-P (McQueen & Lean, 1987; Trimbee&Prepas, 1987; Watson et al., 1997), low total-N (Smith, 1983), low total-N to total P ratio (Smith, 1983), low dissolved inorganic nitrogen (Blomqvist et al., 1994), phosphorus storage strategy (Pettersson et al., 1993), ability to minimize grazing (Haney, 1987) and buoyancy regulation (Reynolds, 1987). In non-harvesting water bodies with poor grazing efficiency by zooplankton, concurrentichthyo-eutrophication is very likely to accelerate the process due to accumulation of fish excreta. Apparently, the sudden emergence of scum forming algal blooms in the humid tropics is necessarily not a time series phenomenon. It may appear unexpectedly when apt hydraulic balance is coupled with favourable environmental variables (Silva 2005). With the onset of rainfall decrease in chl-a content, and increased water clarity may be attributed primarily to dilution and biomass loss via flow-through whereas shift in phytoplankton taxa is essentially a result of the changes in hydro-chemical environment. Diatoms grow lavishly when dissolved silica concentration is high while non-nitrogen fixing cyanobacteria become more abundant under high nitrogen concentration. In the present context, several factors are accountable for existing hypertrophic-eutrophic alternation in Kandy Lake of which hydrology is one of the most important driving force. It is observed the population densities of other cyanobacteria species in Kandy Lake insignificant compared to the dominant non-nitrogen fixing or non-heterocytic M. aeruginosa .Relative abundance of blue-greens is shown to have been positively related to temperature, but not to pH or total-P and to have been negatively associated with light, mixing, NO 3, but not with NH 4, t-N or t-N : t-P (Huszar et al.2000). Figure 2 is a schematic model which demonstrates algal biomass balance in Kandy Lake with respect to water budget, grazing pressure of tilapia and life strategy strategies of cyanomacteria. Biomass is gained only by rapid growth of cyanobacteria (doubling). It has reported that cyanobacteria population density can be doubled once in every twenty hours.

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Figure2:A schematic diagram of Cyanobacteria biomass mode

Cyanob acteria population in the Lake increases by doubling of cells (growth) if other con ditions (temperature, pH, light, nutrients etc.) are optimum. Simultaneously, biomass is lost from the system through the outfall, grazing by tilapia and natural death. In this non-harvesting Lake the tilapia population is regulated by cormorants and otter s, the grazing pressure is constant and the natural death of cyanobacteria is invariable. When the biomass is not passing though the outflow, it will increase within the Lake, perhaps may develop into a bloom. Under low water level, cyanobacteria may also get access to the phosphorous available in the deep layers (Silva, 2003). If water balance is not maintained effectively, existing seasonally hyper -eutrophic state maylead to an outbreak of cyanobateria bloom again. Therefore, continuous monitoring of wat erinput and output parameters together with retention time, basic physicochemical characteristics, nutrient concentrationand cyanobacteria biomass in terms of colony counts is imperative as a management too l.

4.0 CONCLUSION Kandy Lake is alwaysin ahypo-eutrophic state .With diminishing fresh water inflows, it rapidly reaches a critically unstable status. The year round rains over the catchments, helps to flush-out the lake in a more or less regular manner. I t’s lower storage capacity compared withthe volu me of freshwater inflows, helps to sustain this situation .With urbanization this flushing may happen more frequently. However, nutrient loaded waste water bounces it back to hypo - eutrophic condition in no time. Therefore, in the longer run the onsiteorlocal disposal of waste water would not help to save the health of this important Lake. The situationwould aggravate with the climate change .Predictions are not only flash rains , but also prolonged dr y periodsin between themand high air temperatures. In that li ght, the risk of algal bloom persists more than ever 94

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before. Therefore, it is wise to explore ways of reducing inflow gaps and nutrient loading. This cannot be done without active management of water in and around the Lake.

5.0 REFERENCES Blomqvist , P.Pettersson, A. and P. Hyenstrand, 1994. Ammoniumnitrogen:A key regulatory factor causing dominance of nonnitrogen-fixing Cyanobacteria in aquatic systems. Arch. Hydrobiol.(132): 141–164.

Caraco, N and R. Miller, 1998. Direct and indirect effects of CO 2on competition between a cyanobacteria and eukaryotic phytoplankton.Can. J. Fish.aquat. Sci. (55): 54–62. Costa, H. H. and P. R. Silva, 1995. Limnological research and trainingin Sri Lanka: state of the art and future needs.p. 1–39. In Gopal, B. & R.G.Wetzel (eds), Limnology in Developing Countries. SIL, Índia. Flett, R. J., Schindler, D. W. Hamilton, R. D. and N. E. RCampbell, 1980. Nitrogen fixation in Canadian PrecambrianShield lakes. Canadian Journal of Fisheries and AquaticSciences (37): 494–505. Ganf, G. G. 1974. Diurnal mixing and the vertical distributionof phytoplankton in a shallow equatorial lake (Lake George)Uganda. J. Ecol. (62): 611–629. Hooker, E.and S. Hernandez, 1991. Phytoplankton biomass in LakeXolotlan (Managua): its seasonal and horizontal distribution.Hydrobiol. Bull. 25(2): 125– 131. Huszar, V. L. M. Silva, L. H. S..Marinho, M. Domingos, P. and C. L. Sant’Anna 2000. Cyanoprokaryote assemblages in eight productive tropical Brazilian waters.Hydrobiologia 424:67–77. Jensen, J. P., Jeppesen, E.Olrik K. and PKristensen, 1994. Impactof nutrients and physical factors on the shift from cyanobacterialto chlorophyte dominance in shallow Danishlakes. Canadian Journal of Fisheries and Aquatic Sciences (51): 1692–1699. King, D. L. 1970. The role of carbon in eutrophication. J. Wat.Pollut. Cont. Fed. (42): 2035–2051. May, C. W.,.Horner, R. R Karr, J. R. Mar, B. W.and E. B. Welch,1997. Effects of urbanization on small streams in the PugetSound Lowland ecoregion.Watersh.protect.Techn. (2): 483–494. Reynolds, C. S., 1987. Cyanobacterial water-blooms.p.67–143. In: Callow, J.(ed.), Advances in Botanical Research, Vol. 13, Academic Press,London: Samaradiwakara S.R.M.S. 2003. Some Aspects of Limnology of Kandy Lake. M.Phil. Thesis, University of Kelaniya, Kelaniya, Sri Lanka,167 p. Schindler, D. W. 1977. Evolution of phosphorus limitation inlakes.Science (195): 260– 262. 95

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Shapiro, J.,1990 Currents beliefs regarding dominance by bluegreens:the case for the importance of CO2 and pH.Verh.int.Ver. Limnol.( 24): 38–54. Silva E.I.L. 2003.Emergence of a Microcystis bloom in an urban water body, Kandy Lake in Sri Lanka.Current Science , 85 (6): 723 - 725. Silva, E.I.L. 2005. Phytoplankton characteristics, Trophic Evolution and Nutrient Dynamics in an Urban Eutrophic Lake: Kandy Lake in Sri Lanka. p.227-270,In: Restoration and Management of Tropical Eutrophic Lakes (M. V. Reddy, ed.,) M/s Science Publishers, Inc., Enfield (NH), USA, Smith, V., 1983. Low nitrogen to phosphorus ratios favor dominanceby blue-green algae in lake phytoplankton. Science 221: 669–671. Talling J. F. and J. Lemoalle. 1998. Ecological Dynamics of Tropical Inland Waters, Cambridge University Press, Cambridge, 1998, 441 p. Zevenboom, W. & L. R. Mur, 1980. N2-fixing cyanobacteria: Whythey do not become dominant in Dutch, hypertrophic lakes. Dev.Hydrobiol. 2: 123–130.

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URBAN LAKES AS MULTIPLE USE SYSTEMS: NEED FOR COORDINATION AMONG STAKEHOLDERS AND INSTITUTIONAL ARRANGEMENTS

R Dalwani Director, NRCD, Ministry of Environment & Forests, Govt. of India

ABSTRACT In India a large number of man-made water-bodies that generally lie within municipal limits have turned over time into multiple use systems with many stakeholders. They may be used for drinking water supply to the surrounding urban population, for raising fisheries, for in-lake recreation (boating, swimming etc), aesthetics & lake shore recreation (parks), religious & cultural activities or for all of them at the same time. They may also attract important faunal species, particularly waterfowl and may be considered for their protection. These Urban lakes or wetlands are now in different states of degradation because of discharge of domestic wastes, siltation caused by storm runoff, dumping of solid wastes along the shoreline and various other polluting human activities, besides being affected on their water budgets. The conservation, restoration and management of these water-bodies have become a serious concern and a challenging task because of the multiple stakeholders and their conflicting interests. In India, these water-bodies are owned and controlled by different departments of the government at state, district or local level, such as Municipality/Local urban body/Public Works Department (PWD), Forest, Fisheries, Irrigation etc. The Ministry of Environment & Forests, Govt. of India has undertaken the task of restoration of these urban & semi urban water-bodies under the National lake Conservation Plan (NLCP) since 2001. Many lakes in different states have been selected by the respective State Governments for restoration and management with a major support from the Ministry through this centrally sponsored scheme. In this paper, two aspects of this programme are discussed based on our experience of implementation of the scheme. First, that the formulation of Management/Conservation Plan and its implementation requires active co-operation and support of all stakeholders besides the commitment and coordination between different agencies and stakeholders. Restored lakes directly benefit all stakeholders through improved aesthetics, better water quality, income from the goods and services provided by the lake and the overall quality of life. The second aspects is requirement of an appropriate Institutional arrangement which is extremely important for implementation of the combination of engineering & scientific interventions required for lake conservation, through different state agencies and their long term sustainability. Different kinds of institutional frameworks have been developed in different States in India and the results are mixed. In some states a separate ‘Lake Authority’ has been created for conservation & management whereas in others, an existing department of the local body has been designated as the nodal department for coordination and implementation. Some states have developed a common policy for all water-bodies in the state whereas others take decisions on lake to lake basis. Agencies are also required to monitor the progress of works & lake quality during implementation and thereafter without losing sight of various regulatory measures. Both these issues are discussed with examples of different urban lakes in India.

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1.0INTRODUCTION In India, there are relatively few natural lakes that lie mostly in the Himalayan region and in the floodplains of Indus, Ganga and Brahmaputra. However, in the semi-arid and arid regions of western and peninsular India, a large number of water bodies have been constructed in the past. These man-made lakes have been used mostly to store seasonally available water, usually for urban water supply and/or irrigation.Some of these are also used in fisheries require annual stocking with fingerlings with substantial inputs of fish feed. The biodiversity in these lakes is usually quite low. Most of the lakes in India, both natural and man-made, are in different states of degradation. Watershed degradation is the prime cause of degradation of these water-bodies besides eutrophication and siltation. During the recent decades, anthropogenic pressures on lakes such as deforestation, agriculture, urban settlements and industries have intensifiedtremendously resulting in the land use changes in their catchments. These anthropogenic activities have also accelerated the aging process as large amounts of sediments, nutrients and toxic substances enter the lakes with the runoffscausing eutrophication, toxic pollution or habitat loss. The catchment-based activities are many a times accompanied by encroachments on lake-shores through reclamation of shallow lake margins, sewage disposal, water abstraction, and diversification of in-lake recreational activities. All these activities directly impact the pace of degradation. The conservation, restoration and management of these water-bodies, particularly in urban areas,has become a serious concern and a challenging task because of the multiple stakeholders and their conflicting interests. In India, these water-bodies are owned and controlled by different departments of the government at state, district or local level, such as Municipality/Local urban body/Public Works Department (PWD), Forest, Fisheries, Irrigation etc.The Ministry of Environment & Forests, Govt. of India has undertaken the task of restoration of these urban & semi urban water-bodies under the National lake Conservation Plan (NLCP) since 2001. The programme has gradually unfolded the complex problems in undertaking various restoration activities and the institutional arrangement to support the programme. In this paper, some major features of this programme are discussed along with various institutional arrangements made in different states.

2.0 NATIONAL LAKE CONSERVATION PLAN The Ministry of Environment and Forests, Government of India, has been implementing two flagship programmes on conservation of wetlands & lakes in the country. A National Wetland Conservation Programme(NWCP) was initiated by the Ministry during 1987 where in 115 wetlands have been identified for conservation. However, considering the difference in the nature of 98

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activitiesrequired for the conservation of lakes, especially in urban & semi- urban areas with greater need of pollution abatement, a separate scheme named National Lake Conservation Plan (NLCP) was initiated in June, 2001. The objective of NLCP is to restore and conserve the urban and semi-urban lakes in the country degraded mainly due to waste water discharge into the lake and other unique freshwater ecosystems, through an integrated ecosystem approach.

3.0PRIORITIZATION OF LAKES While the causes of degradation of lakes are many, in view of the limited resources available, it has not been possible to take up all degraded lakes for conservation under NLCP at the same time. It was therefore, felt necessary to prioritize lakes along with the catchments, where conservation programmes need to be taken up first. In order to identify polluted and degraded lakes across the country, a study was carried out by the Ministry on the request of the Planning Commission, where 62 lakes were identified across the country for conservation. This list was sent to all State Governments for their consideration and finalization, keeping in view the state priority and the justification for their inclusion in the priority list. The state priority and justification for such a selection has been a pre-requisite for consideration of the proposal under NLCP. In view of the prevailing dynamic situation, states if required, may revise the priority list at an interval of 5 years for covering different geographic regions of the state.

4.0 SELECTION CRITERIA Selection of lakes for conservation is based on the criteria outlined in the NLCP guidelines published as a part of the scheme: 4.1Hydrological Criteria The lake water body is perennial i.e. it holds a certain volume of water at all times, even in the lean season of the year.Physical parameters of the lake are:Lake size > 10 ha (Exception: lakeslarger than 3 ha having socio-culturalor religious importance), and maximumdepth > 3m

4.2Scientific Criteria • The lake is justifiably prioritized by the concerned State Government or if the water body is highly degraded and cannot be put to its traditional use primarily because of (a) discharge ofdomestic and industrial waste water into the lake or (b) dumping of municipal solid wastes or other non point sources of pollution and flow of heavy silt loads for the catchment. • The lake water body is degraded and not meeting the desired water quality criteria. In the absence of specific water quality criteria developed in respect of lakes, for the present Designated Best Use criteria for surface waters for bathing 99

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quality as given by Central Pollution Control Board (CPCB) shall be the target for maintaining lake water quality (Box-4)Inappropriate land use leading to heavy soil erosion and sediment transport into the lakeresult in nutrient enrichment of lake (nitrate and phosphate) signifying eutrophication. 4.3Administrative Criteria • The lake if getting degraded/eutrophied, is an important source of drinking water supply, domestic use, recreational use, provide other goods and services, may be proposed under NLCP, when, a) there is a high degree of demand from a public forum/local stakeholders for its conservation and, b) if the forum/ stakeholders give their commitment to bear 10% out of State share in the project cost. • Lake categorized as a ‘unique fresh water ecosystem . 4.4Other Conditions The proposals for lake conservation considered for support under the Programme are required to additionally take into account the following:

(i) The stakeholders involved and the impact of lakedegradation on each of them as well as their involvement in operation and maintenance. (ii) Adequate bathymetric data of the lake, especially where de-siltation is proposed as a major component. (iii) ‘Lake Front Development’ activities should be restricted. (iv) Naturalisation of shoreline with appropriate vegetation should be the preferred option in place of structural works. (v) The water quality after implementation of theproject should meet the criteria for B class of the Designated Best Use classification of Central Pollution Control Board (CPCB) notified by the Ministry. (vi) Recycling and reuse of sewage should be considered to minimize adverse impacts on the lake.

5.0ACTIVITIES COVERED UNDER NLCP The activities covered under NLCP include the following: Water quality criteria for B class outdoor • Pollution from point (bathing) of Designated Best use Classification sources is prevented by as notified by the Ministry Fecal Coliforms Desirable: 500 MPN/100ml intercepting, diverting and treating Maximum: 2500 MPN/100ml the pollution loads entering the Fecal Streptococci Desirable: 100 MPN/100ml lake. The interception and Maximum:500 MPN/100ml diversion works may include pH between 6.5 and 8.5 Dissolved Oxygen 5 mg/l or more sewerage & sewage treatment for Biochemical Oxygen Demand(3 days at 27oC)3 the entire lake catchment area. mg/l or less • In situ measures of lake cleaning such as de-silting, de- 100

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weeding, bioremediation, aeration, bio-manipulation, nutrient reduction, withdrawal of anoxic hypolimnion, constructed wetland approach or any other successfully tested eco-technologies etc depending upon the site conditions. • Catchment area treatment which may include afforestation, storm water drainage, silt traps etc. • Strengthening of bund, lake fencing, shoreline development etc. • Lake front eco-development including public interface. • Prevention of pollution from non-point sources by providing low cost sanitation. • Public awareness and public participation. • Capacity building, training and research in the area of Lake Conservation. • Any other activity depending upon location specific requirements

6.0 STATUS OF NLCP Recognizing the ecological services rendered by the lakes and wetlands, the Ministry of Environment & Forests, Govt. of India, launched a separate conservation programme for Lakes besides the ongoing scheme of NWCP. The National Lake Conservation Plan (NLCP) is presently under implementationas a Centrally Sponsored Scheme since June, 2001, for conservation and management of polluted and degraded lakes in urban and semi-urban areas of the country, on a 70:30 cost sharing basis between the Central Government and the respective State Governments. An initial allocation of Rs.25 crore was made for NLCP during the IX Plan period. NLCP received a significant response from the State Governments and proposals for the restoration of a number of lakes were received for consideration. So far, the Ministry has sanctioned 44 projects for conservation of 61 lakes in 14 States at a total cost of Rs.1028.19 crore under this scheme. The financial allocation under the scheme has been substantially increased over the years from Rs.25 crore in IX Plan to Rs.220 cr. in X Plan and Rs.440 cr. in XI Plan. Conservation under NLCP is being carried out with an institutional support based on the prioritization of lakesdone by the respective State Governments which intern is based on scientific criteria and keeping local demands in view. Prioritization also helps in appropriate budget allocation for the lakes at the ‘Plan Budget’ stage. Since the NLCP scheme is implemented on the basis of a cost sharing between the Central Government and the States, the commitment on the part of participating State is also ensured for consideration of the project. 6.1 Monitoring Mechanism For improving implementation and enhancing coordination between the Centre, the States and the Urban Local Bodies, the Ministry of Environment and Forests has asked all States to constitute City Level Monitoring Committees (CLMCs) for lake conservation projects. The CLMCs are chaired by the District 101

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Collector and include the administrative head of the ULB, representative of implementing agency, an environmental NGO and a prominent social worker. Besides ensuring timely implementation, monitoring flow of funds and better coordination between concerned agencies, the CLMCs are also expected to secure public cooperation and facilitate community mobilization for the conservation of lakesin the region. 6.2Education and Capacity Building The Govt. of India has recognised the need for adequate trained manpower in various scientific & technical, social, economic, administrative aspects of conservation of lakes to prepare and implement programmes/projects/schemes of environmental conservation, operate and maintain the assets created for conservation of water bodies, and monitor the environmental status of projects undertaken. The Ministry has therefore sponsored a multidisciplinary course “Conservation of Rivers & Lakes” with Indian Institute of Technology, Roorkee, for capacity building of in-service officers of the state, local and Central Government. Besides the 2 years M-Tech course, the programme also offers short-term refresher course of 5 to 10 day durations on various aspects of Lake & River conservation including that on preparation of Detailed Project Reports (DPRs) for such projects 6.3Policy Initiatives The degradation of lake systems together with their watershed is also impacted by the policies governing the activities in the lake catchment such as the policies related to agriculture, change in land use, water abstraction and various in-lake activities. Identification of the role of stakeholders and public participation are also important facets of lake restoration and need to be addressed adequately. Another key issue in lake management is the economic efficacy. The beneficiaries of lake restoration and those responsible for it often remain different entities. This results in a financial mismatch affecting the lake restoration and its long-term sustainability.

