Monday, September 18, 2017

Rainwater Harvesting in Kasavanahalli Higher Primary School: A collaborative effort

The Rainwater Harvesting was implemented in Kasavanahalli Higher Primary School (HPS) by Biome Trust with financial help from Students of University of Washington and on-field support from the school itself, Ms. Hema from Bhoomi College and our Plumber Manjunath. Below are some details about the implementation and the activities done subsequently when Uni. of Washington students came down to India.

Kasavanahalli Higher Primary school (HPS) is located off central jail road, near the Kasavanhalli village. The total student strength is ~200 and 4 teachers are appointed for the school. The school shares one of the classroom blocks with the Samriddhi Trust. Samriddhi Trust runs a bridge school for children of migrant labours in the vicinity.
In addition, the school also faces major water scarcity. The school has one 10KL sump and plumbing connections given to the overhead tanks (OHTs) for toilets and handwash. However, the main issue is availability of water. This area doesn’t have access to Cauvery water/piped water supply. The school doesn’t have borewell and hence, have to depend on the tanker water for water needs. This incurs expenses which the school finds difficult to manage. Moreover, the toilets are not being used due to lack of water.

Rainwater Harvesting as an intervention emerged through discussed with everyone. The school would be able to harvest ~10KL in one average rain which would suffice them for 3-4 days at least. The University of Washington students in the Leadership Program came down to India and the school to engage with the school. Below are some pictures capturing the components of the system and the student activities.



Monday, September 11, 2017

Puttenahalli JP Nagar Lake Report

Authored by Shreyas Sati and Alana Helin as part of the BIOME Trust Wetlands & Lakes Project

Puttenahalli Lake is on 13 acres, 25 guntas and is located in the south of Bangalore between Brigade Millenium and L&T South City near Millennium Avenue. It is frequented by many local residents who enjoy the provided 1.1 km walking path, horizontal and parallel bars for exercise, gazebo, and other amenities. There are three entry points into the lake premises, one at the northwest and two at the southeast corner. The entire eastern side of the lake is bordered by slum dwellings and is open to nearby roads. There is no STP within the lake premises. However, there is a large area of the lake which is occupied by constructed wetlands, some attached to the lake bed/bund around the lake and some floating. In total, there are 7 inlet points and 1 outlet from the lake. Of those, two are STP treated water from L&T South City apartment complex and five are storm water inlets that flow from neighbouring areas into the lake through culverts. Around the periphery of the lake, there are about 200 trees planted which teems with fish and other fauna.

Overview and Observations
Puttenahalli Lake is located in JP Nagar, 7th Phase, Nataraja Layout Bangalore.

Lake Area
13 acres, 25 guntas
No STP exists. However, Constructed Wetlands exist in multiple locations of the lake
  • A lot of work has been done in constructing wetlands inside the lake by many players which includes: government bodies like BBMP, educational institutions like BMS College of Engineering, Puttenahalli Neighbourhood Lake Improvement Trust, etc.
  • There are 7 inlet points and 1 outlet from the lake.
  • In the mornings and evenings, many local residents use the 1.1 km path around the lake for walking, jogging, or other workouts.
  • We did not observe any buildup of algae on the surface.

The Lake
Seven inlets where water would enter Puttenahalli Lake were identified and are summarized below. All of the inlets except 6 & 7 discharge into silt traps prior to entering the lake or wetlands. In addition, the two STP treated water inlets are filtered through a small grate to capture large debris before it enters the lake (photos below - Inlets 1 & 2).

1 & 2
STP Treated Water
L&T South City apartment discharges approximately 8 lakh liters of its treated STP water into the lake each day at the southeast corner of the lake through two double-culvert structures.
Stormwater Overflow
Stormwater from across the lake at different points as shown in the map enter the lake through culverts.
20170824_073323.jpg 20170824_073801.jpg20170824_075539.jpg

The outlet from the lake is an overflow system under a bridge in the NE corner of the lake.
Overflow outlet from Puttenahalli Lake

There is no STP at Puttenahalli Lake. However, treated STP water from L&T South City is discharged into the lake through two inlets next to each other. Many locals mentioned to us that they observed fish kills when the treated water flow increased. But, it needs to be verified if fish kills occur when the treated water inflow increases or when the rainwater inflow increases. We also observed that there is no smell issue or complaints near the treated water discharge point.

