The document discusses the importance of proper lake rejuvenation for both human enjoyment and bird habitats. It contrasts poor practices, such as replacing natural sloping banks with concrete walls, which harm bird populations, with successful examples that incorporate natural features to support wildlife. Key design principles for lakes in Bangalore include creating safe environments for birds and minimizing concrete use to preserve natural ecosystems.

1. Lake rejuvenation
how not to do it
GV Dasarathi
dasarathigv@gmail.com

2. We need these visitors in our lakes
They add immensely to the beauty of a lake,
and give us joy.

3. What do these birds need ?
They need a sloping mud bank with reeds growing, to feed, nest
and live.
The banks must be reasonably far from human movement, so the
birds feel safe.

4. Example of bad 'rejuvenation' – Sankey Tank
Sloping mud bank was replaced by vertical concrete walls.
3 large islands wih trees and grass were removed – just one small
island remains, with a single dead tree.
This removed almost all the living and nesting areas of birds.
Hence the zero birds in this picture.

5. Example of bad 'rejuvenation' – Sankey Tank
A sanitized lake – most prominent feature is the brown concrete.
The only birds seen are Cormorants that sit on trees beyond the bank, and
do not need shallow water to live and feed in.
The water reflects the brown of the walls and the blue of the sky,
so you have blue-brown coloured water.

6. Example of good rejuvenation – Puttenahalli
lake
Walking path for humans, with a sloping mud bank beyond it leading to
the water.
No vertical walls enclosing the lake.
The water reflects the green of the bank and the blue of the sky, so you
have blue-green coloured water.

7. Result – a paradise for birds and bird watchers

8. Some basic design rules
to follow in Bangalore's lakes
1. Design for humans, birds and aquatic life, not just humans.
2. Walking path on outer periphery, then sloping mud bank
leading to the water.
3. Humans do not have access to the mud bank – it is fenced off.
4. Ensure that there are islands in the lake, with trees. If necessary,
ADD Islands.
5. Minimize the use of stone and concrete. It heats up the place,
while mud, reeds and water keep the place cool.