7.0 INSTITUTIONAL FRAMEWORK The conservation and management of lakes is a multidisciplinary task of a high magnitude and requires cooperation, coordination and commitment of different agencies. A healthy functioning lake ecosystem is critical not only to its biotic community but also directly affects its stakeholders through improved aesthetics, better water quality, income from the goods and services provided by the lake and the overall quality of life of the people living in the lake catchment. The lake rejuvenation projects not only require appropriate institutional arrangements for the timely implementation of various civil, biological, socio- economic components and their long-term sustainability, but are also important for developing a holistic approach, proper coordination, providing a resource base, financial sustenance, accountability and a strong regulatory mechanism. 102

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There is also a need for developing the lake restoration proposals in concordance with other ongoing governmental and non-governmental programmes and investments of any kind in the lake catchment. Lakes are multiple use systems and have therefore many stakeholders. Quite often, the same water body is managed by several agencies/departments with conflicting interests. The departments of Public Health Engineering, Water Supply, Fisheries, Irrigation, Urban Development, Tourism and Forests and Environment are among the common ones responsible for maintaining the water bodies in different States. The catchments are also used variously and controlled by different stakeholders depending upon their nature. The multiplicity of agencies involved in the use and management of the lakes is an important cause of their degradation. The lakes have turned from common property resources into open access resources. Even the municipal bodies which use the water for domestic supplies allow the wastewater discharge and solid waste disposal into the water body by turning a blind eye to the problem. Another important component of lake management is the proper identification of stakeholders and their respective roles including participation in the conservation programmes, the beneficiaries of lake management and restoration, and those responsible for it often remain different entities that may never communicate and meet with each other. The economic efficiency of the restoration and post-project maintenance is a key factor in the sustainability of the programme. Thus strong institutional mechanisms are required for coordination between different user agencies and concerned organisations and for stakeholders’ participation in conservation and management. It is most desirable to have a single apex body to manage such natural resources within a State. However, it is not practical to provide for an uniform system of institutional arrangements throughout the country. Various State Governments which have implemented programmes of rehabilitation of lakes under the NLCP or on their own have opted for one of the two arrangements: (a) constituting a Lake Development Authority to manage a specific lake in the State. or (b) bringing all water bodies within the State under the jurisdiction of one Lake Development Authority. There is as yet no specific institutional mechanism at the national level but a need is being felt to develop a central regulatory and monitoring mechanism for guidance to the States and for the sustainability of the conservation programme. Such a national institution or Authority is required together with the required expertise from different fields of ecology, conservation, technology, management techniques, social sciences, and economics for developing a scientifically sound, socially acceptable, holistic approach to 103

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sustainable management and conservation of the lakes and wetlands. Such a national body is also required to provide guidance on developing restoration proposals in conjunction with other governmental (central and state) programmes that are directly related to the water bodies or have a bearing on their conservation. In Karnataka, a Lake Development Authority was created in July, 2002, with its office in Bangalore, as a registered Society under the Karnataka Societies Registration Act, 1959. This Lake Development Authority is an autonomous, regulatory, planning and policy making body for the Protection, Conservation, Reclamation, Restoration, Regeneration and Integrated Development of Lakes, whether natural or manmade in the state of Karnataka. Its jurisdictionextends to the entire state. The Authority is headed by the Chief Secretary, Government of Karnataka, and the Chief Executive Officer of the Authority isits Member Secretary. In Madhya Pradesh, the Government has constituted a Lake Conservation Authority (LCA) under the overall guidance of the Chief Secretary of the State. After successful implementation of the multidisciplinary Bhoj Wetland project for integrated conservation and management of the Upper and Lower Lakes of Bhopal (a Ramsar site), with the assistance of the Japan Bank for International Cooperation (JBIC, now Japan International Cooperation Authority, JICA), the State government constituted the LCA and registered it as a Society in May 2004, to execute post-project conservation and management works of Bhopal Lakes as well as other water resources of the entire State. In Manipur, the Loktak Lake Development Authority was set up specifically for coordinating the conservation activities in lake Loktak, also a Ramsar site. Similarly, in Orissa, the Government constituted the Chilka Development Authority (CDA) headed by the Chief Secretary, and managed by a CEO. The CDA was responsible for the restoration of the Lake Chilika, one of India’s oldest Ramsar sites. After evaluating several options, the CDA decided on dredging out a direct connection between the lake and the Bay of Bengal to improve its hydrological and salinity regimes. The successful restoration saw a several-fold increase in fish catch and earned it the Ramsar Award for India in 2003. In Uttarakhand, the conservation programme for Lake Nainital and other lakes in the regions is coordinated by the Commissioner of Nainital without the status of an Authority. Similarly, in Maharashtra, the conservation of lakes is supervised by different bodies at the individual lake level with monitoring at district & State Govt. levels. In Rajasthan, the restoration of lakes was started with the Mansagar Lake in Jaipur. The work was initially supervised by the Jaipur Development Authority which faced difficulties in coordinating the activities related to the renovation of the Sewage Treatment Plant and in-lake treatment using bio-remediation. Later, the State government constituted an apex body chaired by the Chief Secretary that brought several concerned stakeholders together. Now the State 104

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has taken up programmes for rehabilitation of several other lakes of touristic importance namely Fatehsagar, Pichhola, Pushkar, Anasagar and Nakki. While the activities related to these lakes are implemented by the Local Urban Bodies in respective cities, the government has constituted a State level apex body, a Standing Committee for Policy Formulation and Regulation of Lake/River Development Programmes, with the Chief Secretary as its Chairman. Principal Secretaries of all concerned departments and a few academic experts are its Members. In the State of Jammu and Kashmir, the Government has set up a Lake and Waterways Development Authority (LWDA) which is chaired by the Chief Secretary, and a Vice Chairman looks after its functioning. The LWDA is presently involved in the implementation of the conservation programme in Dal-Nigeen lake basin under the NLCP. The LWDA presents one of successful examples of institutional framework though not without certain issues & gaps. While the required manpower from different departments have been drawn up & brought under the umbrella of LWDA making the project implementation quite effective, it lacks the financial & statutory back-up for regular maintenance of infrastructure & initiating action against the polluters. Frequent changes in the apex level in these implementing agencies additionally affect the pace of project and subsequent operation & maintenance thereby the project sustainability.

8.0CONCLUSION & WAY FORWARD Over the years, the Ministry as well as the State Govts.have been learning from the increasing need for conserving the lakes in the country through improved Project implementation & a sound Institutional mechanism. Based on the experience gained over the last decade, the Govt. of India while seeking a better participation of States in NLCP during the XII Plan, has also desired for constitution of State Level Lake Development Authorities for comprehensive implementation of Conservation Plans, resource generation for Operation & Maintenance and statutory support for affecting regulatory measures.

9.0 REFERENCES Ministry of Environment & Forests (NRCD). May, 2008. Guidelines for National Lake Conservation Plan. Ministry of Environment & Forests (NRCD). July, 2010. Conservation and Management of lakes – An Indian Perspective.

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RESTORATION OF THE RIPARIAN ZONE OF LAKE RICHMOND THROUGH LANDCARE

Kamal Melvani 1 and S. Pathmarajah 2

1Neo Synthesis Research Centre (NSRC) 2Faculty of Agriculture, University of Peradeniya

ABSTRACT Lake Richmond is a manmade Lake located between the Thotulagalla and Pitarathmale Tea Estates in the Lipton’s Valley in Haputale. This peri-urbanLake was created by the British in the 1800s to generate hydropower for a downstream coffee factory and currently provides the Estate Labour community with water for domestic and agricultural use. No riparian vegetation exists aside from the aquatic plant, Cyperus rotundus. These large stands of aquatic vegetation though invasive, provide a buffer for waste entering the Lake including agrochemicals from the surrounding tea plantations and vegetable gardens, faecal matter and grey water from the line rooms of the estate community and the Thotulagalla Tamil Vidyalayam (school). The Neo Synthesis Research Centre (NSRC) initiated a restoration of the riparian zone of Lake Richmond in 2009 by establishing a vegetation buffer to trap sediments and bioremediate waste whilst providing habitat for biodiversity. It was also the first time that native vegetation was used to mitigate the potential of landslides in Sri Lanka. An inventory was carried out on flora and fauna found in the nearby remnant natural forest and most of the flora species were used in restoration. The work was carried out in collaboration with students of the Thotulagalla Tamil Vidyalayam, a secondary school located adjacent to the Lake, farmers living in the downstream area, Management of the two Estates, Pradeshiya Sabha 5 (Diyatalawa), Forest Department, (Haputale), Landcare Lanka and NSRC. The Landcare philosophy guided this participatory restoration process and proved to be highly effective. In 2010, the area around the Lake was declared the Lake Richmond Nature Park. Monitoring activities are currently underway.

1.0 INTRODUCTION The Lipton’s Valley in Haputale is composed of a series of smaller valleys and located in the Kalkanna Oya sub basin of the Walawe river watershedin Sri Lanka. It is 133.13 km 2 in extent. Three hundred and ninety-nine (399) streams of 1st, 2nd and 3rd orders flow down the mountains to form a 4th order stream called Lemastote Oya. This stream joins the Weli Oya downstream to form the Kalkanna Oya which, in turn, feeds the Walawe river system. Land use in the Lipton’s Valley is dominated by tea planted by three large Tea Estates, namely Thotulagalla, Pitarathmalie and Dambetenne.

5 A local government body 107

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Lake Richmond is located at the base of the Valley that spans Thotulagalla and Pitarathmalie tea Estates. Constructed by British Planters in the early 1800’s, the lake was created by excavating a large wetland area. One possible reconstruction of land use prior to excavation suggests that the streams that flowed down these mountains entered the wetland and then continued on downstream. The area would have been covered with montane cloud-forest as evidenced by a small remnant patch still remaining nearby. The Lake water was used to drive a downstream turbine to generate electricity for a coffee processing factory. When a virus affected the coffee industry, the land was converted to growing Camellia sinensis or tea. Presently, the Lake water is used by upstream and downstream communities for domestic and irrigation purposes. They have pipes that draw water from the Lake and, during the drought when water levels recede, conflicts arise among water users. The micro watershed of Lake Richmond is 0.025 km 2 in extent (Kumarihamy, 2012). Three 1 st order streams feed Lake Richmond. The microwatershed was bereft of any vegetation other than tea Cyperus rotundus and a few ‘high shade’ trees, Grevillea robusta, until NSRC initiated the project in 2009. With no under storey vegetation beneath the tea on the Pitarathmalie Estate side of the Lake and with the large-scale application of herbicides like Roundup  (Glyphosate) in tea fields, all the vegetation is killed. Without any roots to hold soil in this unstable terrain (Wijewickrema, 2009) in the rainy season, soil erodes and washes into the streams. Hence, there is a strong possibility that residues of other agrochemicals are carried along with the sediment into the streams. Some of the agrochemicals that are applied include nitrogen-based fertilizers like Urea, Dolomite and other specialty mixtures. Contact fungicides 6 that are Copper based (e.g., Copper oxide, oxychloride or Hexachloride) and systemic fungicides like ‘Shakti’ (Hexaconazole) are frequently used. However now that ‘buffer zones’ have been established along many of the feeder streams on Pitarathmalie Estate, the potential for the entry of eroded soil into the streams is reduced. The situation on the Thotulagalla Estate side of the lake on is different. The Estate is a certified organic tea producer and no agrochemicals are used. The Estate labour community who occupy about 7 ha of land in the upper reaches, however, cultivate vegetables using diverse agrochemicals including fertilizers, pesticides and fungicides. Since the streams flowing through the vegetable gardens are devoid of tree cover and given that many gardens are located directly above the Lake, these chemicals may enter into streams that feed the Lake.

6A c ontact fungicide kills a pathogen/fungus upon contact and is not absorbed by the plant. Systenic fungicides have the ability to be absorbed by the plant tissues and could leave behind residues with better controllability (Tea Research InstituteCircular PU 2, Serial No: 04/08, November, 2008). 108

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Many people in the Thotulagalla Estate Community live in barrack type ‘Line rooms’. The Estate has a population of 730 persons and 88 toilets, presenting a toilet to human ratio of 1:8. The Management intends to construct more toilets in the future. Grey water from some of the line room areas drains directly into the gullies (c and b1) that feed the Lake while a greater volume discharges into a larger gully located centrally that joins streams linking with the Lemastote Oya downstream. The Thotulagalla Tamil Maha Vidyalayam that is also located by the Lake has 6 toilets for 180 children, a toilet to human ratio of 1:30. Most of the school drainage for waste water enters the gully ‘c-school’ that emerges from the line areas upstream and discharges into the Lake. A lesser volume of grey water discharges into a stream flowing adjacent to the school on the opposite side that links downstream with the Lemastote Oya. Compounding these issues is the looming threat of landslides since this area has been declared a high hazard zone (Wijewickrema, 2009). The landslide threat is enhanced since any movement of soil/mud into the lake will be accompanied by large volumes of Lake water posing a greater danger thereby. Only one patch of remnant montane cloud forest can be found in the upper reaches of the Pitarathmalie Valley that is approximately 12 ha in extent and represents the only natural forest in the entire Lipton’s Valley. Given the degraded nature of the micro watershed of the Lake and its consequent impact on water quality, an experiment in lake restoration was undertaken by NSRC in 2010 with financial support from Art Gold Sri Lanka. The objectives were: 1. To engage in collaborative restoration where all stakeholders in the community come together to implement and manage the effort - students of the Thotulagalla Tamil Vidyalayam, Estate Communities, Tea Estate management, Local government administration and the facilitators NSRC and Landcare Lanka. 2. To restore the riparian zone along gullies a, a 1, b, b 1,c and c-school that feed Lake Richmond and gullies e and f that flow out of Lake Richmond by planting buffer vegetation that prevent waste from entering the streams. Gully d would not be restored since it was large and could not be completed in the given time frame. Please see Figure 1 .

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Figure 1: Scope of activities planned. To restore tree dominant vegetation around the Lake that will serve to biologically mitigate the impact of a landslide and recreate habitat for aquatic and semi aquatic fauna. 3. To restore vegetation along the ridge of the mountains towering over the Lake to impede erosion. 4. To establish the first ever ‘Nature Park’ around Lake Richmond under the control of the Pradeshiya Sabha, Diyatalawa who will develop the area for ecotourism.

