Problems and prospects of utilizing canal banks to enhance the built-environment in Colombo

Waterfronts are assets that enhance the quality of built-environment in urban areas. They are used as public and recreational spaces in many cities around the world. However, cities and towns in Sri Lanka most often turn their back to water bodies. Colombo has environmental assets in the form of a sea front, a lake and a canal network, yet not much attempt has been made to utilize their potential to enhance the quality of environment of the city until recent times. The lake is being rehabilitated while the canal network has already been rehabilitated under externally funded projects. It is observed that the rehabilitated canal network is fast falling back to its previous state of stagnation and pollution due to non-utilization of improved canals and banks. This paper focuses attention on possible strategies to sustain their improved environmental quality in order to enhance the built-environment of the city.


Introduction
Cities located along rivers and canals is a spatial phenomenon in many countries in the world. However, virtually living on these water bodies themselves is a specific phenomenon seen in Southeast Asian cities. For example 23% of houses in Ho Chi Minh City's canal bank settlements are completely located over the canals' water surface while 62% of houses are partly located on land and partly located on canals. In the canal bank settlements of Bangkok, the figures are lower at 15% and 47% respectively due to the frequent use of canals for transportation purposes (Dong, 2002:54). Although waterways are not used for settlements to that extent in South Asian countries, this region also demonstrate an urban development pattern highly associated with rivers and canals. Most cities and towns in South Asia are founded in association with sea, rivers and other water bodies.
Water-based settlements date back to the earliest periods of civilization in the Asian region. People settled along water bodies not only for the ease of obtaining water for agricultural purposes but also for the ease of movement. Rivers and canals have often served as major lifelines to these settlements for the purposes of obtaining food, consumer goods and service necessary for their sustenance. As a response to this significance the buildings located along the banks usually faced the water bodies. However, with the rapid progress in land transport technologies the importance of waterways as arteries of settlements has gradually diminished. Roads have taken over the function of water bodies as the primary means of getting access to buildings and serving transport needs. With these new developments waterways have been neglected and became backyards of buildings. Additionally, they have become dumping grounds for solid and liquid waste disposed from numerous industries, commercial establishments and houses located along them. More over, with rapid urbanization, banks of water bodies have become popular squatting grounds for migrants who could not find better footholds in cities. They have conveniently encroached river and canal reservations for settlement since these are public properties in most instances. These encroachments as well as dumping of wastes by households, industries and other establishments have caused poor environmental conditions in many water bodies over the period of time.
After having had a long period of similar fate, Colombo's canals have at last acquired a new look by undergoing "an expensive facelift". The silted, polluted and stagnating pools of water of yesteryear are no more. The shanties that crowded the banks, making the canals an eyesore are no longer there. What prevails now are wide expanses of water that actually flow, neatly constructed banks and upgraded houses lining the canal reservations. However, there are signs that after having a new life for a short period the canals are gradually falling back to dis-use due to insufficient maintenance, monitoring, pollution and utilization. Unless strategies are identified to sustain the improved quality of canal environment, the colossal amount of funds spent on rehabilitating Colombo's canal system will be wasted. This paper focuses on the strategies of sustaining the environmental quality of long abused and recently rehabilitated canals in Colombo, as urban waterfronts to enhance the built-environment of the city.