The Wetlands
There are multiple wetlands in Puttenahalli Lake, including constructed wetlands which are floating and/or attached.

Near the entrance in the northwest and the small rest area, there were several floating wetlands.

Floating wetlands were found throughout the lake

In the southeast corner of the lake, the treated STP water from South City passes through wetlands which consist of floating and attached plants.
Constructed wetlands (foreground), floating and attached, to further treat STP water from South City

There is also a wetland prior to the outlet which further filters water before it leaves the lake.
The lake water flows through the wetland and discharges through the outlet which is to the right of the picture above.

Contact Info
Puttenahalli Neighbourhood Lake Improved Trust (PNLIT) :,,, +91 7259722996, +91 80-41206057


Agara Lake Report

Authored by Shreyas Sati and Alana Helin as part of the BIOME Trust Wetlands & Lakes Project

Agara Lake is on 90 acres and is located in the southeast part of Bangalore near Sri Jagannath Temple in Agara Village. Of the total 90 acres, the main lake area is 61 acres. It is frequented by some local residents who enjoy the provided walking path. At present there is no STP. However, there is a 8.5-acre space in the southern part of the lake allotted for a constructed wetland. The wetland has 5 parallel bunds which stops the direct inflow of wastewater into the main part of the lake. In total, there are 17 inlet points and 1 outlet from the lake. Of those inlets, 14 inlets are from a stormwater drain along Sarjapur Road and one inlet is from the kalyani near the proposed children’s play area, both of which enter the main lake directly. The remaining two inlets enter the wetland; one large naala in the south directly enters the wetland and one storm drain enters from the east into a silt trap prior to entering the wetland. The outlet of the lake is an overflow weir under a bridge in the western corner of the lake. N: Naala, I: Inlet. Map labels match up with corresponding legend element. Top of map is north.

Overview and Observations
Agara Lake is located near HSR layout, Sarjapur Road, Bangalore.  20170818_075528.jpg

Lake Area
90 acres
None. Provision for constructed wetlands is made.

Karnataka Lake Conservation and Development Authority, some private players like Souharda Infratech Pvt Ltd, Alcon Consulting Engineers (India) Pvt Ltd and the local community are working towards restoring the lake and have spent about Rs. 6.25 Crores in Phase 1 of the project. It is estimated that the total cost of the project will be about 16 Crores. The proposed plan of lake restoration is as shown in the picture below.

However, we observed that the work is still in progress and much of it is yet to be completed. Also, there are minor deviations in implementation from the proposed plan in terms of location of the inlets and amenities.  

There are 17 inlet points, fifteen of which discharge into the lake directly and two enter the lake through the wetlands. It was reported by a resident that a sewer line runs under the walking track which is adjacent to the 14th Main road and the large naala (Naala 1), which flows into Bellandur Kere.


In the mornings and evenings, few local residents use the 2 km path around the lake for walking, jogging, or other workouts. Currently, there are multiple benches around the lake and a boat jetty. It appeared that three toilet facilities and a kalyani were under construction at the time of our visit.

We also observed several semi-permanent housing structures and tents along the southeastern portion of the walking path.

The Lake
Seventeen inlets where water would enter Agara Lake were identified and are summarized below.
Naala 1 Flow
Sewage from Begur, Madiwala, Rupena Agrahara, and Bommanahallli regions flow through this Naala 1 and enters the wetlands through an automated gate.
Storm Drain Flow
Mix of storm drain and sewage flows from the east of the lake into silt trap which further enters the wetlands and the main lake.
Kalyani Outlet
A kalyani is being built at the north side of the lake in proposed children’s play area/Agara Park. The outlet of the kalyani is an inlet into the lake.
Stormwater Overflow
14 inlets along the Sarjapur road carry storm water which enters a settling chamber and overflows into the lake.

The outlet from the lake is an overflow weir under a bridge in the western corner of the lake. The water which overflows would enter Naala 1 and be directed to Bellandur Lake.

Overflow outlet from Agara Lake

There is no STP at Agara Lake. However, we were told by some people who live there that there is a proposal to commission a 35 MLD STP at a cost of 65 crore1, the details of which is not known. According to an April article in The New Indian Express, the STP will take two years to complete after the tender is awarded1. We were also told that the sewage flowing in the large Naala 1 would be diverted through an underground drainage pipe to Bellandur lake which would reduce the sewage flow in the naala by about 60-70%.