2.0 MATERIALS AND METHODS Figure 1describes the scope of the restoration planned and the activities that followed. Participatory planning : At the very start, discussions were held with implementing partners to draw up a collaborative programme. Preliminary meetings were held with Greenfields Bio Plantations, the holding agents for Thotulagalla Estate since much of the land area above the Lake came under their purview. Similarly meetings were held with the Management of Pitarathmalie Estate since most of the land immediately around the Lake was under their jurisdiction. Discussions were also held with the Pradeshiya Sabha, Diyatalawa, to enlist their support since the area around the Lake had been nominated for ecotourism. NSRC met with the Principal of Thotulagalla Tamil Maha Vidyalayam in order to organise a school programme in environmental education where permission was sought from the Zonal Department of Education, Bandarawela. Officers from the Department regularly participated in the meetings held with students to develop the area around the Lake as a Nature 110

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Park. Three student environmental cadet groups were initiated. NSRC met with the Regional Forest Office, Haputale to request for their support and clearance to restore the fragmented natural forest above Thotulagalla Estate. The participation of the Estate communities was sought through a series of person- to-person meetings with staff visiting the homes of 116 families where 53 families who showed interest were invited to a meeting with all other stakeholders. Since the Project had adopted the LANDCARE 7 philosophy the aim was to: a) Form a Landcare Committee of representatives of all stakeholders. b) Form Landcare Groups comprising beneficiaries who were interested in participating in the work. This preliminary meeting was held on 30 th March 2010, at the Greenfield Fair Trade Cultural Hall and was attended by all of the stakeholder groups and a majority of members of the Estate labour community. All the participants representing different stakeholders were encouraged to express their views and describe their possible interactions with the Project. The meeting culminated in the formation of a Landcare Committee with representatives from each stakeholder group. Subsequently a meeting was held with farmers who lived downstream from Lake Richmond. Fifty-three beneficiaries attended and after an animated discussion that focused on the restoration of the Lake watershed, an action plan was drawn up. Three farmer Landcare Groups were formed and a series of meetings followed to discuss the implementation of the plan. Of significance was that the farmers requested training in organic agriculture since their main objective was to reduce or completely stop using agrochemicals in cultivation. This was how they proposed to care for the land. Meetings were also held separately with livestock farmers who lived in the downstream of Pitarathmale and Thotulagalla Estates since they grazed their goats on the grass in the Lake area or cut grass ( Brachiaria brizantha ) on the mountain slopes to stall-feed their cows. Farmers agreed to cultivate CO3 grass instead. Following up, three training sessions were held for milk producers in a bid to increase milk productivity. The Provincial Veterinary office conducted these trainings. Ecological restoration in the Lake micro-watershed Mapping the watershed As a preliminary step, GIS Mapping of the micro watershed was initiated to facilitate the landscape design for planting. Mapping the resources Subsequently, an inventory of flora and fauna in the only forest patch in the micro watershed was completed. This enabled the selection of species that

7Landcare seeks to address rural land degradation in a cooperative and coordinated manner that involves everyone from community Landcare groups to the corporate sector and government agencies (Lockie, 1999) 111

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would be used in the landscape design and paved the way for plant propagation since forest species are difficult to purchase. Setting up the nursery to propagate plants A nursery was established in the land belonging to the Thotulagalla Tamil Vidyalayam. The students of the Environmental Cadet groups operated the nursery and, by the end of November 2010, more than 24,000 plants of native species had been propagated. These plants will be used for planting. School model in organic agriculture The land above the nursery was converted to an organic vegetable garden where students engaged in vegetable cultivation. NSRC staff taught the students methods of making compost, liquid fertilizer and biological pesticides. The vegetables harvested were sold and monies deposited in a bank account with funds used for students’ welfare. Lake Richmond Nature Park With the onset of the monsoon rains, planting began. Since the Lake area was ‘visible’ to the public, a festive inauguration was held and attended by local politicians, government officials, members of the Estate community, Thotulagalla and Pitarathmalie Estate management and school children. The ceremonious tree planting was inaugurated by holding a religious event ( pooja) in keeping with the cultural norms of the Estate community and signalled the start of the restoration activity. Planting in the micro watershed around the Lake A total of 4,724 trees and plants of more than 39 native and indigenous species were planted in the micro watershed of Lake Richmond. 1,193 were planted around the Lake while 3,081 were planted in Gully a 1-Upper Lake area, Gully b-Upper Lake area, Gully b 1-Lower Lake area Gully-c, Gully ‘c-School’, Gully-e and Gully-f in the downstream. Figure 2 depicts the planting around the lake with each dot representing a plant. Table 1 describes the species used therein. In preparation, the land had been cleared of large weeds. Large stands of grass-Iluk ( Imperatacylindrica) and Maana (Cymbopogon nardus) were removed with their roots to prevent their return. Thereafter, holes were dug in three/four parallel rows around the Lake and alongside the gullies. Before planting was initiated in an area, staff moved the plants from the nursery to the designated planting spot. This was perhaps the most difficult exercise since moving 2000-3000 potted plants upstream weighted with wet soil in the cold mist and slippery soil surface in a leeches infested area was really tedious. Gully planting was then undertaken in a tier like manner; the smallest plants or shrubs like Strobilanthes sp ., Clerodendron chinense, Costus specious and Impatiens walkeri were planted first in a dense manner. These were followed by 112

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larger shrubs like Alpinia calcarata, Alpinia zerumbet, Hedychium coronarium and large ferns like Cyathea sp. In places that erosion was experienced, Bamboo species – Bambusa vulgaris, Dendrocalamus giganteus and Ochlandra stridula were planted. Thereafter rows of small and large trees were planted, depending on site quality and space available. Species of small trees used included pioneers like Acronychia pedunculata, Homolanthus populifolius, Macaranga indica, Neolitsea cassia and Trema orientale. Large trees planted included Euphoria longana, Garcinia quaesita, Litsea ovalifolia, Meliosma pinnata, Michelia champaca, Myristica dactyloides, Neolitsea fuscata, Calophyllum tomentosum, Syzigium assimile, Syzigium umbrosum and several unidentified forest species.

Figure 2: Planting around Lake Richmond 113

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Table 1: Plants established in the micro watershedof Lake Richmond

Scientific Name Common Name Lake Gully C Gully D Gully E Gully Gully a1 a1 Gully Lake area Lake Down area Down Around the the Around Total plants Total Gully B - Lake Lake - B Gully Gully b - Upper Upper - b Gully Gully C - School - C Gully Upper Lake area Lake Upper Aconychia pedunculata Ankenda 10 4 67 76 30 25 15 97 324 Agave rigida var. sisalana Hana 8 8 Alpinia calcarata Heen Aratta 8 23 41 33 6 7 28 72 218 Alpinia zerumbet Maha Aratta 103 10 75 16 2 40 62 308 Dendrocalamus giganteus Green Bamboo 1 5 6 Bambusa vulgaris Yellow Bamboo 1 1 1 3 Calophyllum tomentosum Thel Keena 13 37 33 11 12 20 84 210 Cassia spectabilis Cassia 1 1 Chryssophyllum cainito Star apple 2 2 Clerodendrum chinense Pinna 2 2 7 2 13 Costus specious Thebu 1 12 2 4 19 Cyathea sp. Tree fern 1 1 Erythrina lithosperma Erabadu 3 3 Euphoria longana Mora 0 Ficus hispida Kotadimbula 7 9 6 22 Forest species Forest species 34 87 1 83 31 29 58 121 444 Garcinia quaesita Goraka 1 1 4 3 1 10 Hedychium coronarium Wild Ginger 84 30 67 62 97 170 510 Homolanthus populifolius Rathu Kenda 44 85 10 70 13 11 31 83 347 Impatiens sp. Wild Impatiens 2 2 Litsea ovalifolia Beeriya 12 15 21 11 6 19 42 126 Lobelia nicotianifolia Wild Tobacco 1 1 16 18 Macaranga indica Bukenda 2 3 2 8 20 38 1 60 134 Meliosma pinnata Nika dawula 3 3 Michelia champaca Sapu 14 5 15 4 4 4 44 90 Myristica dactyloides Malaboda 13 13 2 27 13 26 4 63 161 Neolistea fuscata Kududawla 5 40 1 25 8 7 8 78 172 Neolitsea cassia Dawul Kurundu 15 61 1 30 17 12 27 53 216 Ochlandra stridula Forest bamboo 10 4 1 15 Osbeckia lanata Heen Bowitiya 4 1 1 2 3 29 40 Pavatta indica Pavatta 6 6 Pongamia pinnata Karanda 1 3 1 11 11 26 53 Strobilanthes sp. Nelu 59 90 89 150 63 105 60 51 667 Syzygium assimile Damba 21 3 13 14 5 4 33 93 Syzygium sp. Alubo 1 1 1 3 Syzygium umbrosum Heen Damba 1 3 1 7 1 6 19 Trema orientale Gadumba 1 1 Wendlandia bicuspidata Sawan Idala 1 1 2 2 6 Total Plants Established 365 581 290 690 344 381 430 1193 4274

Areas that were dominated by rocks were planted with the shrubs like Lobelia nicotianifolia, Osbeckia lanata, Wedlandia bicuspidata and small trees like Ficus hispida . Species like Pongamia pinnata, Chrysophyllum cainito, Cassia spectabilis, Erythrina lithosperma and Pavetta indica were planted in the interface between land occupied by the Estate community and the riparian zone. Rows of the thorny plant Agave rigida, var. sisalana were planted as fire belts in areas prone to the fire hazard.

3.0 RESULTS AND DISCUSSIONS A major problem remains in areas where herdsmen continue to graze goats on the grasses around the Lake. Several meetings were held with the herders but the problem remains. Aside from this, the plants are one year older and most species show impressive growth rates because roots have reached the shallow ground water depth of the Lake micro watershed. However the plants 114

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established above the Lake experienced a deathblow last year (2011) when during the period of the ‘grease devil’ saga, public unrest reigned and people set fire to the grassland above the Lake killing many of the plants. The Landcare Groups continue to function but there is the need to bolster their momentum since the movement is new and groups require continuous mobilization. On the other hand, the rigorous propaganda of agrochemical companies who offer ‘easy’ pest control and increased yields threatens the transition to organic agriculture and thereby the focus of the group. Despite the lower costs involved, some farmers are loath to spend time in making compost, liquid fertilizer and biological pesticides. The same is true for the organic farmers who practice upstream, on Thotulagalla Estate. The force exerted by the “going with the Joneses” thought process or farm like the other farmers is a challenge that can be resisted only by a few. Work in the Thotulagalla School continues with more time being allocated for the students to engage in organic agriculture while work in the plant nursery proceeds unabated. The majority of the plants generated last year were used in the planting of the gullies and mountain ridge on Thotulagalla Estate as well as in the microwatershed of the Lake. The Pradeshiya Sabha, Diyatalawahave cleared errant construction in the immediate area around the Lake. The Grama Sevaka Niladhari 8 is monitoring the management of garbage being thrown in the immediate Lake area. The Thotulagalla Estate has taken several steps to establish a bio fertilizer- manufacturing unit where pile compost, vermicompost, vermi-wash and liquid fertilizer are produced on a large scale. NSRC trained local youth from the Estate community who now operate the unit. The application of these biological inputs is ongoing though and the results are being monitored. Needless to state that positive changes in yields and the ability for the crop to withstand increasing rainfall variability with climate change will certainly increase the replicability of these regenerative technologies to the rest of the tea sector. Pitarathmalie Estate, according to the dictates of Rainforest Certification, has established buffer zones alongside each stream. These buffer zones are 3 - 10 m in extent and delineated by rows of Gliricidia sepium. It is hoped that agrochemicals are not applied in these zones. The restoration carried out was collaborative since it brought together on one platform several different types of stakeholders with a common focus of interest. While the results in the short term are positive, an endeavour of this nature is best assessed in the longer term. The ultimate challenge is for a restored ecosystem to endure and be able to sustain itself. In this case the environment is fraught with difficulties ranging from continuing poverty in the Estate labour community, worker unrest, decreasing productivity, increasing

8 Village level government officer 115

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costs (depreciation of the Sri Lanka rupee), fluctuations in the global tea market, climate induced impacts like increasing rainfall variability etc. Some of these challenges can be understood and dealt with like the invasion of Cyperus rotundus that could be managed by mechanical means. The danger posed by goats eating the plants could be addressed through continued discussions with the herdsmen, Estate management and representatives of the local authority. Similarly herdsmen who destroy plants will need to be approached, once again in conciliatory vein to reassure them that there is no threat from the plants established shading out the Brachiaria grass that they harvest. Information about increasing milk production through the use of other fodder grass varieties like Napier/CO3 as well as tree fodder like Gliricidia must continuously be shared with them. Further, the Pradeshiya Sabha, Diyatalawa and Provincial Ministry of Tourism must step up to advertise the Lake Richmond Nature Park as an attractive destination if the sustainability of this endeavour is to be realized. However there are some challenges that are more difficult to counter: the ability to engage in this restoration endeavour was only possible with the financial support received by Art Gold Sri Lanka and many people who gave their time voluntarily to the programme. Given that an undertaking such as this has massive local and national benefits, the need for support from the Estate Managements and Local and National Government is essential. This is specifically critical since funding received from most external agencies is limited and usually follows a “project’ approach where work comes to a standstill when monies are spent. The approach is also limited in terms of time since in this case NSRC had only one year to restore the Lake watershed. One can appreciate that even in ideal circumstances the transformation of a degraded natural environment is difficult since there are many factors involved. To give it a finite time line makes the task not only more difficult but also counterproductive since, just when the benefits begin to accrue, the work must end. The other challenge is the lack of clear policy on the use of agrochemicals in the immediate vicinity of water sources since little is understood about their impact on aquatic fauna and human health via the food chain. In this case, there is contamination of the streams that feed the Lake with agrochemicals, many of which produce and disseminate xenobiotics and their metabolites (Feron et al ., 2002). Given the emerging scientific evidence on the ecotoxicity of several agrochemicals, the question is: how can we protect our water resources when chemical pollutants are applied in their very source areas? The time has come to make a collaborative decision on our water resources.

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4.0 CONCLUSION Protection of urban lakes from external pollutants requires establishment of a buffer zone which should be aesthetically appealing and economically productive. Reestablishment of the buffer zone to meet the modern requirements will certainly require the approval of the local community who has been dependent on it for their livelihood for generation. The Landcare approach adopted in this study was proved to be effective, however, the sustainability depends on the participation of the stakeholders, the local government officials in particular. The overall effectiveness of the buffer zone including pollution control and economic benefits should be assessed in the long run.

5.0 REFERENCES Feron, V.J.C., Fleming R, Groten, John, P; Van Vliet, Petronella W; Zorge, Job, A., 2002, 'International Issues on human health Effects of Exposure to Chemical Mixtures', Health Perspect , vol. 110, no. Suppl. 6, pp. 893-9. Kumarihamy, Kumudeni, 2012, Personal communication Lockie, S 1999, 'Community Movements and Corporate Images: "Landcare" in Australia', Rural Sociology , vol. 64, no. 2, pp. 219-33. Tea Research Institute, SL 2008, 'Chemical Control of Weeds', TRI Advisory Circular , vol. PU 3, no. 05/08, p. 3. Wijewickrema, Hemasiri, 2009, a preliminary Report on the Landslides in the Lipton's Valley, NSRC Publication.

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URBAN LAKES IN STORMWATER MANAGEMENT OF AN URBAN CENTRE

WEIXiaohua, ZHANG Dongqingand TANSoon Keat

DHI-NTU Centre, Nanyang Environment and Water Research Institute (NEWRI) and Maritime Research Centre, School for Civil and Environmental Engineering, Nanyang Technological University, Singapore

ABSTRACT In this short paper, we present an innovative local stormwater containment design concept and a bio-filtration system for stormwater management near an urban water body In order to maximize the effectiveness of water quality control. The vertical wetland facilities have been viewed as a promising and low-cost alternate engineering solution for urban stormwater treatment. With smaller footprint and deeper penetration through the porous media, it is regarded as an appropriate flood mitigation facility in regions, and especially in urban centers including Singapore, that do not have sufficient space for a large-area constructed wetland. Keywords: stormwater management; urban centre; bio-filtration system.

1.0 INTRODUCTION Stormwater within an urban environment takes place when the drainage ancillary failed to discharge the runoff through the system and when that occurs it will always leads to flooding. There could be a number of reasons including 1) blockage of inlet or drainage channel or reduced capacity of the drainage ancillary, 2) drainage path deviates from that of the design path as a result of later change in catchment characteristics and 3) Insufficient capacity of the drainage system, the occurrence of extremely high intensity rainfall, several heavy rainfall events in quick successions, or arrival of several runoff peaks at the critical locations. Under normal circumstance and with proper management of design and construction activities, and maintenance of the drainage system, the above 1) and 2) are usually within the control of the authority whilst 3) is generally difficult to predict, and harder still with the evident change in climate and apparent increase in the number of occurrence of heavier intensity rainfalls. The case we can deal with is that flash flood arising from overflow or runoff amount that exceeds the local capacity. As a result, this excess water would find its own way and accumulate at the low points, a local depression or underground spaces. The accumulation of water, be it a local ponding of water or flooding, is at the least a nuisance and inconvenience, and more often than not, leads to economic losses, damage to property and infra-structure and possible loss of lives.

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For the purposes of the urban stormwater management, urban lak es are defined by six operational conditions [1]. First, they tend to be of a rather small surface area; second, they tend to be shallow, with an average depth of 2m or less. Third, they have a watershed area/drainage area ratio of at least 10:1, meaning t hat the watersheds exert a strong influence on the lake. Fourth, the lake watershed must contain at least 5% impervious cover as an overall index of development. Fifth, whether natural or man -made, the lake must be managed for recreational, water supply, f lood control or some other functions that directly support human activities. Finally, our definition excludes several types of lakes with unique hydrology or nutrient cycling. These include solution lakes that are strongly influenced by groundwater, the rare nitrogen-limited lakes, saline lakes and playa lakes. While these lake types can be found in urban areas, it is not clear whether they share the same quantitative and water quality response to watershed development as other freshwater lakes.

2.0 INNOVAT IVE METHOD FOR STORMWATER MANAGEMENT IN AN URBAN CENTRE 2.1 Quantitative Consideration There are pragmatic engineering solutions including pumping and erecting local protection such as flood barrier, which may sometimes be not possible readily, especially if the incidence takes place at unexpected locations. Nevertheless, these are active responses that require energy, manpower and resources. Modern designs now consider various means to reduce peak discharge through innovative considerations and implementa tions schemes along the different elements/pathways of a storm drainage system. A schematic sketch of the drainage elements and pathways is shown in Figure 1.

Receptor

Figure 1: Concept of source – pathway – receptor [2] 120

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In addition to conventional drainage design, one should include appropriate design for flash flood. The design should be based on passive approach that includes sacrificial flood basin – analogous to a flood plain, and where possible, effective runoff retention and stora ge facilities. Such large facilities could be found, for examples, in Tokyo and Hongkong, see Figures 2 and 3, respectively. Figure 4 shows a specially designed water retention basin in Sweden, which is used as part of the stormwater system to retain runo ff during heavy storms.

Figure 2:Underground detention pond in Tokyo [3]

Figure 3: Underground flood water storage in Hong Kong [4] 121

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Figure 4: Concept of receptor – sacrificial pond in Malmo, Sweden [5] Many cities in Asia have in the urban areas, natural and artificial lakes. Such cities include Hanoi and Ho Chi Minh City in Vietnam and Kandy in Sri Lanka, for examples. Where the urban centres are less endowed, artificial water bodies are usually created . A good example is the Marina Reservoir in Singapore. Such urban water bodies need to be maintained, both to ensure effective stormwater retention function and drainage regulation as well as maintaining good water quality for aesthetic and add to quality living in urban centres. Figure 5 shows a picture of the Marina Reservoir in Singapore. With the city scape and appropriate landscaping, the urban water could serves as tourist spot as well as a water body for recreational activitirs, in addition to its ba sic function for flood mitigation and water storage.

