Understanding HalanayakanaHalli lake

This document attempts to understand the Halanayakanahalli Kere and the cascading lake system that it is part of, its current state and its effects on the environment.

1. Halanayakanahalli Kere
Halanayakanahalli kere lies in the Sowl kere watershed and is part of the cascading tank system that is upstream of Sowl
kere. The lake is surrounded by busy public roads on all sides and hence open to public at all times. It lies to the north of
Rainbow Drive and is one of the sources of the flooding that the gated community experiences during heavy rains.
On 14
th
December 2022, Biome along with members of the RBD went around Halanayakanahalli kere to survey the area to
see what can be done to improve the flooding issue. This document outlines the findings from that undertaking.

2. ●Overview of Halanayakanahalli Kere
●Halanayakanahalli Kere
●Temporal changes of Halanayakanahalli Kere
●Topography/Elevation map of Halanayakanahalli Kere
●Natural Drainage map of Halanayakanahalli Kere
●Watershed of Halanayakanahalli Kere W.R.T Rainbow
Drive
●Observations after survey for Halanayakanahalli Kere
●Natural drainage and watershed of Junnasandra kere
●Observations after survey for Junnasandra kere
Content

3. Overview of Halanayakanahalli Kere
Saul Kere
Bellandur Kere
Varthur Kere
Halanayakanahalli Kere
●The Halanayakanahalli Kere
is part of the Saul Kere’s
Watershed. It is one of the
Upstream lakes of Saul Kere.
●The drainage flow is from
South to North.
●The Kere covers an area of
approx 64.7Ac at an
elevation of 890 mts above
sea level.
●It has two upstream lakes
Choodasandra Kere,
Hadosiddapura Kere.

Natural Drainage network and watershed is
created using SRTM DEM data dated Feb
2000. Lakes, watershed outlines are
mapped manually using LANDSAT satellite
data.
Drainage Flow
Direction

4. Observations based on
Satellite Data

●In 2002 - Command Area
was approx 8.39 Ac.
●Since 2002 it is observed
that the Kere had small
command area
●Most of the downstream
area near the kere has
always had more trees
than crop/irrigation.


The inlets, Outlets, Command area are
all mapped manually using satellite data
based on LANDSAT DATA Dated January
2002
Halanayakanahalli Kere in 2002
Command Area
Halanayakanahalli Kere
Choodasandra Kere Hadosiddapura Kere
Inlet
Inlet
Inlet
Sluice gate Kaluves
Inlet
Drainage Flow
Direction
Sluice gate

5. Temporal changes in Halanayakanahalli Kere
Timeline
2002 > 2014 > 2022

6. Halanayakahalli Kere part of Saul Kere watershed in 2002
2002
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Quarry
Lakes
Inlets
Sluice Gate
Outlet
Command area
Sarjapura Road
Junnasandra Kere

7. 2014
Halanayakahalli Kere part of Saul Kere watershed in 2014
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Old Quarry
Lakes
Inlets
Command area
Sarjapura Road
Junnasandra Kere

8. Halanayakahalli Kere part of Saul Kere watershed in 2022
2022
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Old Quarries
Lakes
Inlets
Command area
Sarjapura Road
Junnasandra
Kere

9. Topographic and Elevation map of Halanayakanahalli Kere
Ridges of the watershed
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Saul Kere
●The highest points (Ridges) of the watershed
are at 920 masl and the kere is at 890 masl.
●While the downstream area of the kere is at
elevation of 885 masl.
●The region from the HalanayakanaHalli kere
downstream to Saul kere across the
Sarjapura road (indicated in Red arrow)
●The slope gradient (change in slope) is only 5
meters over a distance of approx 1.8km
making it a area with very gentle slope.
Drainage Flow
Direction
The elevation, contours and natural drainage maps are created
using SRTM DEM data dated February 2000. The lakes are mapped
manually using LANDSAT Data.
Junnasandra Kere

10. Halanayakahalli Kere
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Ridges of the watershed
●It is observed that in the events of rainfall for
long hours or heavy rainfall in very short period
of time (called as cloud bursts) causes:

1.The water overflows over the bund which
is a road now.
Reasoning: Can be due to elevation of waste weir
higher than required/thin outlet? choked outlet?

1.The runoff happens in sheet form.
Reasoning: Can be due to absence of any
natural/artificial channels/ drainage and gentle
sloping of the downstream area causes the sheet
flow?
Drainage Flow
Direction
Junnasandra Kere
Saul Kere
Wastewater
Sluice gate

11. Major and Detailed Natural Drainage map of Halanayakanahalli Kere
The natural drainage lines are created using SRTM DEM satellite data. The detailed and Major
drainage show the natural drainage pattern with respect to the topography and elevation
Major drainage Detailed drainage
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Saul Kere
Bellandur Kere
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Saul Kere
Bellandur Kere
Junnasandra Kere
Junnasandra Kere

12. Halanayakanahalli Kere Watershed
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Inlet
InletJunnasandra Kere
Drainage Flow
Direction

13. Junasandra Kere and HNhalli Kere Watershed
Watershed
Halanayakanahalli Kere
Choodasandra Kere
Hadosiddapura Kere
Junnasandra Kere

14. Drains passing through Rainbow Drive
Rainbow
Drive Halanayakanahalli Kere
Choosandra Kere
Hadosiddapura Kere
Junnasandra Kere
Drainage Flow
Direction

15. Flow from Junasandra lake
and neighbourhood houses
Sluice Gate
Solid Waste Dumping
Inlet-1
Inlet-2
Inlet-3
RBD
Junasandra Lake
Merge of Junasandra
and HKhalli Lake
Overflow

16. 1.Solid waste was dumped in and around the Lake and at the inlet of the drains (refer previous slide for
dumping points).
2.Cleaning of the Lake can be taken as an immediate action to improve the health of the lake
3.No direct sewage water entries into the lake was found but an eye needs to be kept on this in future
visits as this these channels are not controlled/protected in any way.
4.Neighborhood houses and apartments are letting their sewage water into the stormwater drains.
5.The stormwater drain connecting Junnasandra lake and Halanayakanahalli lake flows into the Rainbow
drive layout; this Nala needs to be extended to direct this water to drains that connect to the Sarjapur
road stormwater drains.
6.The sluice gate is dysfunctional though, water might still be moving to the command area through this.
7.Outlet channel is blocked by a road (as seen in the previous slide). Hence, overflow from the lake floods
this and other connected roads in area.
Pointers after Halanayakanahalli Kere Survey

17. Thank you