Restoring Bangalore’s Ulsoor Lake

Some Ecological Considerations in Restoring Ulsoor Lake of Bangalore. Dated 29^th March 2003.

 

There is:

1. A need to go beyond viewing Ulsoor lake as a place for play
2. Need for an accurate evaluation of the deepening of the lake
3. Need for a Sloping Shoreline
4. Need for Vegetational Diversity in the lake
5. Need for a Green Screen around the lake
6. Need for an Educational Display Centre

A need to go beyond viewing Ulsoor lake as a place for play

Lakes and tanks are very important landscape elements which need to serve multiple uses. They are as much places for urban wildlife and education as they are points of ground-water recharge. Therefore, a lake like Ulsoor, need not just be a place for play. If one considers boating for example, given local conditions, rescue in the case of a mishap in any lake larger than around 10 hectares, becomes extremely difficult. Dunking people in polluted lakes with high bacterial loads and faecal coliform contamination is also not advisable. Therefore Ulsoor lake needs to be converted into a place for informal learning and illustration where a relaxing ambience pervades and children could learn and get informed about issues at their own pace. Could the Army and the Navy have a role here?

Need for an accurate evaluation of the deepening of the lake

Wet clayey earth shrinks on drying. This is also true of lake bed sediments. An exposed lake bed, by mere virtue of being dried, could give an impression of having been deepened. Therefore, removal of silt has to be systematically monitored by amount of earth removed and not by comparing ground level differences before and after renovation. Mere level differences between the wet and dry lake bed should not be used as a measure of silt removed.

Need for a Sloping Shoreline

The life of a lake or tank is in its shoreline. Many animals and plants make use of this sloping shoreline where light penetrates to the bottom, to live and reproduce. An entire animal community lives in the shallows. Birds like egrets, herons, sandpipers, storks and stilts, just to name a few, feed in the shallows. A slope more gradual than 1:5 is essential for the purpose. The shoreline of the islands need to be modified and also some chosen portions of the lake.

Need for Vegetational Diversity in the lake

The Ulsoor lake, to be healthy in the long run, cannot be maintained like a tub of water. It needs to have different kinds of macro-plants with different structures. Submerged vegetation, emergent vegetation, anchored floating vegetation and floating vegetation comprising of appropriate species in suitable parts of the lake would be essential to maintain and sustain the life giving processes of the lake. Ulsoor lake would even need trees in standing water, which is possible. All these would add to the aesthetic value of the lake.

Need for a Green Screen around the lake

The Ulsoor lake needs to have a ‘ring’ of trees and tall hedge around it, bordering the roads, especially where there is movement of traffic. This would lessen visual disturbance and noise. A partial broken ring of trees in standing water would provide additional feeding and roosting substrates for birds.

Need for an Educational Display Center

The Ulsoor Lake could have a small display centre highlighting the value of water bodies in an urban situation. This should serve to educate the visiting public. The value of such tanks for the Army and Navy’s training purposes should also be highlighted. Topics addressed for example, could even cover questions like “How is a bathymetric survey done?” Could the Army and the Navy have a role here?

 

[29^th March 2003. Asked for by Admiral O. S. Dawson who was interested in the lake]