Figure 5: Marina Bay with Marina Centre in the background [6]

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2.2 Water Quality Consideration As space is a premium in an urban centre, development of Vertical Wetland-like facilities with small footprint around urban lake is an efficient method for stormwater filtration and detention. There are a number of successful applications of bio-filtratio n, but also many poor outcomes owing to inappropriate methodology and practice, albeit due to poor understanding and misconception of bio-filtration. When used appropriately, bio -filtration systems have been found to be viable and sustainable as a passive and low-cost water treatment method. In addition to reducing the impacts of urbanization on catchment hydrology and improving water quality, a bio-filtration system could also have tangible and intangible benefits including 1) occupies an acceptably small footprint relative to their catchment (typically ranging from 2 - 4%, depending on climate); 2) is an effective pre-treatment for stormwater harvesting applications; 3) is attractive landscape features; 4) is a self -irrigating (and fertilising) garden; 5) provides habitat and biodiversity values; 6) is potentially beneficial to the local micro-climate (evapotranspiration and local cooling); and 7) may be integrated with the local landscaping and urban design (streetscape). Figure 6 shows a schematic sketch of a possible bio-retention system.

Figure 6: A conceptual sketch of a vertical wetland system that may be incorporated in a ground tank design

3.0 LOCAL CONTAINMENT DESIGN FOR FLASH FLOOD By definition, the amount of runoff that could not be accommodate d by the drainage system would flow overland and typically follow the path of the least 123

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resistance to local low areas. The severity of the flooding could be gauged by comparing the excess amount over the total runoff volume (up to design capacity), as depicted in Figure 7. While it may be large in other urban centres, this ratio may be small in Singapore. However, in the perception of the public, a shallow flood of ankle-deep water covering large area is disconcerting and alarming. A pragmatic solution is to study the terrain of the catchment carefully (using GIS and detailed DEM) to develop an appropriate 3-dimensional model of the catchment, and put in place designated areas as “sacrificial” flood receptacles. Naturally these spaces are located at lower elevation compared to the surrounding terrain.

Figure 7: A schematic representation of excess / flood volume The local low point or designated flood receptacle could be an open ground or recreational area, or an underground space that is reserved for emergency use. Figure 8 is a schematic sketch of an open area that could be used as a designated flood receptacle. The grade level could be purposefully set lower than the surrounding terrain, forming a depression which will naturally turn into a detention pond to collect flood water. The underground space could also be utilized as ground tanks to increase the storage capacity of the design.

Figure 8: A Schematic Sketch Of Designated “Flood receptacle” By virtue of its being in the lower elevation, the flood receptacle could also serve as a rain water harvesting area, flooding or not. In addition, such a storage 124

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capacity could be designed to act as detention pond as part of the conventional drainage system when the threat of flood is imminent. Runoff water could be siphoned from drainage channels when the water level in those channel exceeded a certain threshold level. The team would develop the methodology considerations for the new drainage design concept.

4.0 CONCLUSIONS Many literatures have developed comprehensive programs for storm water quality control including phosphorus and nitrogenwhich is achieving significant. In this short paper, we presented an innovative local storm water containment design concept, bio-filtration system for storm water management in an urban area.

5.0 REFERENCES [1] Schueler T. & Simpson J., Introduction: Why Urban Lakes Are Different. Urban Lake Management , 2001, 3(4): 747-750. [2] Source of information: http://www.ciria.org/service/current_projects/AM/ContentManagerNet/ContentDis play.aspx?Section=current_projects&ContentID=17061Access date: 10 April 2012 [3] Source of information: http://news.yahoo.com/photos/tokyo-s-gigantic-flood- prevention-system-1319761029-slideshow/Access date: 10 April 2012 [4] Source of information: http://www.dsd.gov.hk/others/HKWDT/eng/background.htmlAccess date: 16 Jan 2012 [5] Source of information: http://www.ciria.org/service/current_projects/AM/ContentManagerNet/ContentDis play.aspx?Section=current_projects&ContentID=17061 [6]Source of information: http://en.wikipedia.org/wiki/Marina_Bay,_SingaporeAccess date: 16 April 2012

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NUTRIENT REMOVAL IN TROPICAL SUBSURFACE FLOW CONSTRUCTED WETLANDS

Dong Qing Zhang 1*, Junfei Zhu b, Yifei Li 2, Richard M. Gersberg 3, Soon Keat Tan 2

1DHI-NTU Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore 2Maritime Research Centre, School of Civil and Environmental Engineering, Nanyang Technological University,Singapore 3Graduate School of Public Health, San Diego State University, USA

1.0 INTRODUCTION Constructed wetlands (CWs) have been considered and proved to be an attractive and stable alternative for wastewater treatment because of its low- cost, and energy-saving. In addition, there is the advantage of multi-purpose reuse of the high quality effluent, self-remediation and self-adaptation to the surrounding condition and environment (USEPA, 1993 & 2000). Operation of sub-surface flow (SSF) CWs (SSF-CWs) in batch-flow (BF) mode (alternating drain and fill cycles) is a strategy that may improve both nitrogen (N) and phosphorus (P) removal efficiency in wastewater wetlands (Burgoon et al., 1995; Stein et al., 2003). Wijler and Delwiche (1954) first proposed the idea that alternating periods of submergence and drying of soils might enhance N loss compared to a continuously flooded condition. They reasoned that alternating periods of aerobic and anaerobic soil conditions could facilitate the sequential coupling of nitrification and denitrification, with nitrate generated during the aerobic phase being denitrified in the anaerobic phase. The long-term mechanism of P retention in wetlands is the adsorption of orthophosphate onto the surfaces of soil minerals, particularly hydrous oxides of iron and aluminum (Richardson, 1985; Chambers and Odum, 1990) Therefore, if the rates of both sequential nitrification-denitrification and Fe oxyhydroxide formation in CWs are affected by oxygen supply, then in general, BF operation which promotes more oxidized conditions by mass flow of air into pore spaces, should exhibit better performance than continuous-flow (CF) operation. However, there is still uncertainty as to whether BF operation enhances removal efficiencies when compared to a CF regime. For example, Busnardo et al. (1992) evaluated nutrient removal efficiency by SSF wetlands operated in drain and fill mode, as compared to CM operation, and found that while P removal efficiency was enhanced by BF operation, it had a surprisingly small effect on N removal efficiency. Burgoon et al. (1995), evaluated both BF and CF SSF wetlands which received either primary or secondary wastewater, and found that while the presence of plants in these CWs had significant effects on Carbon (C) and N oxidation (presumably due to oxygen transport by the plants), 127

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periodic draining and filling of the wetlands did not have any significant effect on biochemical oxygen demand (BOD 5) or N removal. More recently, Stein et al. (2003) compared the performance of BF and CF wetlands filled with simulated wastewater, and found both superior N and P removal in batch mode operation. The objectives of the present investigation were to evaluate; i) the influence of BF versus CF mode on the removal efficiencies of chemical oxygen demand (COD), N, and P in tropical SSF-CWs, ii) the quantitative role of the higher aquatic plants in nutrient removal in these two alternative operational modes.

2.0 MATERIAL AND METHODS Six CW beds at the campus of Nanyang Technological University (NTU) were installed. The wetland beds were 120 cm long, 60 cm wide and 60 cm deep. Thickness of gravel bed was 0.30 m with 4-10 mm gravel (D 60 =3.5 mm). The porosity was 0.45. Three horizontal flow (HF) SSF CWs were planted with cattail ( Typha Angustifolia ) at a density of approximately 14-15 plant/m 2, and 3 beds without plant. The latter were used as “unplanted” control beds. The emergent macrophyte, Typha Angustifolia, had been cultivated for 3 years earlier and then established in the tanks for 2 months before the experiment. All the containers had a flat bottom and a 50 mm diameter and 0.4 m long horizontal drainage pipe at the lower edge of the containers. Prior to the experimental data were collected, all the beds were irrigated with wastewater from the secondary treatment process in wastewater treatment plants for two weeks, and operated with synthetic wastewater for four weeks. The operational modes included BF and CF systems. The comparison was made during two periods during which wastewater and environmental conditions were identical. Water depth was maintained at 5 cm below the gravel surface, and in the BF operation, the hydraulic application rate was maintained at 2.8 cm/day for a 4-day retention time. Artificial wastewater was rapidly filled in each bed, sampled at 2- and 4-day intervals, and then drained completely every 4 days and filled again. In contrast, the CF operation was operated at different retention times (2 days and 4 days) with hydraulic application rates of 5.6 cm/day and 2.8 cm/day, respectively. Holding tanks of 150 L capacity served as the reservoir for the source wastewater. CL was accomplished by using a six-channel peristaltic pump. Each channel was adjusted to a flow rate of 12.5 ml/min resulting in retention times of 4-days, and 25 ml/min resulting in retention times of 2-days. With respect to artificial wastewater preparation, analytical grade ammonium sulfate (98% purity), magnesium sulfate heptahydrate (99% purity), calcium chloride dehydrate (99% purity), calcium chloride ACS (74.0%-78.1% purity), Iron (III) chloride, anhydrous (98% purity), sodium carbonate (98% purity), sodium hydrogen carbonate (99% purity), potassium dihydrogen 128

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phosphate (98% purity) obtained from Alfa Aesar, Germany were used. The composition of influent included 300 mg/L COD (averaged), 27 mg/L NH 4-N, 7 mg/L PO 4-P, and Fe 4 mg/L, 7 mg/L Mg, and 6 mg/L Ca. Effluent samples were collected on the same day and at the same time, as well as collected from each bed every two and four days in a 1-L amber glass bottles, which were transported refrigerated (4°C) to the laboratory. The samples were immediately analyzed to determine the reduction in concentration + - of the general parameters, i.e., COD, ammonia-N (NH4 -N), nitrate (NO 3 -N), and total phosphorus (TP). General parameters were analyzed using spectrophotometer (HACH-DR3800, USA) in accordance with the standard methods (Standard Methods for Examination of Water and Wastewater - APHA, 1989). Temperature, dissolved oxygen (DO), pH value and electrical conductivity (EC) were measured using Multi-Parameter Digital Meter (HACH – HQ40d, USA) directly.

3.0 RESULTS AND DISCUSSION The effect of BF operation and CF operation on the removal of COD, ammonium (NH 4-N), nitrate (NO 3-N) and total phosphorus (TP) were evaluated. Table 1 shows the overall average effluent concentration and removal of the water quality parameter. BF operation of SSF-CWs has been proposed as a method for enhancing movement of air into the gravel pore spaces, and thereby stimulating the oxidation of C and N and removal (adsorption) of P. Our results obtained from comparing BF operation versus CF operation for a tropical SSF-CW, showed that while these alternative loading methods had no significant effect on C oxidation (COD removal), both N oxidation and P removal were significantly enhanced in the BF operation as opposed to CF mode operated at 4 day HRT. Table 1: Overall average effluent concentration, standard deviation and average removal (%) of the water quality parameter

Operation COD NH 4-N NO 3-N TP HRT Mode (mg L -1) (mg L -1) (mg L -1) (mg L -1)

2-day Planted 21.7±14.3 1.7±0.9 0.3±0.2 9.2±3.2 Removal (%) 92.6 93.7 58.0 Unplanted 30.5±21.2 14.5±4.5 0.3±0.2 13.9±4.8 Removal (%) 89.6 46.3 37.0 Batch 4-day flow Planted 12.4±12.2 1.3±1.0 0.2±0.1 6.7±2.3

Removal (%) 95.8 95.2 69.6 Unplanted 20.8±15.6 13.6±4.3 0.2±0.1 13.4±4.2 Removal (%) 92.9 49.3 39.1

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2-day Planted 26.5±20.6 8.4±2.7 0.6±0.5 15.4±5.3 Removal (%) 91.0 68.9 30.0 Unplanted 36.1±28.3 14.3±5.0 1.8±1.6 15.8±4.4 Continuous Removal (%) 87.7 47.0 28.2 flow 4-day Planted 12.0±8.4 5.3±1.7 0.2±0.1 12.1±3.8 Removal (%) 95.9 80.4 46.8 Unplanted 26.1±17.1 14.3±2.2 0.3±0.2 16.4±4.2 Removal (%) 91.1 47.0 25.5 3.1 COD Removal For the test series of 4-day retention time, there were no significant differences (p>0.05) for COD removal between batch and continuous flow modes for either the planted or unplanted treatments. The statistical results were the same for the 2-day HRT: there was no significant difference when the results for BF operation were compared to that for CF operation (Table 2). When effluent COD concentrations in planted versus unplanted beds were compared, significant differences (p<0.05) were observed only for those operated under CF mode at the 4-day HRT. These results are similar to those of Caselles-Osorio and García (2007a) who found that although intermittently fed wetlands operated under more oxidized conditions, there was no performance difference in COD removal as compared to continuously fed systems. However, as pointed out by Caselles- Osorio and García (2007a), intermittent operation (which does not involve complete draining of the wetlands) is not equivalent to BF operation which does completely drain then fill the wetlands. Apparently, whether intermittently fed or completely drained and filled, COD removal efficiencies are not enhanced when compared to CF systems. On the other hand, Caselles-Osorio and Garcia (2007b) found that the presence of plants clearly had a significant impact on the removal efficiency of COD, and attributed this impact to either the convective transport of oxygen, or indirectly to increased evapotranspiration (ET) rates which increased fluctuations in water levels (which in turn creates a more aerobic environment). However, surprisingly, in our SSF-CWs, COD removal was not significantly affected by the presence of plants in the BF operated wetlands. However, for the 4-day residence time in our CF wetlands, there was a significant (p< 0.05) difference between planted and unplanted beds, even though the difference in removal efficiency for the planted beds (95.9%) was only slightly better than that for the unplanted (91.1%). Our results then are in agreement with that of Tanner (2001), who compared side by side studies of planted and unplanted gravel-bed CWs and found that “in general, wetland plants provide only small improvements in BOD 5 and COD removal”. The reasons for this are unclear, but apparently are reflective of the fact that at least at the typical COD loading rates, the sum of the processes of aerobic (and anaerobic) organic carbon 130

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degradation acting solely in a gravel filter (with no plants) are sufficient to drive BOD 5/COD degradation to near completion without the need for either plant rhizosphere aeration or drain and fill operational. 3.2 N removal

Figure 1 shows the comparison of NH 4-N effluent concentrations between batch and continuous modes for the test series with 4-day retention time. In planted beds, statistical analysis showed that there was significant enhancement (p<0.001) of NH 4-N removal in BF mode operation (95.2%) as compared to CF mode operation (80.4%); while in unplanted beds, there was no significant difference (p>0.05) for batch flow (49.3%) as compared to the CF mode (47%). A similar conclusion was drawn for BF and CF operation at 2-day HRT. In addition, in both BF and CF operational modes, NH 4-N removal was significantly enhanced (p<0.001) in the planted beds as compared to the unplanted beds.

Planted beds at 4-day retention time Unplanted beds at 4-day retention time

10 25 Continuous Continuous 8 Batch 20 Batch

6 15

4 10 NH4-N (mg/L) NH4-N NH4-N (mg/L) NH4-N

2 5

0 0 0 10 20 30 40 50 60 70 80 90 0 10 20 30 40 50 60 70 80 90 Day Day

Figure 1: Comparison of NH 4-N effluent concentration between batch and continuous flow at 4-day retention time These results are in good agreement with Caselles-Osorio and Garcia (2007a) who found that intermittent feeding as compared with continuous feeding, provide a more “oxidized” treatment environment which in turn promoted a higher level of ammonium removal (on average 80-99% as compared to 71-85%). The presence of marcrophytes also enhanced removal of ammonium (on average 98% as compared to 73%). All these high removal efficiencies are significant, given that ammonium removal efficiencies in HF- SSF-CWs are reported at lower than 50% (USEPA, 2000). 3.3 TP removal Figure 2 shows the comparison of the TP effluent concentration between batch and continuous flow modes for the 4-day hydraulic retention time. For both planted and unplanted beds, there was significant enhancement (p<0.05) in

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TP removal in BF operation (69.6% for planted beds; 39.1% for unplanted beds) as compared to CF operation (46.8% for planted beds; 25.5% for unplanted beds). In addition, in both batch and continuous modes, planted beds showed significantly better TP removal efficiencies (p<0.001) than that in unplanted beds. However, for the test series of 2-day HRT, and in comparing the BF operation and CF operation, the statistical results showed significant differences only for the planted bed.

Planted beds at 4-day retention time Unplanted beds at 4-day retention time

25 25

20 20

15 15 TP (mg/L) TP 10 (mg/L) TP 10

5 Continuous 5 Continuous Batch Batch 0 0 0 10 20 30 40 50 60 70 80 90 0 10 20 30 40 50 60 70 80 90 Day Day

Figure 2:Comparison of TP effluent concentration between batch and continuous flow at 4-day retention time Figure 2 shows the comparison of the TP effluent concentration between batch and continuous flow modes at the 4-day retention time. For both planted and unplanted beds, there is significant enhancement (p<0.05) of TP removal in BF operation (69.6% for planted beds; 39.1% for unplanted beds) as compared to CF operation (46.8% for planted beds; 25.5% for unplanted beds). In addition, in both BF and CF operation modes, planted beds showed significantly better TP removal efficiencies (p<0.001) than that in unplanted beds. Stein et al. (2003) indicated that phosphate removal by BF operation is superior compared to CF operation. Any flux of dissolved oxygen produced either by radial oxygen flow away from the plant roots, or by drain and fill reaeration, may also react with Fe at the metal’s surface to convert it to hydrous ferric oxide (Busnardo et al., 1992). P is removed primarily by ligand exchange reactions, where phosphate displaces water or hydroxyls from the surface of Fe hydrous oxides (Vymazal, 2005). It is generally accepted that aerobic conditions are more favorable for P sorption and co-precipitation (Boström et al., 1982; Faulkner and Richardson, 1989). Breen (1997) showed that the ET rate caused level fluctuations on the batch-loaded system. These fluctuations exposed more granular medium to the atmosphere, thus promoting more “oxidised” conditions. Behrends et al. (1993) reported reaeration rates four 132

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times faster in drain and fill treatments than that in static controls, due to the rapid oxygenation of the wetted gravel that was exposed to air during the drain phase. This could plausibly explain our observations of significant enhancement (p<0.05) for TP removal in BF flow operation in the planted beds as compared to that in CF operation, and planted beds showed significantly better TP removal efficiencies (p<0.05) in BF operation than that in unplanted beds.

