Bengaluru Urban

A North-South surface elevation profile of the watershed

The elevation difference between highest and lowest point is 42 m over a span of 9 km

L

-Geology (static)-Field mapping-Secondary data (interviews)-Drill logging (Real time/interviews)

-Water levels (dynamic)-Measured in-situ (or Crowd-sourced)- Water struck at drilling (interviews)

-Water Quality (dynamic)-Measured in-situ (or Crowd-sourced)-Lab testing

-Resistivity survey, Pumping tests

Data is being gathered on the following fronts

Hydrogeology plays an important role in understanding groundwater resources. Hydrogeological studies involve mapping different geologies and different structures within them. The entire project area being a granitic terrain, the mapping process is focused on weathered and fractured zones.

Road cuttings, rock quarries and foundation dugouts are being studied to gather information on the sub-surface geology

Geological mapping

The depths at which groundwater was struck during drilling is found to be far deeper than the current levels of groundwater in many borewells in the study area. The scientific reason being most of the deeper groundwater systems are under confined conditions i.e. groundwater stored within these aquifers is under continuous pressure. When a borewell is drilled into these aquifers, groundwater finds a way to move towards areas of low pressure (i.e. atmospheric pressure) and rises upwards in the borewell

Water levels in borewells

Water level contours – April 2014

Red- all wellsGreen- wells used for water level contour map

-A water level contour map created for select borewells (green) measured in April 2014

-The areas in yellow indicated shallow water levels as against grey areas which show deeper water levels in borewells

- Maps like these will be created for periodic water level data sets to understand groundwater movement in the study area

Red- all wellsGreen- wells used for water level contour map

Water level contours – December 2014

Water level 3D – December 2014

Geological variations in the study area

Methodology

LattitudeLat. In degree Longitude

Long. In degree

Elevation(m)

Depth(m)

Casing(m)

SWL(m)

1st WS(m)

2nd WS(m)

3rd WS(m) pH TDS Sallinity EC Diameter(DW) Owner/ Address

12 54.669 12.91115 77 41.687 77.69478 893 60 nearest dugwell 1 and near the periphery of the lake

12 54.797 12.9132833 77 41.808 77.6968 898 83 Vishvanath

12 54.939 12.91565 77 40.762 77.67937 888 304.8 57 289.56 7.38 930 660 1326 1.5 yrs. Old Suburamms@gmail.com

12 54.93 12.9155 77 40.718 77.67863 885 33.2 7.16 920 700 1345 marutinager,house 15

12 55.033 12.9172167 77 40.67 77.67783 891 365.76 32 17.6 18.28 243.84 7.25 920 700 1361 Pump running for 10hrs. Abhee Construction- Nagaraj

12 55.005 12.91675 77 40.668 77.6778 892 259.08 19.8 11.1 97.536 198.12 213.36 Eleven months old Abhee Construction- Nagaraj

12 53.862 12.8977 77 41.75 77.69583 904 335.28 39.624 100 60.96 182.88 243.84 vandana constructions

12 53.884 12.8980667 77 41.711 77.69518 908 335.28 39.624 50 60.96 182.88 243.84 vandana constructions

12 53.853 12.89755 77 41.732 77.69553 902 335.28 39.624 15 60.96 182.88 243.84 vandana constructions

12 53.914 12.8985667 77 41.548 77.69247 897 43 inside the lake near school

12 53.882 12.8980333 77 41.565 77.69275 892 44 inside the lake near school

12 53.861 12.8976833 77 41.606 77.69343 894 57 inside the lake near school

12 53.545 12.8924167 77 41.933 77.69888 904 40 Skanda shelters layout

12 53.611 12.8935167 77 41.904 77.6984 903 140.2 43 10 to 15 yrs. Old Skanda shelters layout

12 53.573 12.8928833 77 41.924 77.69873 900 34 Skanda shelters layout

12 53.594 12.8932333 77 42.014 77.70023 900 112.776 30.48 23.3 24.384 109.728 10 to 15 yrs. Old, 1.5 inch of water in 1st year Skanda shelters layout

12 53.628 12.8938 77 41.997 77.69995 898 109.728 24.384 23 Skanda shelters layout

12 55.377 12.92295 77 41.323 77.68872 883 40 around the border,on the eastern side of lake and middle of the eastern side

12 54.975 12.91625 77 40.374 77.6729 877 12 7.5 9.4 priya's house

12 54.98 12.9163333 77 40.449 77.67415 893 335.28 30.48 60 12.192 near fire station( bigger cons. Site) sirnivas classic

12 55.026 12.9171 77 40.476 77.6746 882 304.8 30.48 11.3 274.32 contaminated water near fire station( bigger cons. Site) sirnivas classic

12 54.321 12.90535 77 39.963 77.66605 884 304.8 18.288 7 106.68 FRACTURED ROCK 24.384, 3hp motor to the west of Eastwood township,on border of lake

12 54.649 12.9108167 77 40.074 77.6679 889 106.68 12.192 25 48.768 60.96 same as BW 39, and nearer to Boutique residency, to the east of residency

12 54.697 12.9116167 77 40.012 77.66687 895 225.552 12.192 44.3 36.576 204.216 near junction of 7th main road and 1st Ave road.

