The Importance Of Groundwater In Urban India: S. Vishwanath

The importance of groundwater in urban India S.Vishwanath Advisor Arghyam

Urban India 2001 • 285 million (27.8%) of 1.02 billion • 5161 cities • 35 metros - million plus • 388 large towns • 4738 small and medium < 10 lakhs • Projected 368 million by 2012

Photo : Norma Angelica Hernandez Bernal

Groundwater.....provides for the poor , since the poor are usually not connected to the piped water supply

Water from a recharge well

What does urbanization do to urban groundwater? •Increase it in the core area through leaking pipes (50%) and uncollected sewage •Impair quality through point/non-point pollution •75% of surface water is polluted by untreated municipal waste water

Typology • Lithology determines typology • Coastal • Hilly • Hard Rock • Alluvial • Arid

Groundwater dependence • 75 % of urban areas in alluvial areas depend on groundwater • 80 % of cities in hard rock areas depend on external surface sources of water • - Ankit Patel,S. Krishnan

But water is a state subject..

Karnataka • 223 towns • 46 completely dependant on groundwater • 137 partially dependant on groundwater • Bangalore (pop- 6.6million) for example has 20 to 40 % dependence on groundwater but is counted as non groundwater dependant

The issue in cities • Exploding water demand in cities • Problems of urbanization : water shortage and flooding • Need to manage water in cities holistically Case study of a city as an example

Realities • New paradigm required • Multiple sourcing of water • Source control for flood management • Institutional coordination • People’s participation in solution’s • More space for ‘softer’ solutions like education Water tanker Bore well

Water in the city Lakes and tanks : 261 in 1960 81 in 1997 55 in 2000 Lake development authority created to preserve and enhance surface water bodies in city

The Cauvery river basin Bangalore

Groundwater use • Impacts surface flows – The Arkavathy river, 4000 sq km catchment, is now dry. • 150 MLD supply source is now finished • This water now must come from groundwater within the city or from another surface source

Surface water • 800 mld is pumped 300 meter high • 80 MW of energy is used • 200,000 bore wells pump groundwater from 100 to 300 metre depths • ? MW of energy • The gw energy nexus

Local hydrologic cycle

The change • Before construction After construction • Runoff 15 90 (75) • Percolation 10 5 (-5) • Evapo-transpiration 75 5 (-70)

Rain barrel : Does storing water from rain reduce pumping of water?

What should be the quality of recharge water?

Sub-optimization is inevitable

Price will determine use • Bangalore – Rs 72/ KL for industrial water • Resulted in resource substitution – about 100 mld less demand on BWSSB , which presumably came from groundwater • Open well Rs 3/per KL • Bore well Rs 15-18 / kl • Cauvery iv stage Rs 48 per KL

The monitoring.. • Each connection is metered • Each bore well pays Rs 50 /- a month as sanitary cess . Can bore wells be metered and volumetrically priced? • Will people manage groundwater better if it is cheaper than piped supply?

The construct of the problem determines the solution • Mulbagal town : 70,000 population • Arghyam initiative for IUWM • Grey area according to the CGWB • Mines and Geology suggests 600 feet as g.w. depth • Studies indicate g.w. at 20 feet depthBGL in a well defined shallow aquifer enough for Mulbagal’s needs

Energy cost • Approx 60 % of the muncipality’s budget goes for energy charges towards pumping costs annually

Sustainability • Socially- • Technically • Institutionally- Where are the urban gwi’s? • Legally- Where is the law? • Economically- What is the incentive? • Ecologically- How do we protect aquifers and base flows?

The Importance Of Groundwater In Urban India: S. Vishwanath

by India Water Portal on Jun 03, 2009

Accessibility

Categories

Upload Details

Usage Rights

1 Embed 8

Statistics

The Importance Of Groundwater In Urban India: S. Vishwanath — Presentation Transcript