4.0 CONCLUSIONS The results of this study on BF versus CF operation modes for a tropical SSF-CW showed that while these loading methods had no significant effect on COD removal, both ammonia oxidation and TP removal were significantly enhanced in BF mode versus CF mode. At a 4-day HRT, the presence of plants significantly enhanced both ammonia oxidation and TP removal in both batch and continuous flow modes of operation as compared to that for unplanted beds. Estimation of the quantitative contribution of oxygen from batch (drain and fill operation) as compared to plant rhizosphere aeration from the differences in nitrification rates between BF versus CF and planted versus unplanted beds, leads to the conclusion that at the 4-day HRT used for this study, drain and fill cycling might only account for less than half of the plant’s quantitative contribution of oxygen. The findings of this study imply that where maximal N and P removal is desired, periodic draining and filling might be the preferred operational strategy for a full-scale SSF-CW.

5.0 REFERENCES APHA, 1989. In: Standard Methods for the Examination of Water and Wastewater (Clesceri, L.S.; Greenberg, A.F.; Trussell, R.R., eds). American Public Health Association. Barnes, D., Bliss, P.J., 1983. Biological control of nitrogen in wastewater treatment, EFN Spon, London, 1983. Behrends, L.L., Coonrod, H.S., Bailey, E., Bulls, M.J.,1993. Oxygen diffusion rates in reciprocating rock biofilters: potential applications for subsurface constructed wetlands. Proceedings Subsurface Flow Constructed Wetlands Conference. August 16-17. El Paso: University of Texas, 1993. Boström, B., Jansson, M., Forsberg, C., 1982. Phosphorus release from lake sediments. Arch. Hydrobiol. Beih.Ergebn.Limnol. 18, 5-59. Breen, P.F., 1997. The performance of vertical flow experimental wetlands under a range of operational formats and experimental conditions.Wat. Sci. Tech. 1997; 35(5):167-74. Burgoon, P.S., Reddy, K.R., DeBusk, T.A., 1995. Performance of subsurface flow wetlands with batch-load and continuous-flow conditions. Water Environ. Res, Vol.67 No.5.

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Busnardo, M.J., Gersberg, R.M., Langis, R., Sinicrope, T.L., Zedler, J.B., 1992. Nitrogen and phosphorus removal by wetland mesocosms subjected to different hydroperiods. Ecol. Eng. (1992) 287-307. Caselles-Osorio, A., García, J., 2007a.Impact of different feeding strategies and plant presence on the performance of shallow horizontal subsurface-flow constructed wetlands. Sci. Total Environ. 378 (2007) 253-262. Caselles-Osorio, A., García, J., 2007b. Effect of physic-chemical pretreatment on the removal efficiency of horizontal subsurface-flow constructed wetlands. Environ. Pollut. 146 (2007) 55-63. Chambers, R.M., Odum, W.E., 1990. Porewater oxidation, dissolved phosphate and the iron curtain; iron-phosphorus relations in tidal freshwater marshes. Biogeochemistry, 10:37-52. Diemont, S. A., 2006. Mosquito larvae density and pollutant removal in tropical wetland treatment systems in Honduras. Environ Int (2006) 32(3):332-41. Faulkner, S.P., Richardson, C.J., 1989. Physical and chemical characteristics of freshwater wetland soils. In: Hammer, D.A. (Ed.), Constructed Wetlands for Wastewater Treatment. Lewis Publishers, Chelsea, Michigan, pp.41-72. Henze, M., Harremoes, P., Jansen, J.C., Arvin, E., 1995. Wastewater treatment: Biological and chemical processes, Springer, Berlin, 1995. Jing, S.R., Lin, Y.F., Shih, K.C., Lu, H.W., 2008. Applications of constructed wetlands for water pollution control in Taiwan: review. Pract. Periodical of Haz., Toxic, and Radioactive Waste Mgmt. Volume 12, Issue 4, pp249-259. Richardson, C.J., and Nichols, D.S., 1985. Ecological analysis of wastewater management criteria in wetland ecosystems. In: Godfrey, P.J., Kaynor, E.R., Pelczarski, S. and Benforado, J. (Eds), Ecological Considerations in Wetlands Treatment of Municipal Wastewaters. Van Nostrand Reinhold Company, New York, pp.351-391. Stein, O.R., Hook, P.B., Biederman, Allen, W.C., Borden, D.J., 2003. Does batch operation enhance oxidation in subsurface constructed wetlands? Wat. Sci.Tech. Vol 48, No 5, 149-156. Tanner, C.C., 2001. Plants as ecosystem engineers in subsurface-flow treatment wetlands.Wat. Sci. Tech. 44(11-12):9-17. USEPA, 1993.Constructed Wetland for Wastewater Treatment and Wildlife Habitat. Office of Research and Development, EPA 832-R-93-005, Sep 1993. USEPA, 2000.Constructed wetland treatment for municipal wastewater.EPZ/625/R- 99/010. Cincinnat, OH: Office of Research and Development; 2000. 166pp. Vymazal, J., 2005. Horizontal sub-surface flow and hybrid constructed wetlands systems for wastewater treatment. Ecol. Eng. 25 (2005) 478-490. Wijler, J., Delwiche, C.C., 1954. Investigations on the denitrifying process in soil. Plant Soil, 55-169.

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DETERMINATION OF THE CURRENT STATUS OF WATER QUALITY IN SOME ECONOMICALLY IMPORTANT WATER BODIES IN SRI LANKA

S.A.M.Azmy,K.A.W.S.Weerasekara,N.D.Hettige, C. Wickramaratneand A.A.D.Amaratunga

Environmental Studies Division, National Aquatic Resources Research and Development Agency (NARA), Sri Lanka.

ABSTRACT This study focused to identify the current status of water quality in Giant’s Tank in Akurala water bodies and Puttalam Lagoon of Sri Lanka during the year 2011. In-situ analysis was conducted for the determination of pH, Dissolved Oxygen (DO), Turbidity, Electrical Conductivity (EC), Total Dissolved Solids (TDS) and Salinity. Laboratory analysis was carried out in accordance with the Standard Methods for Examination of Water and Waste Water (APHA), 20th edition. Results of the Puttalam Lagoon revealed that, pH, DO, chlorophyll-a and nutrient concentrations are within the accepted limits for the survival of fish and aquatic life. However, TSS (8.48 ± 4.22 mg/L), Turbidity (6.93 ± 2.60 NTU) and TDS (23.2 ± 2.74 mg/L) indicated slightly high values. Gaint’s tank indicated that DO, EC, Nitrate, Hardness, Alkalinity, Turbidity and BOD were within permissible levels proposed by the CEA, 2001.However the pH and phosphate level that fell slightly above the ideal pH range and maximum phosphate level for above the standards. Akurala water bodies revealed that, pH, and Nitrate, values were within the permissible levels. The phosphate (0.45 ± 0.18 mg/L) level was slightly above the maximum recommended values. Average values of DO (4.82 ± 0.37 mg/L), EC (630 ± 59.70 mS/cm), TDS (340.71±24.52 g/L), and Ammoniacal – N (0.24±0.15) were found.

1.0 INTRODUCTION Water quality parameters are important observation that would reveal the current conditions within a catchment and downstream waters. These data would assist in understanding the potential impacts on the system if there is any change in the conditions. Hence, this rapid assessment is an initial attempt to understand how the water quality of the system may be altered if the area is to be altered for commercial utilization. Rapid assessment, for the purpose of this guidance, is defined as: “a synoptic assessment, which is often undertaken as a matter of urgency, in the shortest time frame possible to produce reliable and applicable results for its defined purpose” (Anonymous, 2006). Giant’s Tank, with an area of 3941 ha is one of the largest and shallowest reservoirs located in the Mannar district which supports numerous economical

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activities within the area (Daily News, 2011).Giant’s Tank provides water to an irrigable land area of 24,438 ha and channels water to over 162 small tanks (Sunday Observer, 2008). Akurala is a coastal village in the Galle district which was once famous for its lime industry. The villagers have been engaged in mining both the seabed and the land side for lime stones for generations. A coastal lagoon system consisting of brackish water exists adjacent to the main road in Akurala. The system comprises of a large number of interconnected water bodies which expand over a vast area of around 30 ha. The tsunami event which took place in 2004 had a devastating effect on the coastal ecosystem, small farms and home-gardens. The Puttalam Lagoon and associated coastal areas on the north western coast of Sri Lanka (Latitude 7 0 45’- 80 25’N, Longitude 79 0 42’- 79 0 50’E) fall under the jurisdiction of the North Western Provincial Council. Though widely referred to as a lagoon, the Puttalam Lagoon technically is an estuary.The Puttalam Lagoon is open to the sea at the northern end of the Puttalam Lagoon. The only input of fresh water from riverine sources to the estuarine system is by two rivers Mi Oya and Kala Oya, of which both discharge into the Puttalam Lagoon (Dayaratne et al., 1997). The main objective was to study the current status of water quality to identify the aquatic health of selected eco systems such as Puttalam Lagoon, Giant’s Tank in Mannar and Akurala during the year 2011.

2.0 METHOD The following physico-chemical parameters were selected for this study to ascertain the quality of water and to ascertain changes and effects. In-situ analysis were conducted for the determination of pH, which was measured using a pH meter (Orion 260A), electrical conductivity (EC), measured using Hanna portable multi range conductivity meter (HI 8733), Dissolved Oxygen (DO) concentration, measured using a portable meter (Orion 830A), and Turbidity, measured using portable meter (Hach 2100P). In addition, EC, Total Dissolved Solids (TDS) and salinity were measured at the site, during the time of sample collection. Furthermore, laboratory analysis was carried out in accordance with the Standard Methods for Examination of Water and Waste Water (APHA), 20th edition.

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3.0 RESULTS AND DISCUSSION 3.1 Giant’s Tank. Table I: Overall result for all sampling locations in the Giant’s Tank. Parameter Min Mean Max Stdv. Water Temp ( oC) 27.3 28.5 30.0 0.96 pH 7.87 8.48 8.76 0.39 DO (mg/L) 5.40 6.76 7.82 1.08 BOD (mg/L) 18 24 30 3.21 EC (uS/cm) 711.00 791.86 979.00 124.17 TDS (mg/L) 344.00 385.43 480.00 62.99 Salinity (ppm) 0.30 0.37 0.50 0.10 Turbidity (NTU) 9.67 50.08 117.00 43.46 Ammonia (mg/L) 0.24 0.42 0.63 0.16 Nitrate (mg/L) 0.08 1.95 6.84 2.58 Phosphate (mg/L) 0.43 0.87 1.44 0.40 TSS (mg/L) 3.60 31.71 66.00 24.82 Alkalinity (mg/L) 95.00 112.14 140.00 19.55 Chloride (mg/L) 102.81 134.20 166.62 23.55 Total Hardness (mg/L) 200.00 238.29 303.00 42.80 Calcium Hardness (mg/L) 16.03 34.30 70.54 19.83

The pH measured in the samples collected from the Giant’s Tank reflected values that fell slightly above the ideal pH range proposed by the Central Environmental Authority (CEA) for fish and aquatic life (Figure 1). Eriyagama (1961) states that much of the Mannar District is composed of soils that are sandy clay to sandy clay loams with concretions of carbonates of calcium, sodium, and manganese oxide. The above could be one of the reasons for the higher pH values recorded within the water body. The DO values obtained from the Giant’s Tank samples were higher than the minimum DO concentration required for aquatic life as proposed by the CEA at most of the sites, mainly due to strong water currents. The less DO concentrations at sample points 1 and 10 could be due to the water bodies being separated from the main reservoir and thereby, being stagnant.

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9 8.5 8 7.5 7 6.5 6 5.5 5 1 2 3 4 5 6 7 8 9 10 Sample Ideal pH pH DO (mg/L) Min DO (mg/L) Figure 1: pH and DO Variation of Giant’s Tank EC is a measure of the ability of water to conduct an electric current and can be affected by the concentration of the ions, temperature of the solution, and the specific nature of the ions (McCleskey, 2011). Determination of EC is a rapid and convenient m eans of estimating the concentration of ions in solution. Since each ion has its own specific ability to conduct current, EC is only an estimate of the total ion concentration. EC is an approximate indicator of TDS and hence, the variations observed in EC can be explained to a greater extent through the variation in TDS concentrations. The above is true for the samples collected from the Giant’s Tank as illustrated in Figure 3 [discussion for Figure 2 should come first], where the correlation (R 2) between the two variables is found to be0.748 and therefore, it can be stated that the reason for the higher EC measured is the presence of high TDS.

Figure 2: EC and TDS values for the samples

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Figure 3: Relationships between EC and TDS. - 3- The nitrates (NO 3 ) and phosphates (PO 4 ) were estimated in the samples collected in order to assess the enrichment of the water within the reservoir as the surrounding area of Giant’s Tank consists of agricultural land and therefore, may result in nutrients loading into the reservoir system. The results depict that - the NO 3 concentrations, except for the level observed at sample point 2, are well below the maximum NO 3- concentration defined by the CEA as the 3- suitable level for aquatic life. The PO 4 concentrations were almost in align 3- with the guidelines except for the slightly high levels of PO 4 concentrations observed from sampling points 1-5. The reason for the above observed high concentrations of nutrients could be the presence of increased aquatic plants or the adjac ent forest areas which would have high inputs of organic matter into the reservoir during runoff. 3.2 Akurala Water bodies Table 2: Overall results for all sampling points in the Akurala water bodies Parameter Min Mean Max Stdv Water Temp ( oC) 26.9 30.5 32.4 2.29 pH 7.89 8.05 8.31 0.15 DO (mg/L) 4.44 4.82 5.31 0.37 EC (uS/cm) 5400 6300 7100 597 TDS (mg/L) 2970 3407 3770 245 Salinity (ppm) 3.00 3.50 3.90 0.28 Turbidity (NTU) 4.76 6.96 9.51 1.81 Ammonia (mg/L) 0.15 0.24 0.58 0.15 Nitrate (mg/L) 0.02 0.25 0.31 0.10 Phosphate (mg/L) 0.17 0.45 0.69 0.18

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The pH measured in the samples collected from Akurala reflected values that were within the ideal pH range proposed by the CEA for aquatic life (Figure 4). The presence of brackish water and the presence of lime sources in the area also may be influencing the close to 8 pH values observed in the water samples. The DO values obtained from the Akurala samples were lower than the minimum DO concentration required for aquatic life as proposed by the C EA at most of the sites. This could be due to inadequate internal mixing and the presence of large amounts of organic matter.

Figure 4: pH and DO Variation of Akurala The measured TDS and EC values exceeded the maximum guidelines proposed by the CEA. How ever, this could be due to the higher number of ions present in salt water and the presence of limestone in the bed rock which leads to higher EC because of the dissolution of carbonate minerals. Turbidity expresses the opaqueness of water and can be affec ted by the presence of TSS. Hence, the high TSS levels could result in increased turbidity readings and are influenced by the particle size and shape of suspended solids, the presence of phytoplankton, the presence of dissolved humus and the presence of di ssolved mineral substances (Bilotte and Brazier, 2008). The reason for turbidity observed at sample points could be due to the presence of organic matter. - The results depict that the NO 3 concentrations are well below the - maximum NO 3 concentration defined by the CEA as the suitable level for 3- aquatic life. The results also depict that the PO 4 concentrations, except for the 3- level observed at sampling point 6 and 7, are slightly high levels of PO 4 concentrations defined by the CEA as the suitable level for fish and aquatic life.

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3.3 Puttalam Lagoon Table 3: Overall results for all sampling points in the Puttalam Lagoon Parameter Min Avg Max Stdv Water temp ( oC) 21.3 31.0 32.6 2.3491 pH 8.14 8.18 8.29 0.0342 DO (mg/L) 6.32 6.89 8.31 0.4762 EC (mS/cm) 31.50 37.99 44.90 4.0579 Ammonia cal-N (mg/L) 0.11 0.44 0.71 0.2147 Nitrite-N (mg/L) 0.00 0.01 0.05 0.0159 Phosphate (mg/L) 0.01 0.23 1.61 0.3815 TSS (mg/L) 2.00 8.48 17.60 4.2224 Turbidity (NTU) 2.66 6.93 13.42 2.6095 TDS (mg/L) 18.82 23.20 27.90 2.7484 Salinity (ppm) 19.60 24.13 29.10 2.8823 Chlorophyll -a (mg/m 3) 0.35 3.70 19.28 4.3835

In general, pH values of the selected sampling locations in the lagoon were ranging from 8.14 to 8.29 and with the mean pH value of 8.18. The pH levels are in accordance with the standard pH given for fish and aquatic life, as stated by the Sri Lanka Standard Institute. Although the suitable pH range for the existence of biological life is typically between 6 to 9, pH values above 8.5 are often caused by bicarbonate and carbonate concentrations known as and therefore, are considered to be alkaline. Water temperature in the lagoon was ranging from 21.30 0C to 32.60 0C and the overall, average water temperature in lagoon is 31.0 0C. DO is in fact essential for the survival of all aquatic organisms. Moreover, oxygen affects a vast number of other water indicators, not only biochemical but aesthetic characteristic like odor, clarity and taste. The mean DO concentration in the lagoon is 6.89 mg/L. When compared with the standards published by the Sri Lanka Standard Institute [similar comment as above], DO concentrations recorded in the sub catchment are within the acceptable limits for fish and aquatic life.

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Figure 5: DO and Water Temperature variation in the Puttalam Lagoon Results revealed that, the mean turbidity value was 6.93 ± 2.60 NTU and the recorded turbidity value varied between 2.66 NTU to 13.42 NTU. T he TDS in the lagoon varied between 18.82 mg/L to 27.90 mg/L and the mean value was 23.2 ± 2.74 mg/L. The results revealed that, the light penetration in the lagoon is very poor. Also, the amount of aquatic flora and fauna including chlorophyll-a, sea weed s and other dead material deposited at the bottom of the lagoon. Therefore, the decomposition rate in the bottom is very low.