Need for Canal Rehabilitation and Maintenance
The commonest environmental problem in a canal eco system is the deterioration of water quality due to the presence of faecal matter, toxic substances, garbage and other organisms. This is associated with foul smells and unpleasant appearance of dark and murky water. Thesey easily become breeding grounds for disease carrying parasites and rodents. As a result public health of those who live close to canals and use water therein are threatened by water borne diseases. Dumping of solid waste and encroachment by shanties result silting and narrowing of canals. The combined effect of these disturbances is poor drainage capacity of canals and recurrent floods during the rainy season.
The socio-economic as well as environmental hazards posed by polluted, silted and encroached canals necessitate rehabilitation of them to safeguard cities and their people from calamities. Especially, periodic rehabilitation of canals is a major flood control measure in most water-based cities since it is very vital to maintain the capacity and flow of canals in order to protect cities against flood hazards.
However, in most cities in developing countries canal rehabilitation and maintenance are tedious tasks since canal banks are encroached by people for various activities including settlement. Therefore, canal rehabilitation projects often include strategies to rehabilitate and improve the quality of environment in canal bank settlements if encroachers are not completely evicted and relocated. In addition to the usual rehabilitation strategies such as dredging of canals, clearing of reservations and consolidation of banks, the housing condition of people living along the banks are also improved in order to prevent them from encroaching and polluting the canals again. Special measures are taken to prevent domestic wastewater, sewage and solid waste from entering the canals. Accordingly canal bank rehabilitation is a complex type of project involving civil engineering, environmental management, social development, and urban design strategies. However, if the improved qualities of settlements as well as canals are not sustained in the long run implementation of such strategies may be futile exercises. Therefore, it is very vital that the improved quality of built environment in settlements and condition of canals are sustained in order to reduce the vulnerability of cities to floods and other environmental calamities.
This paper examines the above need with reference to the Greater Colombo Flood Control and Environment Improvement Project, which was implemented in 1990s. It argues a case for the need of sustaining the environmental quality of rehabilitated canals through nonconventional methods of maintenance.

Greater Colombo Canal System
The City of Colombo is located in the flood plain of Kelani River. Most of the land presently occupied by the city had been marshy land reclaimed for urban development over a period of nearly 500 years. Presently there is an extensive canal cum lake system, which drains storm water to the river as well as to the ocean (see fig.1). This system is partly natural and partly man-made. The Dutch who occupied Colombo in the 17 th & 18 th Century have improved this system to use it for inland transport purposes and to protect the city from floods. There had been an extensive inland water transport system running from North to South, cutting across the major town centers located on the western coast of Sri Lanka. Thus, the canals have formed a continuous link of waterways between sea or river ports and the remote sections of territory under the Dutch. There had been settlements along Dutch built canals as still seen in some parts of the northern suburbs of Colombo. However, houses built on stilts over the water surface of canals as seen in Southeast Asian cities are not common in Sri Lanka. narrower and shallower. This has reduced the capacity of canal system to handle storm water during a flood event.

Flooding in Colombo
Before the implementation of the Greater Colombo Flood Control and Environment Improvement Project, many parts of Colombo City were subject to frequent flooding due to insufficient capacity of the canal system. The canals were partly undersized, badly silted and not maintained to the necessary extent. On the other hand marshy land have been reclaimed and developed most often in an unplanned manner without due regard to local and general drainage patterns. These unplanned reclamations have reduced the flood storage capacity within the wetland system as well as the canal system. Frequent flooding of many parts of the city has been adversely affecting the economic activities and public health. UDA identifies that "without prejudice to other serious problems, flooding is the most critical environmental problem in the city, directly affecting almost every other environmental and development issue" (UDA, 1998:81). After experiencing the heaviest rainfall of 495 mm/24 hr. and a devastating flood that followed on June 4, 1992, which paralyzed the city and its suburbs for a week, the authorities strongly felt that a complete rehabilitation of the canal system as an urgent need. The initial investigations have revealed that the canal system is not only undersized but also heavily polluted due to discharging of wastewater, sewage and garbage by canal bank dwellers as well as industries. Although squatters were identified as the cause for undersizing, some industries were identified as the main culprits of water pollution. In order to address the dual problem of flooding and environmental pollution, the Greater Colombo Flood Control and Environment Improvement Project was launched in 1993.

Greater Colombo Flood Control and Environment Improvement Project
The main objective of this project was to rehabilitate the existing canal system (43 km Sri Lanka Land Reclamation and Development Corporation (SLLRDC) was responsible for the implementation of this project, which was funded by the Overseas Economic Corporation Fund (OECF) of Japan. The OECF granted Rs. 4500 million (US $ 110 million) loan, which at that time was the largest provided by the Japanese Government for a single development project in Sri Lanka. Phase I of the project was completed in 1997 utilizing this fund and Phase II, which addresses the storm water drainage aspects of built-up areas is scheduled to becompleted in 2002.