The Wetlands
There is a provision for building a 8.5 acre constructed wetland. Currently, the wetland region is divided into 5 zones separated by rock bunds. The sewage from Naala 1 enters the 1st Zone of the wetland and the wastewater from Inlet 2, which is the storm drain flow, enters the 5th Zone of the wetland through the silt trap.  

Contact Info
LDA : 080 25590097,
Agara Lake Protection & Management Society : President - 9880091609, Gn. Secretary - 9901018957,
Kavita Reddy : 98453 98118,


Open Questions
  1. Where does the sewer line originate and where does it go?

Saturday, September 9, 2017

Alahalli Lake Report

Authored by Shreyas Sati and Alana Helin as part of the BIOME Trust Wetlands & Lakes Project

Alahalli Lake, also called Avalahalli Lake, is on 23 acres and is located in the southern part of Bangalore next to Amruth Nagar Main Road and Nandi Gardens Apartment Complex. It was observed during our visit on 8 September 2017 that the lake is not frequented by local residents but is used as a point of transit from one point to another. There is a small walking path on the northern boundary and partly on the eastern boundary which is currently submerged by water. No other amenities exist in this lake. Neither STPs nor wetlands exist in this lake. In total, there are 6 inlet points and 1 outlet from the lake. All the 6 inlets flow directly into the lake without treatment. The volume of inflow through the inlets is significant but could not be determined.


Alahalli MyMap.png

Overview and Observations
Alahalli Lake is located in Anjanapura township, Bangalore.

Lake Area
23 acres
Neither STPs nor Wetlands exist in this lake

Alahalli Lake & Neighborhood Development Trust (ALNDT), the local corporator K. Somashekar, Pavitra Foundation, PROMAC Industries, and a few residents nearby have put efforts in the direction of rejuvenating the lake. Together they have spent about Rs. 20 lakhs for de-weeding, constructing a 100 meter walking path, repair and maintenance of fences, operation and maintenance. There are six inlet points, all flowing directly into the lake without being treated, and one outlet from the lake which flows to Vaderahalli lake.

We observed that the health of the lake is very poor from the point of view of the quality of lake water. We could see algal growth on the majority portion of the water and is a breeding ground for various organisms. We also observed gas bubbles coming out of water as a result of anaerobic reactions. Along the northern boundary of the lake, from 2 broken chambers, we could see wastewater flowing into the lake through the surface of the walking path (POI 1). Due to these reasons, people may not like to use the lake for any recreational purposes.

It was also pointed out that a irrigation structure is in the lake along the western edge (POI 2). This structure was used to take water from the lake from irrigation in the past.

Despite the ongoing problems, the ALNDT is working hard to educate people in the neighborhood about the ecological benefits and the need of a healthy lake. They are also trying to mobilize resources from government authorities and private parties for rejuvenation of the lake.

The Lake
Six inlets where water would enter Alahalli Lake were identified and are summarized below.
Naala 1
Discharges directly into the lake through a culvert without any treatment from the Amruth Nagar Main Road.

Naala 2
Discharges directly into the lake under a bridge without any treatment from houses and apartments of Alahalli.

As seen in the bottom photo, a small grassy bund slows the sewage inflow and allows for some settling to occur before the water flows into the main water body.
3 & 4
Naala 3 & 4
Discharges directly into the lake through a culvert without any treatment from small houses/apartments, which are to the east of the lake.
Naala 5
Overflow from Kembathalli Lake discharges directly into Alahalli Lake through a culvert without any treatment.
Naala 6
Discharges directly into the lake without any treatment from Gollahalli.

The outlet from the lake is an open channel in the SW corner of the lake. The weir has been demolished by nearby residents who feared flooding by high water levels.
Outlet channel from Alahalli Lake

Buildup of algae on the surface was very apparent on the majority of the lake.

Near the northwest entrance, there are multiple pictures of gods placed next to a peepal tree.

The lake trust has hired two labourers for maintenance at an approximate cost of Rs 20,000/- per month. These labourers regularly use a trash boom to remove debris from the lake while on a small coracle.

No STP exists in the lake premises.

The Wetlands
No wetlands exist in the lake.

Contact Info
ALNDT Member: Anand Yadwad : +91 98802 44380,

References & Resources