Figure 6 : Variation of Turbidity & TDS in the Puttalam Lagoon 142

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The Puttalam lagoon has a recorded mean phosphate concentration of 0.23 ± 0.381 mg/L. Where the absolute values ranged from 0.01 mg/L to 1.61 mg/L. Average ammonia nitrogen concentration was recorded as 0.44 ± 0.21 mg/L and maximum ammoinacal nitrogen concentration was recorded as 0.71 mg/L. The average nitrite concentrations were determined as 0.01 ± 0.015 mg/L. The nitrite concentrations were low compared to the WHO recommended levels, and the levels recommended by the Sri Lanka Standard Institute portable water quality standard. In addition nutrient concentrations recorded indicated that nutrient in the Puttalam lagoon are generally within the acceptable limits for fish and aquatic resources compared to the draft national standard for fresh water quality published by the CEA. The study revealed that, there were elevated levels of chlorophyll–a concentration at the sampling sites (average value of 3.70 ± 4.38 mg/m 3).

4.0 CONCLUSIONS Results of Giant’s tank indicated that most of the water quality parameters such as DO, EC, Nitrate - N, Hardness, Alkalinity, and Turbidity [never discussed BOD results] were either slightly above or in align with the ideal range or the maximum levels proposed by the CEA as the ambient water quality standards for the aquatic life in the inland waters of Sri Lanka. However, the pH and phosphate level were slightly above the ideal pH range and maximum phosphate level for above the standards Results of the Akurala water bodies revealed that, pH and Nitrate- N, were within the ideal level proposed by the CEA for fish aquatic life. However, the phosphate level was slightly above the maximum recommended values refer to the above standards. According to the results of Puttalam Lagoon, water quality parameters including pH, DO levels, Chlorophyll-a and nutrient parameters are within the accepted limits for the fish and aquatic life. However, TSS , turbidity and TDS concentrations showed considerably high values. Therefore, it will impact to aquatic fauna in the lagoon. Also, in some places high chlorophyll-a values and dissolved phosphate concentrations were recorded reflecting meso-trophic conditions.

5.0 RECOMENDATIONS The proposal to initiate eco-tourism or education centres based on the Giant’s Tank. The proposal to initiate re-habilitation and utilization based on Akurala area such as a water related theme park should be reconsidered as the particular ecosystem may be vulnerable to additional developments.

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The environment around the study area show very good quality and reports of Dolphins and Dugongs are frequently sited in the Puttalam lagoon. So that, the potential for developing the areas around the Puttalan Lagoon islands could be considered. The Eco-tourism activities could be bird watching, trekking, marine mammal watching (Dolphins, whales, Duguongs etc.), tranquil holidays, zero carbon foot prints, sea angling, mangrove and coral reef viewing, scuba diving & sport fishing. It should be noted that the following results are based only on a rapid assessment survey, it would not give a thorough idea of the system which could be subjected to seasonal and other numerous environmental changes. Hence, it is recommended that a comprehensive study during a minimum of one year period.

6.0 ACKNOWLEDGEMENT The authors are thankful to National Aquatic Resource Research and Development Agency for providing funds to carry out this rapid assessment surveys.

7.0 REFERENCES APHA, 1998, Greenburg A.E., Rhodes T.R., and Lenore S.C. Standard Methods for the Examination of Water and Waste water, 20th edition, APHA/AWWA/WEF Bilotta, G. S. and Brazier, R. E. 2008.Understanding the influence of suspended solids on water quality and aquatic biota. Water Research 42 (1), pp. 2849-2861. Eriyagama, G.J. 1961. The semi-arid vegetation in Mannar region. The Ceylon Forester 5 (1), pp. 66-74. Siriweera, W.I. 2011. Heritage of Sri Lanka: Marvels of irrigation technology. Daily News, 11th May. URL: http://www.dailynews.lk/2011/05/11/fea03.asp (Assessed on 3/06/ 2011). Yatawara, D. 2008. Brightening the green: ‘Rice Bowl’ sows the seeds of hope, Sunday Observer, 6th July. URL: http://www.sundayobserver.lk/2008/07/06/sec10.asp , (Assessed on 3/06/ 2011). Dayaratne P., Linden, O., and De Silva, M.W.R.N. 1997. The Puttalam /Mundel estuarine system and associated coastal waters: Environmental Degradation, Resource Management Issues and Options for their Solution. NARA, Colombo, Sri Lanka.

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ASSESSMENT OF CAUSES FOR FREQUENT OCCURRENCES OF FISH KILL INCIDENTS OF SRI LANKA WITH SPECIAL REFERENCE TO WATER QUALITY

K.A.W.S.Weerasekara,S.A.M.Azmy,N.D.Hettig, Wickramarathne, C., Amarathunga A.A.D., Heenatigala P.P.M. and Rajapakshe, W.

National Aquatic Resource Research and Development Agency (NARA), Sri Lanka.

ABSTRACT The objective of this study was to investigate the fish kill incidents occurred in different aquatic environments and identify the causes of pollution.

Beira Lake, Diyawannawa Oya, Siyabalagamuwa Wewa, Thalan Lagoon and Pamunuwila Canal, were selected for this study from January 2011 to January 2012. Water quality analyses wereconducted following the Standard Methods for Examination of Water and Waste Water (APHA), 20th edition.

Results revealed that, Dissolved Oxygen (DO) concentration of water in Thalan Lagoon and Diyawannawa Oya were below the acceptable limits for survival of fish and aquatic life. Siyabalagamuwa wewa indicated Ammonical-N, pH, Biochemical Oxygen Demand (BOD), Total Dissolved Solids (TDS), and Turbidity levels which did not comply with the standard limits. Furthur, Epizootic Ulcerative Syndrome (EUS) disease condition recorded in fish observed in Siyabalagamuwa wewa and Thalan Lagoon.

Average Chlorophyll-a and phosphate concentrations of two fish kill incidents investigated in Beira Lake ranged from (20.06 ± 1.37µg/L) to (21.03 ± 0.50 µg/L) and from (0.337 ± 0.11 mg/L) to (0.651 ± 0.33 mg/L), respectively showing eutrophic conditions. Further, it has been identified that, fish did not indicate any external lesions leading to speculate that the mortality was due to any disease condition.

pH, phosphate and Electrical Conductivity (EC) levels which exceed the standard limits were identified as the cause of the fish kill for Pamunuwila Canal.

1. INTRODUCTION A ‘fish kill’ is a significant and sudden death of fish or other aquatic animals such as crabs or prawns. Such events are characterized by large numbers of aquatic animals dying over a short time, usually in a clearly defined area (Anonymous, 1998). Fish kills are important signs of environmental stress and it is important to investigate fish kill incidents to determine the cause. Identifying the cause of fish kills helps fisheries researchers and the public, as they may indicate significant environmental changes, to recognize disease conditions and water pollution events. 145

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Therefore, the main objective of this study was to investigate the fish kill incidents occurred in different aquatic environments and identify the cause of pollution and to propose recommendations to avoid such fish kill incidents in future.

2. METHOD Seven fish kill occurrences in six water bodies were investigated from January 2011 to January 2012 including Beira Lake, Diyawannawa Oya, Siyabalagamuwa Wewa, Thalan Lagoon and Pamunuwila Canal, Kelaniya. In-situ analysis was carried out to measure pH, Water Temperature, Dissolved Oxygen (DO), Electrical Conductivity (EC) and Turbidity, whereas - laboratory analysis was carried out to determine Nitrate-N (NO 3 - N), Nitrite-N - (NO 2 -N), Ammoniacal-N (NH4+-N), Phosphate, Biochemical Oxygen Demand (BOD), and Chlorophyll-a concentrations. For laboratory analysis, samples were stored at 4 0C and transported to the laboratory. All water quality analyzes were carried out in accordance with the Standard Methods for Examination of Water and Waste Water (APHA), 20th edition. Microsoft Excel 2007 was used as a data analysis tool to identify the water pollution status. Proposed Central Environmental Authority (CEA) ambient water quality standard for inland waters in Sri Lanka (2001) was used as standard guidelines for fish and aquatic life.

3.0 RESULTS AND DISCUSSION 3.1 Beira Lake Two fish kill incidents of Beira Lake were investigated during the months of October and December. The results of the both fish kills indicated that high chlorophyll-a , phosphate, turbidity, TDS and BOD values and low DO concentrations. Average chlorophyll-a and phosphate concentrations of two fish kill incidents investigated in Beira Lake ranged from (20.06 ± 1.37 µg/L) to (21.03 ± 0.50 µg/L) and from (0.337 ± 0.11 mg/L) to (0.651 ± 0.33 mg/L), respectively showing eutrophic conditions according to accepted boundary values ( OECD, 1982) . During the dry seasons, as algae growth on the lake's surface level increased almost every year, together with garbage and sewage, causes the algal bloom resulting in greenish colour of the water surface. The dead algae, may release toxins leading to fish mortality. This is most probably due to nutrient enrichment in dry weather periods resulting in low oxygen levels, especially during the nights and early morning periods. 146

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Results also indicated that low DO levels (2.79 ± 0.417 mg/L), high turbidity (20.12 ± 6.601 NTU), TDS (39.60 ± 3.219 mg/L), and BOD (15.33 ± 3.786 mg/L), levels during the fish kill investigations showing deterioration of water quality in the Beira Lake. 3.2 Diyawanna oya Low DO levels, which is below the acceptable limits for survival of fish and aquatic life and high levels of salinity, EC, turbidity, ammoniacal – N, phosphate and BOD values were observed by the fish kill incident investigation done during the month of June. EC (15.06 ± 6.802 mS/cm) and salinity (11.83 ± 6.948 ppt) levels indicated high values possibly due to salt water intrusion through the canal connected to Diyawannawa Oya during high tide period. 3.3 Siyabalagamuwa Wewa Siyabalagamuwa wewa indicated Ammonical-N, pH, BOD, TDS, and turbidity levels which did not comply with the standard limits (Table I). Table 1: Results of the water quality parameters measured on site Parameter SG 1 SG 2 SG3 Avg. Stdv. pH 9.05 8.66 8.71 8.81 0.212 DO (mg/L) 4.3 5.98 4.29 4.86 0.973 EC(mS/cm) 515 511 503 509.67 6.110

Turbidity (NTU) 18.09 7.65 8.04 11.26 5.918

- Nitrate(NO 3 - N) mg/L 0.03 0.07 0.06 0.05 0.021 - Nitrite(NO 2 -N) mg/L 0.008 0.021 0.053 0.03 0.023 + Ammonia(NH 4 -N) mg/L 0.06 0.06 0.03 0.05 0.017

3- Phosphate(PO 4 ) mg/L 0.01 0.04 0.04 0.03 0.017 TDS (mg/L) 249 247 244 246.67 2.517

Salinity (ppt) 0.2 0.2 0.2 0.20 0.000

BOD (mg/L) 5 5 5 5.00 0.000 Chlorophyll-a (µg/L) 2.52 0.71 4.53 2.59 1.911

Alkalinity (mg/L) 5 2.5 2.5 3.33 1.443

Chloride (mg/L) 88.63 70.9 65.58 75.04 12.069 Total Hardness (mg/L) 157 137 139 144.33 11.015

The pH measured in the samples collected from the Siyabalagamuwa Wewa during and after fish kill period reflected values that fell above the ideal pH range proposed by the CEA for fish and aquatic life (Table I). 147

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The disease that suspected as Episootic Ulserative Syndrom (EUS) were observed in collected dead fish samples from the site (Figures 1 and 2). According to the community, different fish species are living in the tank but dead fish species were mainly limited to the Etroplus suratensis (Korali). Few number of dead Labeo rohita (Rohu) also observed with same disease symptoms. All were died with closed mouths. Information gathered from the community in the vicinity, the fish kill had been occurred within a period of one week.

Figure 2:Dead specimen of Etroplus suratensis showing reddening of the skin

Figure 3: Dead specimen of Etroplus suratensis showing skin lesions

Since live fish samples were not available at the time of visit, the preserved fish samples were taken for the investigation. Scale losses, hemorrhages, lesions and ulcers were visible in those samples and the lesions were mainly observed closer to the mouth and tail. In some fishes deep lesions were observed and bones also visible.

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3.4 Thalan Lagoon Results of the water quality of Thalan Lagoon indicated low pH (6.38 ± 0.156), and DO (2.57 ± 0.289 mg/L), values which did not comply with the standard limits proposed by the CEA for inland aquatic life. In addition, high ammonia values were observed in some selected sampling locations in the site showing the average value of (0.47 ± 0.365 mg/L).The highest ammonia value was 0.734 mg/L. Fish samples were collected from the sampling site and infected samples were analyzed and observed. Clinical symptoms were necroric errotions in the trunk regions, haemorrhages near the base of the fins and mouth regions (Figure 3). Heavy infections were recorded in Godaya (Mugil cephalus ). Secondary infections were identified with fungus.

Figure 4: Haemorhagic lesions in the base of the pelvic fin of Mugil cephalus This fish mortality could be happened due to water pollution conditions prevailed in the lagoon and minimum water circulation in Dunkolawatta –Ela has obstructed by stabilizing Ja –kotu, Sluice gate creating the lagoon as stagnant water body.

3.5 Pamunuwila Canal, Kelaniya.

PH (4.28 ± 0.191), phosphate (0.97 ± 0.078 mg/L) and EC (819.50 ± 40.305 uS/cm) levels which exceed the standard limits for survival of fish and aquatic life were observed during the investigations done for the identify the cause of fish kill incident at the Pamunuwila Canal , Kelaniya. The samples taken from the site recorded a pH value close to 4 indicating that the water is highly acidic. The abnormal pH range could be due to the ingression of an acidic substance into the waterways with the rainfall events that took place prior to the fish kill event. The phosphate levels too at the sample points were higher than the standard levels. But there were no visible algal blooms or other eutrophication related factors observable at the study site.

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Table 2: Identified causes for the fish kill occurrences and Remedies proposed Water Body Causes Remedies Beira Lake Ammonical-N, BOD and the Identify water pollutant sources phosphate levels at some through proper monitoring locations did not comply with programs. the standard limits. Eutrophic conditions might be Actions should be taken to reason for this situation prevent further damage to the water bodies. Proper management and maintenance of the water body. Diyawannawa Oya Low dissolved oxygen levels in Avoid discharging effluents into the water which is below the water bodies which do not acceptable limits for survival of follow the guidelines and fish and aquatic life. general standards limits for discharge of effluents into inland surface waters using High levels of salinity, EC, recommended dilution factors. Turbidity,Ammonia,phosphate and BOD. Siyambalagamuwa Ammonical Nitrogen, pH, Control of EUS in natural waters Reservoir BOD, TDS, Turbidity levels is probably impossible. In which did not comply with the outbreaks occurring in standard limits for the survival small,closed water bodies, limits of fish and aquatic life liming of water and improvement of water quality, together with removal of infected fish, is often effective in reducing mortality. The disease is suspected as Enforce existing environmental Episootic Ulserative Syndrom regulations to overcome (EUS). discharge of sediments and pollutants by anthropogenic activities in the area Thalan Lagoon Stagnant water body and zero Actions should be taken to water circulation facilitate better water circulation. The levels of pollution owing to Increase awareness of people the increase of unionized about best land use practices in ammonia, low DO and nitrite the catchment. has resulted pathological effects in the gill tissue. EUS (Epizootic Ulcerative Syndrome) was identified. Pamunuwila Canal pH,Ammonia,Phosphate which Frequent fish kills would be did not comply the standard happened during the peak of the limits for fish and aquatic life. dry season and onset of rains regularly unless proper measures are taken to reduce the nutrient enrichment due to waste discharges. 150

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4.0 CONCLUSIONS It can be concluded that deterioration of water quality due to various anthropogenic activities and the absence of proper monitoring programs to ascertain the current status of water bodies are the main causes of most of the fish kill incidents.

5.0 RECOMMENDATIONS Water pollutant sources, should be identified through proper monitoring programs and actions should be taken to prevent further damage to the water bodies. Frequent fish kills would happen during the peak of the dry season and onset of rains regularly unless proper measures are taken to reduce the nutrient enrichment due to waste discharges. Prevent discharging effluents into water bodies which do not follow the guidelines and general standards limits for discharge of effluents into inland surface waters using recommended dilution factors. Report as soon as possible suspected outbreaks to relevant authorities to take immediate action to identify the cause of fish kill and take remedial measures.

6.0 ACKNOWLEDGEMENT The authors are thankful to National Aquatic Resources Research and Development Agency (NARA) for providing funds to conduct this study.

7.0 REFERENCES Anon. 1998, Fish kill reporting and investigation manual,Department of Environment and Heritage, URL: http://www.derm.qld.gov.au/register/p00366aa.pdf , (Assessed on 08/05/ 2012). APHA.1998, Greenburg A.E., Rhodes T.R., and Lenore S.C. Standard Methods for the Examination of Water and Waste water, 20th edition, APHA/AWWA/WEF Central Environmental Authority. 2001, Proposed Ambient Water quality Standards for Inland Waters Sri Lanka. Colombo, Sri Lanka: Environment Action 1 Project (Funded by ADB). OECD. 1982, Eutrophication of Waters: Monitoring, assessment and control. Organization for Economic and Co-operative Development, Paris, France.

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AGRICULTURE AND WATER POLLUTION: A STUDY IN CATCHMENT OF LAKE GREGORY AND AGRICULTURAL AREAS IN NUWARA ELIYA

H.P. Henegama 1, N.D.K. Dayawansa 2, Saliya De Silva 3

1 Post Graduate Institute of Agriculture, University of Peradeniya 2 Department of Agricultural Engineering, University of Perdaeniya 3 Department of Agricultural Extension, University of Perdaeniya

ABSTRACT This study was carried out with the objective of assessing the agricultural activities taking place within the Gregory lake catchment and surrounding agricultural areas to identify their threats on the soil and water environment in general and specifically on the lake. Questionnaire survey was conducted within the Gregory lake catchment and surrounding areas of Nuwara Eliya to assess the agricultural practices, fertilizer and agrochemical usage by the farmers using 50 households who are directly or indirectly engaged in agriculture. Satellite images were analyzed to assess the land use changes of the Gregory lake catchment and to identify the morphological changes in Gregory lake during 1992 and 1998. The results revealed that farmers tend to apply overdoses of fertilizers and pesticides to their crops aiming high economic gains. In addition, very steep slopes and riparian areas of the streams are used for cultivation posing threat on water resources. According to the study, the cultivated area in the lake Gregory catchment has increased approximately by 10% in 1998 compared to 1992. In addition, morphological changes in the lake also has occurred with time. Changes in the water surface area are mainly attributed to the sedimentation and aquatic plant growth. Dredging of sediments to restore lake environment has become a huge economic burden and is a temporary solution to the prevailing problems. Considering the nature of agricultural practices and land management aspects in the area, it is recommended to further investigate the over application of fertilizers and pesticides in agriculture and identify sustainable solutions through capacity building of farmers.

