Decentralised Waste Water Treatment > Case Studies

Hebbal Nagwara Valley Project - Bengaluru, Karnataka

 
Key Highlights of the Projects
 
Year of Commission

2016
Total Installed Capacity 130 MLD
Total Utilization Capacity 130 MLD
Treatment Technology Sequencing Batch Reactor with tertiary treatment
Current Reuse Thermal Power Plant (Cooling Purpose)
Volume of Water Reuse Daily 130 MLD (Tertiary Treated)
Quality of treated water (Outlet) pH- 7.4. BOD-3.6mg/l, COD-11mg/l, TSS-2.3mg/l
Economics NA
 
Site Overview
 

• Chikkasagarahalli Lake is in Karahalli village, Devanahalli Taluka, Bengaluru Rural district, Karnataka.
• Karahalli is 15 km from Devanahalli (sub-district HQ) and is a gram panchayat.
• Total geographical area: 581.83 hectares; population: 2,152 (2011 Census).
 
Agricultural Practices and Water Challenges
 

• Farming is the primary occupation; relies on open wells and borewells for irrigation.
• Declining groundwater levels have caused wells to dry up, forcing farmers to depend on rainfed irrigation or tanker water.
• Chikkasagarahalli Lake plays a vital role in recharging wells but had also dried up, leading to abandoned wells.
• Main crops: floriculture (marigold, rose) and vegetables (tomato, beans, cauliflower, coconut).
 
Impact of HN Valley Project (2021)
 

• Lake desilted and deepened to enhance storage and capture runoff.
• Treated used water released into the lake ensured a consistent water supply for aquifer recharge.
• Wells naturally revived, providing sustainable irrigation water.
 
Agricultural Revival (2022)
 

• Farmers resumed growing crops: marigold, rose, tomato, beans, cauliflower, coconut, bajra, and potato.
• Wheat and rice cultivation unsuitable due to the regional climate.
 

 

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