The Jakkur Lake

WATER FOR SUSTAINABLE AND INCLUSIVE CITIES BENGALURU- IS GOING LOCAL A WAY FORWARD ? AREA- 1250 km sq. POPULATION- 9.5 million ELEVATION- 900 M.S.L. WATER SUPPLY- Currently, Bengaluru gets its water from the Cauvery River, 95 kms away and 300m below the city. 1310 MLD is pumped into the city and that is the ceiling. EMBODIED ENERGY- Pumping water to the city results in an embodied energy of 1.88 units per kilo Lt. WASTE WATER- 24 Sewage Treatment Plants will treat about1100 MLD CONTEXT- BENGALURU KEY : Ceiling on water availability hence a search for alternatives in the short term Unaccounted for Water reduction (Project on for physical loss reduction and financial loss reduction) Rainwater harvesting (Law in place making it compulsory for new constructions ) Groundwater management (Law in place for groundwater regulation) Wastewater reuse (Law in place for compulsory treatment pant and recycling for more than 20 apartments / houses) Rainwater harvesting • The city Bengaluru receives 970 mm on average annually • This is spread over 8 months and 59 rainy days • The equivalent rainwater endowment on the city is 3000 MLD as against Cauvery water supply of 1400 MLD Rainfall pattern in Bangalore Maximum rainfall intensity 90 mm/hour 30 years data MONTH DAYS QUANTITY (mm) JAN 0.2 2.70 FEB 0.5 7.20 MAR 0.4 4.40 APR 3.0 46.30 MAY 7.0 119.60 JUN 6.4 80.80 JUL 8.3 110.20 AUG 10.0 137.00 SEP 9.3 194.80 OCT 9.0 180.40 NOV 4.0 64.50 DEC 1.7 22.10 TOTAL 59.8 970.00 Hydro-flows from a small plot Before building After building • Surface runoff 15 % 90% • Recharge 10 % 5% • Evapo-transpiration 75 % 5% • The aim of rainwater harvesting is bio-mimicry. • To restore the local hydrology on a plot as before building The new rainwater harvesting bye-law for Bangalore City • For every plot create recharge or storage – @ 20 litres per square metre of roof area – @ 10 litres per square metre of paved area Minimum depth of recharge well 3 metres EVERY ROOF IN A CITY CAN BE A CATCHMENT A rain barrel is the simplest way to harvest rainwater Rainwater harvesting in an underground tank Muniappa the well digger who has dug more than 2000 recharge wells Tanks- Artificial water bodies built by throwing an earthen berm across a valley to store water for irrigation purpose Jakkur Lake Catchment– 18.9 sq. km Water spread-50Ha TANKS OF BENGALURU – New role of Integrated Urban Water Management with Citizen participation THE JAKKUR LAKE BDA BWSSB BBMP KLDA PCB FISHERIES FOREST GROUND DEPARTM DEPARTM WATER ENT ENT AUTHORITY BDA: Bangalore Development Authority – has Karnataka Lake Development Authority: Is developed the lake with desilting , fencing etc responsible for lake protection BWSSB: Bangalore Water and Sewerage Board : Pollution Control Board: the regulator of lakes runs the Sewage Treatment Plant and STP’s BBMP : Bruhat Bengaluru Mahanagara Palike: owns the lake Fisheries Department: responsible for the fisheries contract Forest Department: responsible for off lake plantation Groundwater Authority: monitors groundwater extraction around lake Currently a citizens group Jalaposhan- manages the lake with an MOU with the BBMP INSTITUTIONS & LAKE OWNERSHIPS-Fragmented. 1 2 3 1.STP 2.WETLAND 3.THE LAKE JAKKUR & ITS ECO SYSTEM – A Sewage Treatment Plant, a constructed wetland and water-spread LIVELIHOOD : Fishing , cattle grass collection, greens for food, clothes washing. Sludge sold as manure. CULTURAL : Worshipping , Ganesha Idol immersion and place for rituals LIVELIHOOD & CULTURAL • A water balance study shows a daily recharge of 7.25 million litres (Inayathullah et.al) • A study on the constructed wetlands performance indicates reduction ~45% COD, ~66 % BOD, ~33 % NO3-N and ~40 % PO4 3—P (T.V.Ramachandra et.al.) • A study on sludge reuse suggest good crop growth with high presence of Phosphates (Srinivasamurthy et. al.) • A Citizens group can take ownership of a lake and can bring institutional convergence to its management • Livelihoods integration is possible through stakeholder engagement LEARNINGS • The correct functioning of the Sewage Treatment Plant and managing the constructed wetland is difficult. • Raw sewage entry from storm water drains occasionally is a problem. • Encroachment of connecting storm water drains between lakes can disrupt catchment to lake link. • Long term stability of Citizen Group. • Absence of a single Integrated Urban Water Management Institution. CHALLENGES • Replication has begun in a few lakes including one with Corporate Social Responsibility and will need to reach all the remaining lakes of the city. • Will assist in the formulation of a waste water policy in the city/state. WAY FORWARD…. In many apartments a daily visit Nutrient value is recovered But how to avoid soil and groundwater pollution ? Nutrient analysis in progress Farmers have understood the nutrient value The crop The fruits Vijaypura- falling groundwater tables Waste-water from the city Used productively Growing vegetables too Key challenges • Absence of an urban water and sanitation policy • Institutional coordination • Evolving legal framework development ..for eg. With lakes • Institutional capacities Contact : [email protected] Twitter : @zenrainman.

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