Friday, September 1, 2023

Reconnaissance survey of Nayandanahalli Kere

Nayandanahalli Kere


In our mission at Biome Environmental Trust to foster sustainable water management, we continuously seek opportunities to integrate conventional and modern water-saving technologies. Our most recent reconnaissance survey led us to Nayandanahalli Lake, a unique water body that receives tertiary treated sewage water. This blog aims to detail the findings of our preliminary survey and explore the lake's potential to serve as a pilot for integrated water management systems in urban and rural contexts. 

Location & Accessibility

  Image: The Map shows the location of  Nayandanahalli Lake in yellow and STP in maroon. The light blue line is the Vrishabhavati River. The lake is very near to the Rajarajeshwari Metro station.

  1. Address: Nayandahalli Lake, ITI Layout 3rd Phase, Dr Ambedkar Nagar, Nayanda Halli, Bengaluru, Karnataka 560039  
  2. GPS Coordinates: 12°56'16.8"N 77°31'16.3"E  
  3. Entry Point: Accessible from the main road - Mysore Road  

Recent Rejuvenation and Tertiary Treatment

In January 2023, the lake received a fresh lease of life. Tertiary treated water from the BWSSB Sewage Water Treatment Plant (STP) is now being routed into the lake. This unique approach to wastewater management promises enhanced water quality and could serve as a template for other urban lakes.

Image: Map shows the Two inlets, Waste weir/Outlet, bathroom, and Garden (rectangular Green boundary) of a lake.

Comprehensive Overview of Physical Attributes and Hydrological Parameters

Area: Approximately 34,000 square meters, with a very small island dominated by bamboo trees
Perimeter: About 800 meters  
Depth: 9 feet on the east side and 15 feet on the west side near the outlet or waste weir 
Inlets: Two, one on the east and another on the south, with the east currently active.  
Drainage Capacity: The southern waste weir is fitted with additional pipes and vaults that can be activated to drain excess water

Image: Hydrology and topography map of Nayandanahalli Lake. The map also depicts the location of STP,  the lake, Vrishabhavathi river and a drainage running parallel to the lake. It can be observed that the lake is the only lake in the cascading lake systems. The natural drainage of the area can be seen and the arrows show the direction of flow of water in the region.  

Image: The map shows the way in which treated water from the STP is redirected to the lake, and using a pipeline, two inlets are made at the east and south ends of the lake. Currently, the East inlet is in use, because the water from the south outlet very soon drains out because the south outlet is very near to the waste weir/outlet. The excess water from the lake is naturally drained out of the waste weir and joins the drain that runs parallel to the lake. 

Infrastructural Elements

  1. Walking Path: A 7-foot-wide walking path supplemented by an extra 3-foot-wide buffer zone for plantation  
  2. Open Drains: These are strategically placed to route rainwater from the walking path into the lake  
  3. Stonework: The lake is stone-pitched along its internal periphery, aiding in erosion control  
  4. Flora: A variety of plants including guava, Singapore cherry, and other ornamental bushes
  5. Facilities: 
    24/7 security personnel, Street lighting along the perimeter, Bathrooms situated on the east side, A triangular garden space in the northwest. The presence of a high-tension electricity pole near the lake’s boundary was observed.

Water Quality Assessment

  1. Visual Inspection: The water appears clear with no visible signs of plant or algal growth
  2. Odor Test: A strong smell of chlorine was noticed, but only near the inlet where the STP water is released

Ecological Impact

Nayandanahalli is home to a few species of birds including common moorhens, little grebes, coots, and purple moorhens.

Potential for Future Water Management Initiatives

Given the successful integration of tertiary treated sewage water, Nayandanahalli Lake offers an opportunity for further advancements in sustainable water management. Specifically, its relatively stable ecosystem and recent rejuvenation make it an excellent candidate for integrating shallow aquifers like open wells or filtered bore wells into a holistic water management strategy.

Future steps include comprehensive hydrological and environmental studies to determine the lake's capacity to contribute to the water security of nearby localities.

For more updates on Biome Environmental Trust’s water management initiatives, please stay tuned to our blog and social media channels.

Blog by Ayushi Biswas

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