1. INTRODUCTION Agriculture is one of the major causes of degradation of surface and ground water resources through erosion and chemical runoff (FAO, 2011). Since Sri Lanka is an agricultural country, the chances of water sources being contaminated due to agricultural activities are very high (Dayawansa, 2006). For several decades, farmers are applyingoverdoses of fertilizers and pesticides (Mubarak, 2000) in intensive agricultural areas in Sri Lanka. It is revealed that theses excess fertilizers and pesticides, which are added into the environment, can easily contaminate surface and ground water sources (US EPA, 2009). As 153

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stated by Amarasiri (2007) the use of large amounts of nitrogenous fertilizers has lead to the development of high levels of Nitrate in water, exceeding the 50 mg/L- safe limit stipulated by many counties. Loss of Phosphorous (P) from intensively cultivated soils is one of the major causes of reducing water quality (Amarawansha and Indraratne, 2010). According to Dayawansa (2006) nitrate due to over application of nitrogen containing fertilizers is the second most common and widespread contaminant in many parts in Sri Lanka. According to Mubarak (2000) the most common pesticides used by the Sri Lankan farmers are Proponil and MCPA. Wijewardena (1998) revealed that the drinking water could be polluted by plant nutrients due to intensive agricultural activities in upcountry of Sri Lanka. Sri Lanka has number of man made lakes located close proximity to major cities. Beira, Kandy, Kurunegala, Gregory are few of very famous lakes. These lakes bring aesthetic value to these cities and also act as tourist attractions. Kurunegala lake serves as the alternative water source for the domestic water supply system in the area. However, most of these lakes are not protected from pollution hence, have subjected to severe degradation. Fish kills and bad odour have been reported in all these lakes as a result of poor water quality. Successive governments have spent millions of money for dredging of sediments and sludge in order to restore the lake environments. However, these measures will be temporary solutions unless otherwise strict measures are taken to control pollution sources in the catchment area through proper management interventions.

2. LAKE GREGORY AND ITS CATCHMENT Lake Gregory is located very close proximity to the centre of the Nuwara Eliya town and is a major tourist attraction. It is a manmade lake constructed by Sir William Gregory (1872-1877). Surrounding area of the lake is dominated by major habitats such as fresh water marshes, streams, degraded montane forest and agricultural lands (IWMI, 2006). At the time of construction of lake Gregory, the total water area was reported as about 91.2 hectare and it has decreased with time due to several reasons including sedimentation (UDA, 1996). The catchment of Lake Gregory mainly consists of semi – urban and agricultural land uses. The tea plantations inside the catchment are located in the areas of Nesby and Pedro estates. The main cultivation area within the municipal council area is Moon Plains, having an area of 34 hectares (UDA, 2004) and also partly inside the catchment of the lake. Half of the municipal council area of Nuwara Eliya town is located inside the catchment of Lake Gregory. It is a well known fact that lake Gregory is polluted due to several reasons including discharge of human and domestic waste and chemicals from agricultural lands. The fertile sediments which are resulted by soil erosion and transported from the tributaries of the Gregory Lake via agricultural fields 154

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encourage the aquatic plant growth (UDA, 2004). The catchment of Gregory Lake has intensive vegetable cultivation and high population density and therefore high amount of urban wastewater and sediments come through runoff (Amarathunga et al., 2010). Water quality data of Lake Gregory shows the presence of the nitrogenous and phosphorus compounds, iron etc. (UDA, 1996). To maintain the aesthetic beauty of the lake, it is important to maintain the quality of water. In this respect, identification of the threats faced by the catchment area due to agricultural and other human activities is a prime importance. Within this background, the objective of the study is to assess the agricultural activities taking place within the Gregory lake catchment and surrounding agricultural areas to identify their impact on the soil and water pollution.

3. MATERIALS AND METHODS The primary and secondary data used in the study are listed in Table 1.

Table 1: Data used in the study

Data Source/ method of collection Primary data (Information on agricultural Questionnaire survey practices and water quality issues) Secondary data Topographic maps Survey Department of Sri Satellite Images: Lanka LISS III (1998, February) Internet sources LISS II (1992, March) Landsat TM (1992) The questionnaire survey was not only limited to the catchment area of lake Gregory. To get an overview of the agricultural activities on environment and socio-economic condition of the people, the survey was conducted using 50 household units located within fifteen Grama Niladhari divisions in close proximity to Nuwara Eliya. Following information was collected using the questionnaire survey. - Characteristics of the farm plots - Characteristics of fertilizer and agrochemical applications - Availability of drinking water and nature of the water sources - Possible socio-economic and health impacts of water pollution Environment related data were collected by a field survey within the catchment of lake Gregory in 2008. The possible pollution sources, nature of

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land preparation, fertilizer application, possible impacts of these activities on water resources, inflows to the lake Gregory, nature of the surrounding of Lake Gregory and growth of aquatic plants were observed during the field visits. The satellite images of Nuwara Eliya; LISS III (1998), LISS II (1992) and Landsat TM (1992) were used primarily to identify the general land use in the catchment and the temporal changes. Topographic maps of 1:63360 and 1:50000 scales were also used. Remote sensing (ERDAS Imagine), GIS (Arc GIS) and Microsoft Excel software were used for the image analysis and interpretation of spatial and survey data. Supervised classification technique was applied to multi temporal satellite images to obtain land use condition of the Lake Gregory’s catchment. Subsequently, change detection was carried out. The areas of the water surface in Gregory Lake were calculated using images of LISS II (1992), LISS III (1998) and topographic map (1976) to assess the temporal changes in lake area.

4. RESULTS AND DISCUSSION

4.1 Education status and environmental awareness of people

Fifty six percent of the sample has obtained secondary education. Thus, they should have the knowledge of agricultural pollution and its general impacts to the environment. However, De Silva, (2009) has revealed that the educational standards and literacy level of the estate population in Nuwara Eliya district is far below the national level. Thirty percent of the members (both males and females) of the sample are engaged in farming as their primary occupation. Except this portion, about 19% of sample population is engaged in farming as their secondary occupation. This shows the high involvement of people in agricultural activities in Nuwara Eliya, providing evidence for environmental degradation. The rest of the sample is involved in the labour works (7%) including estate labour. There is a big diversity in land ownership in the study area. According to the survey, 57% of the sample owns their lands while 9% is under encroached land. These lands have been encroached from the reservation areas making streams and other important land features vulnerable to pollution and degradation. With respect to soil conservation, majority (61%) of the lands are in poor state with no soil conservation measures. The farmers in those households cultivate their lands even in steep slopes without considering the possibility of soil erosion. According to the field observations, it is evident that these lands are totally bare just prior to start cultivation and highly vulnerable to soil erosion. About 22% of the households were engaged in intensive farming activities. They have used every space in the land for cultivation. The edges and the banks of the water bodies, drains and streams are cultivated by the farmers creating a huge threat to the water sources. Virtually, there are no riparian areas left in small streams running in these areas. There is a great possibility to 156

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contaminate the water sources by the fertilizers and pesticide applications to the cultivations at banks of such water bodies. The Majority of the farmers (50%) do not apply soil conservation methods even though they have their own lands. The main reason for this can be lack of awareness about soil conservation, carelessness about the economic capability of the land (focus group discussions with farmers, 2008). Out of total sample, about 36% of farmers have applied soil conservation methods whether they are owners or not owners of these lands. 4.2 Fertilizer and agro-chemical usage in the area The fertilizers applied by the farmers in the surveyed area are many times higher than the recommended standard application rate of Department of Agriculture of Sri Lanka. The over applied amount as a percentage of standard amount for the given fertilizers for the given crops are given in the Figure 1. According to Mubarak (2000) Sri Lanka is the highest fertilizer consumption (101.5kg/ha) country in the SAARC region and it reflects the excessive and inefficient use of fertilizers by the farmers.

Figure 1: Percentage differences between average application rates and recommended standards of Department of Agriculture (DOA) for selected fertilizers According to the information provided by the farmers during the survey, the average application rates of MOP (Muriate of Pottash) is 495%, 606%, 1588% and 217% higher than the standard application rate of MOP by the Department of Agriculture for the crops of potato, carrot, beet and leeks respectively in the study area. Beet crop has the highest over applicatio n percentage as 1588. The average application rates of TSP (Triple Super Phosphate) is 12% and 530% higher than the standard application rate of TSP by the Department of Agriculture for the crops of potato and carrot respectively. The average application rates of Urea is 55%, 136% and 308% higher than the standard

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application rate of Urea by the Department of Agriculture for the crops of Carrot, Cabbage and Leeks respectively. The average application rate of Urea for Beet is 84% which is less than the recommended rate of the Department of Agriculture. Excess application of fertilizers will lead to accumulation of nutrients in the soil profile and also leaching and washing off with rainwater.

Since farmers are over applying the fertilizers than the standard recommended rate given by the Department of Agriculture, there is a great possibility to retain the excess fertilizers in the soil profile. The build up of phosphorus in the cultivated soils is a result of adding much more phosphorus in the form of fertilizer than is removed by the harvested crop. Taking carrot as an example, the survey showed that on an average the farmers apply 680 kg of triple superphosphate per acre. This amounts to the addition of 293 kg of phosphorus to a hectare. However, a 40 tonne carrot crop (fresh weight) removes only about 15 kg of phosphorus from one hectare of land(Potash Development Association, 2010). This calculation shows that every time a carrot crop is harvested, the soil gains a quantity of 278 kg of phosphorus, assuming that none of it leaves the field. If this practice of adding excessive amounts of P fertilizer for two to three crops a year continues, the soil P levels will build up to very high levels, some of the high P soils will enter water bodies as runoff, P content of the water will rise sharply, and pave the way for algal blooms to become common occurrences in the water bodies like Gregory lake. According to the soil test based recommendations given by Department of Agriculture (1995) the Olsen phosphorus in soil of 30 ppm is generally considered adequate. In Nuwara Eliya district 65% of intensively cultivated lands have higher soil phosphorus than 30 ppm and 30% of the lands have phosphorus in soil higher than 120 ppm (Yapa, 2010). The Olsen phosphorus content in some cultivated soils of up country is as high as 400 ppm (Wijewardena, 2011).

The use of pesticides in the study area is given in Figure 2. According to the information, fungicides are widely used by the farmers in vegetable cultivations in the area. The survey revealed that all these pesticides are overused compared to the recommended application rates.

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Figure 2: Pesticides used by the farmers in vegetable farming in the study area.

4.3 Agriculture and other human activities in Catchment o f Lake Gregory

Other than the forest area in the upstream, rest of the catchment of lake Gregory is occupied with either agriculture or built up lands including a part of Nuwara Eliya municipal area. Hence, major water pollutants of the lake are of agricultural or urban origin. Major agricultural activities in the area are vegetable cultivations and tea plantations. The major vegetables crops cultivated in the catchment area are cabbage, beet, carrot, leeks and potato. Questionnaire survey identified that similar pract ices are carried out by the farmers in the lake catchment as other farmers in Nuwara Eliya. Number of small tributaries flow into the lake from agricultural areas carrying sediments and agricultural pollutants. According to the key informant interviews, f armers used to wash vegetables and sprayers by dipping in some of these tributaries. The accumulation of floating aquatic plants at the edge of the lake is common. According to the key informant interviews, wastewater from the hotels located in the surroun ding is also contributing to the pollution of lake water. 4.4 Land use changes in the catchment of Lake Gregory The changes of land use of catchment of Gregory Lake in 1992 and 1998 were investigated by using satellite images. According to the land use maps prepared using Landsat TM image of 1992 and IRS LISS III (1998), general land uses were identified as cultiva ted, non cultivated and water. The areas under each category was calculated and illustrated in the Table 2.

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Table 2: Land use pattern in Catchment of Lake Gregory in 1992 and 1998.

Land use type Area (Hectare) -1992 Area (Hectare)-1998

Water 38.33 26.02

Non cultivation 947.77 893.60

Cultivation 660.59 727.08

The above statistics show that there is an increase in the cultivated area during the period. Sediments and agricultural pollutants are drained into the lake with the increasing agricultural activities. Reduction in the water surface area with time is an indication of either aquatic plant growth in the lake or high sedimentation. Water surface area of the Lake Gregory was extracted from the multi temporal satellite images and the changes in the surface areas were assessed to identify the morphological changes with time (Table 3). This is an indication of the changes in the physical condition of the lake due to sedimentation and aquatic plant growth.

Table 3: Water surface areas of Gregory Lake

Image Year Area (hectare)

Topographic map 1976 45.54

IRS LISS II 1992 (March) 45.62

IRS LISS III 1998 (February) 30.34

Accordingly, the water surface area of Gregory Lake in 1998 has reduced compared to the water surface area in 1992. The details of Urban Development Authority revealed that there was a huge occurrence of algal bloom and aquatic plant growth on the water surface of Gregory Lake in 1998. This can be a major reason for the deduction of the water surface area. The Urban Development Authority has carried out dredging by spending huge cost to clean the lake Gregory.

5. CONCLUSIONS AND RECOMMENDATION Over application of fertilizers and pesticides has become a common phenomenon among farmers in Nuwara Eliya area to gain maximum economic benefits from their farmlands. However, the environmental and socio-economic cost of these activities is evident through soil and water pollution and high 160

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amount of money spend on restoration of lake Gregory. Land use dynamics in the study area is evident through the land use changes of lake Gregory catchment. Conversion of more lands to agriculture will bring more burdens to the environment since these lands are used for intensive agricultural activities with heavy usage of agro-chemicals.

It is important to investigate the reasons for the farmers to apply overdoses of pesticides and fertilizers since the findings of this study are based on a single questionnaire survey. As a long term measure to control soil and water degradation, awareness programmes should be conducted to the farmers to educate them on the impacts of over use of fertilizer and other agro-chemicals and on the importance of applying soil conservation methods in their croplands. In addition, public also should be made aware of possible health and socio- economic impacts due to consumption of poor quality water. A programme should be implemented for strengthening the extension services in intensive agricultural areas of Nuwara Eliya. Environmental conservation of the catchment of Lake Gregory can be introduced with the support of government and non-government organizations. A lake management committee can be formulated with the participation of all relevant stakeholders since it is important to maintain the quality of the lake environment due to high economic value of the lake as it is a major tourist attraction.

6. REFERENCES Amarathunga, A.A.D., Weerasekara K.A.W.S., Sureshkumar N., Shirantha R.R.A.R. and S.A.M. Azmy 2010. Total Suspended Solis and Turbidity Correlation in Kotmale Sub- catchment of Mahaweli pcatchment, Water Resources Research in Sri Lanka, Symposium proceedings of The Water Professionals’ Day, Crossing Boundaries Project, Postgraduate Institute and Geo-Informatics Society of Sri Lanka, pp 115-124.

Amarasiri, S. 2007. Declining Water Quality and Its effect on Water Security, Water Resources Researches in Sri Lanka, Water Resources Research in Sri Lanka, Symposium proceedings of The Water Professionals’ Day, Geo- Informatics Society of Sri Lanka (GISSL), pp 1-10.

Amarawansha, E.A.G.S. and S.P. Indraratne, 2010. Degree of Phosphorus Saturation in Intensively Cultivated Soils in Sri Lanka, Short Communications, Tropical Agricultural Research, Volume 22 (1), pp 113-119.

Chandrasekara, S.S.K., Kumari, M.K.N., Aravinda, A.L., Galagedara, L.W. and N.D.K. Dayawansa, 2010. Effects of Delayed Cultivation on Irrigation Water Management and other cultivation practices: A case study in Maha – Illuppallama, Water Resources Research in Sri Lanka, Symposium proceedings of The Water

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Professionals’ Day, Crossing Boundaries Project, Postgraduate Institute and Geo- Informatics Society of Sri Lanka, pp 83-94.

Dayawansa, N.D.K. 2006. Water Pollution in Sri Lanka, Geo-Informatics Society of Sri Lanka.

Department of Census and Statistics. 2002. Sri Lanka, URL: http://www.statistics.gov.lk/agriculture/hcrops/index.html (Accessed on 2010/ 12/02)

De Silva, S. 2009. Water: A Root of poverty among estate women in Sri Lanka, Interfacing poverty, Livestock and Climate Change in Water Resources Development : Lessons in South Asia, Fourth South Asia Water Research Conference, Nepal Engineering College, Chargunaryan, Bhaktapur, Nepal, pp 78- 89.

Food and Agriculture Organization (FAO) 2011.Introduction to Agricultural Water pollution. URL:

Gunawardena E.R.N., Mahees, M.T.M., Gunawardene, I.P.P., Rathnapriya, E.A.K., Amarasekare, M.G.T.S. , S. and Thrikawala2010. Transdisciplinary Research in Integrated Water Resources Management in Addressing Issues Related to Water Pollution of Mahaweli River, Water Resources Research in Sri Lanka, Symposium proceedings of The Water Professionals’ Day, Crossing Boundaries Project, Postgraduate Institute and Geo-Informatics Society of Sri Lanka, pp 1-9.

International Water Management Institute (IWMI), 2006. Sri Lanka Wetlands Information and Database. URL: http://dw.iwmi.org/wetland_profile/Gregory.asp [Accessed on 2011/06/29]

Mubarak, A.M. 2000. Water Pollution, Natural Resources of Sri Lanka, National Science Foundation, Colombo, Sri Lanka.

United State Environmental Protection Agency (USEPA) 2009. Drinking Water Contaminants. URL: http://www.epa.gov/drink/contaminants [Accessed on 2011/05/03]

Urban Development Authority (UDA). 1996. Nuwara Eliya Environmental study; Environmental Action Plan, Volume 2, Roche International, Canada.

Urban Development Authority (UDA). 2004. Development Plan for Nuwara Eliya Urban Development Area (Nuwara Eliya Municipal Council area) 2004-2016, Volume 1, Situational Plan and Development Report.