12 53.936 12.8989333 77 39.78 77.663 888 304.8 12.2 north of lake dew(house construction)

12 53.974 12.8995667 77 39.795 77.66325 895 213.36 14.3 north of lake dew(house construction)

12 53.948 12.8991333 77 39.848 77.66413 886 5.8 north of lake dew(house construction)

12 53.551 12.8925167 77 39.371 77.65618 908 243.84 12.192 33 60.96 (empty plot near Varayan Reddy)near the road

12 53.536 12.8922667 77 39.371 77.65618 908 304.8 12.192 35 164.592 (empty plot near Varayan Reddy) near to the wall

12 53.568 12.8928 77 39.371 77.65618 899 23.7 varayan reddy - opp. Side of the road(in the grass patch)

12 53.522 12.8920333 77 39.997 77.66662 922 62.5 on silver county road, to the east of sobha cinnamon

12 53.499 12.89165 77 40.022 77.66703 931 44.1 on silver county road, to the east of sobha cinnamon

12 53.387 12.8897833 77 40.167 77.66945 923 14.1 before the junction of silver county Rd. and Kasavanahalli Rd.,south

12 52.478 12.8746333 77 40.757 77.67928 910 304.8 30.48 39.5 152.4 304.8 roadside on junction at north most tip of lake

12 52.588 12.8764667 77 40.801 77.68002 908 289.56 48.768 57 48.768 one year old, worked for two months nearer to the road

12 52.52 12.8753333 77 40.658 77.67763 900 152.4 49 152.4 7.75 640 450 910 yield 2 inch/hr, daily pumping- 5 times for 20 minutes Bhavya's well, near some sort of big Workshop

12 53.219 12.8869833 77 40.84 77.68067 898 350.52 24.9936 30 54.864 289.56 4yrs old, 1hr pumping for 3 to 4 months Ratna's BW,to the east of lake,on east side of road,closest to the road

12 53.307 12.88845 77 40.571 77.67618 897 30.5 2 months old, yield- 2 inch Panchayat BW

12 53.289 12.88815 77 40.674 77.6779 920 28.8 near disputed home with full RWH,near the house build with mud bricks

12 53.899 12.8983167 77 41.054 77.68423 911 259.08 43.2 8.4 610 440 885 in green house with large tank and iron gate at enterance

12 53.038 12.8839667 77 39.624 77.6604 910 457.2 30.48 68 396.24 to the west of parapana Agrahara lake,and near to a house

12 53.018 12.8836333 77 39.623 77.66038 910 457.2 45.72 27 to the south of borewell 66

12 53.119 12.8853167 77 39.604 77.66007 918 259.08 16.764 78 259.08 construction site to the north of 66th BW

12 53.122 12.8853667 77 39.621 77.66035 918 259.08 16.764 98 259.08 Muddy water construction site to the north of 66th BW

12 52.873 12.8812167 77 39.588 77.6598 911 15.5 Kiriya prathamik prashala

12 52.311 12.87185 77 39.66 77.661 933 304.8 36.576 32.2 243.84 274.32 yield- 1 to 1.5 inch, all shallow springs are dry same owner as 73rd BW,construction adjecant to his house,S-W of Sai Shree Layout

12 52.509 12.87515 77 40.107 77.66845 932 365.76 45.72 34 289.56 same as BW-74 community BW,to the north of BW74, to East of Sai Shree Layout

Data representation in Excel

A hydrogeological layout of the study area

Borewells

The hydrogeological section above has been constructed using a combination of data on field geological mapping and narratives on depths at which water was struck during drilling the borewells. From data collected so far and making inferences from the above section we are able to make out 3 distinct groundwater bearing zones. These zones correspond to confined aquifer systems, but further data and analysis is required to confirm the same. Horizontal openings/fractures and intense weathering along these fractures are characteristics of these confined groundwater systems. Water levels in select borewells are being monitored periodically. Water level contour maps and inferences from water level fluctuations would throw more light on understanding aquifer extents and boundaries