Strategies to Sustain the Quality of Environment
A research study by Herath (1996)   Despite the initial show of interest, the reality is that not a single commercial activity has been established by the end of 2002. Among the activities proposed, most were restaurants of floating or stationary type. There were few proposals for boutiques, sports clubs and recreational activities. The breakdown of proposals is given below. The failure to generate sufficient enthusiasm among entrepreneurs and the general public can be attributed to the lack of a water-based entertainment culture in the city. Unlike Bangkok and Singapore where waterways are much celebrated spaces in urban life, people in Colombo show a lukewarm attitude to even larger waterbodies such as Beira Lake and Diyawanna Lake in the city. The former located in the heart of the city, is largely unnoticed since it is mostly shielded by warehouses and various other buildings. Although there had been several urban renewal proposals for the lake's surrounding, once again nothing has materialized yet, except a project to rehabilitate the lake.
Even before the emergence of security threats at public places people disregarded the Beira Lake due to its unpleasant environmental conditions. In contrast, the beaches in Colombo always attract crowds seeking leisure spaces. Therefore, a well-organized promotion campaign is needed to attract people to canal banks and make commercial activities successful. Without that the authorities will not be able to generate sufficient funds for maintaining the canals. A World Bank sponsored canal rehabilitation project in Ho Chi Mmh City (Saigon) has demonstrated that improved environmental qualities can be sustained by promoting commercial, recreational and public activities along canal banks despite poor quality of water in the canals (see Fig.5). However, a research study conducted by Bandaranayake (2000) on the viability of utilizing Colombo's canal system indicate that weak integration of canals with the rest of the urban fabric as a major draw back in introducing sustainable activities along canal banks. Transport activities will be useful to aerate water in the canals and control the growth of Water Hyacinth. However, the above table shows that there is not much demand for investing in transport activities in the canals. Only a limited number of entrepreneurs wish to use the canals for leisure activities. Even i f there is interest such activities may not be possible without overcoming the following problems.
1. Depth of water in some canals is insufficient during the dry season for passenger boats. 2. There is insufficient headroom underneath some road bridges. 3. Tie beams of some bridge foundations do not allow boats to pass through when the water level is low.
4. There are no piers for passengers to embark and Too much garbage, especially plastic bags deposited on the canal beds interfere with boat engines.
5. There are not many origin and destination points of commuters along canals.
6. Unbearable smell of water at certain canal stretches may discourage people from traveling along the canals.
Due to these problems, Dharmapala et al. (1997) concludes that only leisure rides to experience the Heen Ela marsh, Kotte Lake and Diyawanna Lake will be feasible on a commercial basis, yet security concerns may not make it viable particularly in the Diyawanna Lake. Citing the success of nature trails and leisure boat rides operated by the Central Environmental Authority in a conserved wetland area north of Colombo (Dharmapala, et al., 1997) they view that boat rides along the loop consisting of Heen Ela, Kotte Ela, Kotte Lake and Kolonnawa Ela might be an attraction for both local and foreign tourists (see Fig. 1). Dharmapala et al. (1997) also views that commuter transportation may not be feasible due to the technical and environmental problems cited above. Significant saving of travel time would be achieved in the few routes they have studied if water level in the canals is satisfactory. Yet the study also expresses skepticism on social acceptance of boat as an alternative transport mode due to the poor quality of water, bad odour and security concerns. Boat as a public transport mode is very rare in Sri Lanka. Therefore, making it popular in a canal system, which is not so pleasant and not so conveniently located in relation to transport nodal points, is not a very feasible idea.
Despite this non-feasibility Dharmapala et al. (1997) finds that leisure riding and recreational sports such as rowing may be practical in some canals. the quality of water and canal environment, other stakeholders need to partner with SLLRDC to ut the improved environments into public uses so as to ensure that they will not become backyards again.
The importance of civic mindedness and co-operation of the public is stressed in this regard. Much money has been spent on expanding and rehabilitating the canals. If the public continues to either encroach or use them as garbage dumping grounds, no purpose will be served. More over, local politicians should not encourage encroachers for selfish reasons. The authorities find it difficult to take actions against offenders when they have political patronage. Since selfmaintaining activities are not so viable along the canals, a concerted effort by the public as well as those in authorities is needed to ensure that the canals are kept unobstructed and clean in order to enhance the quality of environment in the city.