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.
Challenges faced:
- 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.
It also
- 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.
Conclusions
- 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
“Detergents”.
The session
concluded with stressing upon the fact that “Lake is nobody’s baby, but it should be everybody’s concern”.