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Wijewardena J.D.H .2011. Agriculture and Water Pollution in Sri Lanka, Water Resources Research in Sri Lanka, Symposium proceedings of The Water Professionals’ Day, Crossing Boundaries Project, Postgraduate Institute and Geo- Informatics Society of Sri Lanka, pp 3-17.

Wijewardena J.D.H. 1998. Impact of Intensive Vegetable Cultivation on Drinking Water Quality in the Upcountry Region of Sri Lanka, Status and Future Direction of Water Resources in Sri Lanka, Proceedings of the National Conference held at BMICH, Colombo, Sri Lanka.

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ASSESSMENT OF THE EFFECTS OF SURFACE WATER POLLUTION ON REDUCTION OF LAND VALUE USING GIS; A CASE STUDY OF THE HAMILTON CANAL IN WATTALA D.S. DIVISION

W.D.K.V. Nandasena 1, H.M.Paba Herath 1, S.I.S. Subasinghe 2 1Department of Social Sciences, Sabaragamuwa University, Sri Lanka 2Department of Geography, University of Peradeniya, Sri Lanka

ABSTRACT The Hamilton canal was built in 1821 by the British engineer Hamilton as an alternative water transport way to the Old Dutch canal. It drains from Puttalam to the metropolis of Colombo and flows parallel to the west coast of Sri Lanka. Water pollution in theHamilton canal has taken place due to various human activities. Contamination by undesirable objects thrown to the surface fresh water sources such as canals, rivers, and tributaries causes water pollution. There are many direct and indirect effects of surface water pollution on animals, humans, plants and ecosystems. Land value reduction is another effect that occurs as a result of surface water pollution. The main objective of this study wasto assess the effect of surface water pollution on reduction of land value using GIS analysis. This study also examined the socio- economic conditions of both urban and industrial areas that are subjected to water contamination. Water samples were collected randomly at nine places inside eight GN Divisions of Wattala DS Division inregular intervals. Initially pH,Electrical Conductivity, Total Dissolved Solids, Dissolved Oxygen, Salinity and Temperature were measured usinga water quality meter. Chemical Oxygen Demand was also determined. Secondly, information regarding socioeconomic and urban conditions related to water pollution and land values were collected using a questionnaire survey from randomly selected households in six GN Divisions in the study area. Finally, all the data were added into aGIS database and the relationship between water pollution and land value was shown on maps. SPSS and MINITAB software packages were used for statistical analysis. According to the study Balagala, Elakanda, Palliyawatta North, and Thimbirigasyaya was found high in water pollution. Study found high in pH value of 6.8 near solid waste reproduce centre and 28.5 ºC of higher temperature value near where the sub canals flows from Kerawalapitiya Industrial zone, to the Hamilton Canal in Balagala GN Division. Also it showed 0.6 Mg/l of high level of salinity too in the same GN Division. Study revealed, gradually increasing levels of Total Dissolved Solid in Palliyawatta North and Elakanda GN divisions with the amount of 1.6.Mg/l and 250 Mg/l higher level of COD due to the processes of rapid urbanization and the industrialization in Elakanda GN Division. Furthermore, high amount of 3.50 Mg/l of Dissolve Oxygen was found in Palliyawatta North GN Division. According to the survey, high land value of Rs1, 67895 to Rs2, 03200 (per perch) were manifest where less water pollution took places such as Palliyawatta South, Hekitta and Kurunduhena GN Divisions. And lower land value of Rs 97,000(per perch) was found in Dikowita GN Division where average level of water pollution occurred and moderate land value of Rs 97,001to Rs 167894 (per perch) was marked where GN Divisions found in highest water pollution in the study area.

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1.0 INTRODUCTION Water and the land are naturally occurring resources which assist to sustain the human life on earth.From the early times our ancestors built their civilization along the river banks, where the fertile land and the fresh water are available. At that time, demand of the land mainly based on accessibility to water sources and fertile soil. Nowadays this demand has changed with the availability of transportation, infrastructure and sanitation facilities etc. but still the water act as a key factor to determine the land value. However, quality of water will now play a decisive role in determining land value. Only 0.4 percent of the water available for the human being’s use is mainly divided into two categories as surface water and groundwater. Surface Water is the water that remains from Rain, Snow, Sleet, Hail, etc after evapotranspiration and infiltration losses. These waters are stored in streams, rivers, lakes, tanks, and canals. Ninety-five percent of all fresh water on earth is groundwater. Ground water is found in natural rock formations. These formations, called aquifers, are a vital natural resource with many uses . Water pollution occurs when a body of water is adversely affected due to the addition of large amounts of unnecessary materials to the water. Water pollution can be defined as “contamination of water by undesirable foreign matter” (http://www.cotf.edu/ete/modules/waterq/forms.html). Today the water quality of many canals in the world is severely deteriorated, placing a risk at the health and livelihoods of all those who reside along their banks. Every year, 19 trillion gallons of waste enter the surface water. Pollution of freshwater is a problem for about half of the world's population. Each year there are about 250 million cases of water-related diseases reported with roughly around 5 to 10 million deaths. Among the key environmental issues of the South Asia, freshwater pollution and scarcity have became most prominent issues of the region. Limited access to potable water, water-borne diseases, arsenic contamination of drinking water, seasonal limitations of availability of natural freshwater resources, depletion of freshwater aquifers, organic pollution and specially the degradation of land resources due to surface pollution are some of the matters include in this issue. Pollution of Sri Lanka’s water occurs throughout the island from domestic, industrial and agricultural sources. Contamination of wells from urban discharges and agrochemicals are rising in rural and urban areas. 1.1 Study area Hamilton canal drains from Puttalam to metropolis of Colombo and flows parallel to west coast of Sri Lanka. It flows within W4 agro ecological region in low country wet zone where rainfall is over 1525mm/annum and with a flat terrain. Soils are bog and half bog and are highly acidic. Tide alone causes oscillating flows in the canal with discharges of 1.5-4.5m3/s and velocities of 0.1-0.25m/s. Salt penetrates into Hamilton canal during dry season. 166

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According to the land utilization pattern, nearly 55% of the land is homestead. This situation has lead the area to become semi urban, hence paddy and marshes have been filled for construction purposes. When look in to the historical perspectives, this 72 mile long, 16m-18m wide, 1.5m-1.75m deep(at the center) canal was built by British in early 19th century for the purpose of transporting cinnamon those collected from hinterland of Negombo and other areas. At present, the area is facing several issues such as industrialization, urbanization, improper garbage disposal and flood hazard. Thus water pollution is prominent and potential of spreading diseases, ground water contamination, flash floods are common and reduction in land value close to the canal is evident compared to other canals that flow along the wattala D.S division. Researcher made a hypothesis that there is a direct relationship between surface water pollution and land value reduction in the selected area. This study considered a part of the Hamilton canal which belongs to Wattala D.S. division including the GN divisions of Palliyawatta North, Palliyawatta South, Tibirigasyaya, Elakanda, Uswetakeiyawa, Pattiyawala, Dikowita and Balagala as the study area. Total size of the study area was 6 square kilometers. 1.2. Materials and Methods Primary data for the study were obtained both from fieldsurvey and water sample collection . Secondary data such as maps of the study area and details of the water pollution status were collected mainly from government institutions. Field survey a). Questionnaires Sample size of the questionnaire was 45 households (166 population) that selected randomly. Survey was conducted in residence households which are located along the canal. Houses in 6 GN divisions were covered by the survey and some GNs were weighted in the questionnaires according to the observed pollution sources. b). Observations Observation method was used for selecting the location for the hypothesis testing and for the water testing methods. In the field, observation method was used for identifying the pollution sources, interaction of residents with the Hamilton canal.

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Water Testing Techniques

Water testing techniques used to measure the pollution states of the canal varied according to the GN divisions in order to facilitate the hypothesis. a). Water sample collection

9 locations were selected to measure 10 parameters. These 9 locations were selected randomly in regular intervals and within a single period of time, according to the location specifications. These points were scattered around the mouth of canal to the 4km post of B 469 road (Figure 1). 6 parameters were measured in each point while samples of COD measured only at four selected sample locations. In addition, fecal coliform was measured at the residential area (point 6). b). Determination of pH, EC, TDS, DO, Salinity, Temperature, FC, TC and COD inwater Water quality meter was used to measure the water samples at in-situ conditions. pH, Electrical Conductivity, TDS, DO, Salinity and Temperature were checked. FC, TC and COD were tested in the laboratory.

Figure 01: Locations where the water samples were collected

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Collected Quantitative and qualitative data were analyzed by using various software packages. ARC GIS 9.2 was used to develop the maps of study area, land use, buffer zones for flood, land value and pollution status. SPSS software package was used for the analysis of data acquired through the questionnaire. Chi square, correlations and hypothesis tests were performed as statistical analysis. MINITAB 14 was used to check the model fitness and regression line. Excel package was used to analyze the water testing results. Qualitative data was used to support the results obtained from other methods.

2.0 RESULTS AND DISCUSSION

2.1 Socio-Economic condition of the study area Hamilton canal is draining through Muthurajawela wetland, residential areas and through the industrial zone. Muthurajawela marsh area is gradually shrinking as a result of encroachments. Coconut, rubber and paddy are gradually diminishing and rubber cultivations have totally extinct from the study area. At present, paddy lands have become very less (Figure 02) and there is no commercial fishing in the canal area. Hamilton canal is used as a harbor close to Dikowita.

Figure 02: Land Use Pattern of the Study Area 169

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At a glance, the study area represents the characteristics of a fishing village while people of the area were multiethnic and multi religious. A total number of 166 people live in the 45 households involved in the questionnaire survey and majority of them was Sinhalese Roman Catholic representing fishing society characteristics of Sri Lanka. Middle class emerged as the majority of the study area with average monthly income ranging between Rs. 25,000 - 30,000. Table 01 presents the information of the fishing population in the study area.

Table-01: Basic information of the fishing population in the project area FI Fishing Fishing Fishing Population division village households families Wattala Palliyawatta 105 140 700 south Palliyawatta 60 80 400 north Dckowita 190 240 1200 Balagala 40 50 250 Source –CEA, 2007 The age category of 1-20 was found as the highest which is the child population. Thirty two percent (32%) of the population was in the category of 21-40 years which represent the key labour force. In addition, 23% represent consists of the middle age population and only 10% represent the old people. Thus, economically active population is very much higher in the study area. Fishing was the main livelihood. It represents 41% of the whole self- employments. In additions for fishing, people were engaged in many other businesses. A considerable portion (18%) of the people in the study area are only educated up to grade 10. The main domestic water source is the water supplied by the National Water Supply and Drainage Board with 98% of the surveyed population has the connections. This water is used for drinking, bathing and washing purposes. Main reason for not using the natural water sources was the contamination of water sources. The fraction of Fecal coliform present in the water was high (0.9000) indicating poor hygienic conditions. High COD (153.9 mg/l) shows the contamination of water with industrial effluent. High turbidity level (30.2 NTUs) indicates high level of suspended material present in water. Thus none of the residents use shallow or deep groundwater (tube wells) for their daily needs. Instability of soils which consist of peat bog soils and sands is also another reason for not constructing wells since these soils are unstable for digging. These soils further help canal water seepage into deep soil layers. Many wells are contaminated with salts since location is close to the sea. In addition, high land fragmentation is also another reason for not having individual wells due to limited space.

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Declining land value Heavy fragmentation of land is a key feature in the study area. This is severe in the urban areas compared to the rural areas. The correlation analysis between the selling price of a unit of land and the size of the individual allotments show a moderate correlation with R value 0.52 at p =0.050. In Palliyawatta North GN division, a considerable portion of people (44%) live in land plots less than 10 perch each. In Elakanda area, all fragmented lands are distributed equally along the area. About 27% of the people live in land portions ranging from 11-20 purchases, and only 11% persons live in more than 40 perche land in the study area. The study revealed, water pollution, floods and diseases, as major facts behind the land value reduction in close proximity to the canal. According to the field observations and questionnaire survey, garbage disposal, waste water discharge, industries are the main water pollution sources. 45% of the people from the study area used to burn their garbage, and 32% were maintaining their own garbage pit in their houses, 14% people give their trash to town council garbage tractor and 7% put their waste into a public place which town council used to dispose their garbage. According to the survey, only 2% of them used to discharge their waste in to the canal. However, according to the water quality characteristics and high level of fecal coliform revealed that people discharge their wastes into the canal including toilet waste. According to the survey, 36% used to release wastewater straight to the canal and 34% used to release the wastewater to the drainage system that flows into the canal. Study area is a highly industrial area. Therefore, many industrial wastes were discharged freely to the canal. Though it is legally incorrect, field observations revealed that many industrial waste outlets are directed to the canal. High levels of COD were found in the Elakanda area due to the processes of rapid urbanization and the industrialization (Table 02, Figure 2). In addition, pollutants emit from the boats also responsible for water pollution. Cannel end was highly affected by industrial waste that drain from the kerawalapitiya industrial zone. Moreover, daily travelling of fishing boats also cause high COD levels in the Elakanda area. Table 02: COD levels of four points of Hamilton canal Points COD Level Point 01(Agro marine) 121.6 mg/l Point 02(Elakanda) 243.2mg/l Point 03 ( the sub canal 01) 114.0 mg/l Point 04 (End point) 136.8mg/l Source- Based on field survey

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Figure 2: COD levels in sampling points

In addition, the residents have observed dumping of waste such as chicken wastes from farms, bodies of dead pets etc. due to lack of land. Identifying the pollution level of the study area and its variations among GN divisions is more effective in order to recognize the pollution sources. According to Figures 03 and 04 the pH value and salinity show a relationship with each other. High salinity and pH levels were found at point 7 (near solid waste reproduce center). This was mainly due to high percentage of waste by the abandoned solid waste recycling center.

Figure 3:pH value variations in the Hamilton canal 172

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Figure 4: salinity variations in the Hamilton canal Flood is the main problem faced by the households. Lands in between 1m - 20m distance from the canal were mostly affecting. This problem was worse in the illegally reclaimed areas especially in Dikowita and Balagala GN divisions. Location and topography of the area also e nhance the problem since study area is located in lowland (elevation less than 15m from msl), lower catchment of the Kelani river and due to peat and peat bog soil. Study found high pH value of 6.8 near solid waste reproduce centre and 28.5 ºC of higher t emperature value near where the sub canals flows from Kerawalapitiya Industrial zone, to the Hamilton Canal in Balagala GN Division. Also it showed 0.6 mg/l of high level of salinity too in the same GN Division. Study revealed, gradually increasing levels of Total Dissolved Solid in Palliyawatta North and Elakanda GN divisions with the amount of 1.6.mg/l and 250 mg/l higher level of COD due to the processes of rapid urbanization and the industrialization in Elakanda GN Division. Furthermore, 3.50 mg/l of Dissolve Oxygen was found in Palliyawatta North GN Division. According to the survey, high land value of Rs1, 67895 to Rs2, 03200 (per perch) were manifest where less water pollution took places such as Palliyawatta South, Hekitta and Kurunduhena GN Division s. Lower land value of Rs 97,000(per perch) was found in Dikowita GN Division where average level of water pollution occurred and moderate land value of Rs 97,001to Rs 167894 (per perch) was marked where GN Divisions which reported highest water pollution in the study area.

3.0 CONCLUSIONS AND RECOMMENDATIONS The Hamilton canal is polluted due to household and industrial discharges as it is running through an area which is highly urbanized and industrialized. The study revealed that the study area is highly congested due to land

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fragmentation and the residents mainly depend on piped borne water supply. The shallow groundwater is polluted due to seepage of canal water in peat and peat bog soil. High Fecal coliform levels in water indicate sewage pollution. High COD in canal water also an indication of industrial pollution. According to the study, high land value was found where less water pollution is occurred. Moderate land value was identified in the area where high water pollution occurred. Less land value was identified where moderate water pollution occurred and away from theurban area . Flood hazard and socio cultural condition further enhanced the situation in the area. Land value reduction and the surface water pollution were the major problems of the area while flood hazard further worsen the stage. To overcome the land value reduction, it is important to control water pollution in the Hamilton canal. Hence, the industrial discharges should be strictly controlled and prior treatments are necessary before discharging. Water purification can implement in the sub canal mouths by using bricks and gneiss. A strict legal procedure in necessary to control discharge of toilet waste into the canal hence it should make it mandatory to obtain prior approval for construction of houses. Illegal constructions in the environmental sensitive area have to be removed without any political influences. To overcome the flood hazard, bank protection should be done and illegal reclamations should be stopped. Since this canal is located in an area with scenic beauty, tourism can be promoted. It will help to increase the land value. Water transportation system can be introduced in Hamilton canal and the riders can travel between Negombo-Colombo. This will directly benefit the people of the study area by generating occupations and high demand for fishing. This also indirectly enhances the attitudes of the residents toward maintaining a clean environment. This will help to increase the land value.

4.0 REFERENCES Changhua.W.A., Maurer.C., Xue.S., and D.L.Davis. 1999. Water Pollution and Human Health in China."Environmental Health Perspectives Volume 107. Dayawansa, N.D.K.& Ranjith Premalal W.P. 1998. Modelling Non-Point Source Pollution Risk at Nilambe Catchment, SLASS Annual Publication,Colombo. Michel. H.J. 1996.Water Quality Affects Property Price, Marine agriculture and forest experiment Station, University of Maine. Rana, S.V.S. 2005. Essential Ecology and Environment Science, Prentice Hall of India, Delhi Pielou, E.C. 1998. Fresh Water. Chicago and London: The University of Chicago Press.

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http://www.enchantedlearning.com/geography/continents/Land.shtml (Accessed on 09.15.2010). http://www.fao.org/docrep/w2598e/w2598e04.htm.(Accessed on 06.06.2010). http://www.fao.org/docrep/w2598e/w2598e04.htm (Accessed on 09 05, 2010). http://www.henrygeorge.org. http://www.henrygeorge.org/ted.htm (Accessed on 09.14, 2010). http://www.pollutionissues.com/Ve-Z/Water-Pollution-Freshwater.html (Accessed on.07 23.2010). http://en.wikipedia.org/wiki/PH. (Accessed on 10.04.2010). http://en.wikipedia.org/wiki/Salinity. (Accessed on 10.04.2010).

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