A half a day session was conducted on “Urban Lakes - Problems, Challenges and Solutions” by Mr. B. V. Subba Rao at Maheshwari Complex on Saturday, April 21, 2012. Mr. Rao is one of the founder members of Save Our Urban Lakes (SOUL) and the current president of Centre for Resource Education. He works extensively on saving and protection of lakes.
After the introduction of the participants, the presentation started with an insight into the coverage area of urban lakes in Hyderabad in the year 1920. For a comprehensive understanding of the urban lakes, Mr. Rao delved into technical definitions of concepts like Watershed, Catchment Zone, Lake Basin, etc. He also dealt with the aspects of lake like Foreshore, Full Tank Level (FTL), Littoral zone, Dead Storage, Bund, etc that drew a complete picture of what a lake comprises.
Impact of Urbanization:
Mr. Rao gave a detailed account of how the process of urbanization has affected the sustenance of lakes. He highlighted the fact that Urbanisation not only disturbs the natural watersheds but also induces dynamic changes in local hydrological regime and that Urbanization has direct bearing on lakes / water bodies. There was a focus on the fact that induced changes like increased rain /storm water runoff, localized urban flash floods, inundations, rapid siltation of lakes, loss of rain water retention capacity in lakes, generation of surplus flood waters, depleting ground water levels had a tremendous effect on urban lakes. The factors inducing the change were identified to be
- Lack of knowledge and understanding urban watersheds & hydrology
- Increased build up areas – pavements, parking areas, concrete structures.
- Lack of grass padded zones
- Loss of open green spaces.
- Inadequate tree cover.
- Encroachments on natural nalas / streams and lake bed areas.
- Violation of urban zoning regulations
- Highly disturbed natural watersheds
The drastic difference between the pre-urban and post-urban conditions of water infiltration, retention and evaporation were graphically shown. Mr Rao was of the opinion that the urban lakes were threatened by certain factors like physical encroachments on foreshore and lake bed areas. Land near the lake foreshore attracts real estate business for its scenic value; leading direct discharge of untreated municipal and industrial waste waters. This results in loss of rain water storage capacity and water quality.
Several interesting photographs were a part of the presentation and they gave the audience a clear picture on lake encroachment and also highlighted the diabolic state of lakes. A fundamental question was raised about how the degradation of the quality and quantity of lakes is a part of sustainable urban development.
By using the digital elevation model, Mr. Rao threw light on the fact that industrial effluents led to the contamination of lakes. He further talked about the fact that housing colonies are being constructed in dried lakes. According to the govt rules, if the lakes do not receive water for three consecutive years and the lake remains dry, then the lake area comes under the jurisdiction of the Revenue Department. Here, Mr. Rao alleges that is this process is a flaw as one cannot come to conclusions about the natural water cycle. An example was cited showing the flooding of houses in Rajiv Nagar which were constructed in Maisamma Tank.
There was also an emphasis on the social dimension of the lakes. In the earlier days, the lake with clean water was a source of livelihood for the dhobis. However, the dhobis are deprived of livelihoods because of policy issues and due to the deterioration of the water quality in the lakes.
Mr. Rao is of the view that lake protection and restoration should be a part of urban planning. Unregulated & unplanned urban development would contribute to severe consequences like:
- Environmental degradation
- Alters local weather conditions
- Induces changes in local hydrology
- Also, contributes towards Global Climate Change.
He is of the impression that climate change is a two way process which induces changes in hydrological cycle and also has an impact on rain fall pattern. Therefore, there is a reduction in the number of rainy days. The rainfall is of short duration with high intensity. In consequence to this, high volume of storm water is generated leaving no scope for ground water recharging making cities more vulnerable to the impacts of the climate change.
- Policy to integrate city master planning & development with lake conservation
- Policy document on urban lakes.
- Motivation citizens and ensuring their active participation
- Ensuring cost effective lake restoration
- Ensuring transparency
- Creating a lake authority.
He also suggests on bringing an Ordinance to check encroachments, as done by the Canadian Government.
The need for protection and conservation of Lakes:
Major portion of surface fresh water is available in lakes / ponds, next to ground water aquifers. The various ecological functions of the lake are:
- Fresh Water Sources.
- Regulates micro-climatic conditions
- Keeps local weather conditions in balance
- Habitat for local and migratory birds
- Supports bio diversity within concrete jungle
- Ecological indicator
- Facilitates recharging of ground water sources
- Regulates flood waters – urban flood mitigating structure.
- Promotes water sports
- Supports water based livelihoods
- Recreation centers
Further there are several challenges to the conventional approaches that need to be addressed. There has been a suggestion that the usage of nualgae helps in rejuvenating the waste water.
Another suggestion was that water from waste treatment plants could be reused for flushing the toilets. In order to reduce severe pollution loads from heavy industries, these industries could have ETPs in their own premises.
Another suggestion made was the usage of sludge to make pavement bricks.
- Lake conservation plans are to be integral components of city master planning & development.
- Governance issues are to be addressed.
- There should be construction guidelines for foreshore and downstream structures.
- All the automobile washing centers should place oil – water filters; separated oil should be sent for safe disposal.
- Motivate & encourage citizens to use environmental friendly
The session concluded with stressing upon the fact that “Lake is nobody’s baby, but it should be everybody’s concern”.