GROUNDWATER GOVERNANCE Priorities to Sustain a Critical Resource Prof Dr Stephen Foster Global Water...

GROUNDWATER GOVERNANCE Priorities to

Sustain a Critical Resource

Prof Dr Stephen FosterGlobal Water Partnership–Senior Adviser

International Association of Hydogeologists–Past President

GLOBAL WATER PARTNERSHIP

FAO-UN Investment Days 2014

Global WaterPartnership

GROUNDWATER – A GLOBAL OVERVIEW • Strategic Importance & Sustainability Concerns

• Intimate Relation with Irrigated Agriculture • Strengthening Groundwater Governance• Specific & Urgent Investment Priorities

GROUNDWATER – NATURAL DISCHARGE fundamental role in sustaining aquatic ecosystems

FRESHWATER DISCHARGE TO COASTAL

LAGOONS

NATURAL BASEFLOW TO RIVER ECOSYSTEMS

• groundwater – the ‘traditional role’ source of >50% (rural/urban) drinking water-supply

REGIONGROUNDWATER

IRRIGATION AREA Mha total

GROUNDWATER VOLUME USED

km3/a propn

GLOBAL TOTAL 112.9 38% 545 43%

South Asia(India/Pakistan)

48.3 57% 262 57%

East Asia (China) 19.3 29% 57 34%

South-East Asia 1.0 5% 3 6%

Mid-East & North Africa

12.9 43% 87 44%

Latin America 2.5 18% 8 19%

Sub-Saharan Africa 0.4 6% 2 7%

GROUNDWATER IRRIGATION USE

the global boom

• groundwater extraction increased 300% in 50 years (1960-2010)

• massive growth of irrigation waterwells in some regions facilitated by government (energy subsidies/construction loans/crop guarantees)

(Siebert et al, 2010 for FAO-UN)

GROUNDWATER DEPLETION – NEGATIVE EXTERNALITIES onset and impact varies widely with aquifer type

• energy consumption• carbon footprint

• contribution sea-level rise

GROUNDWATER DEVELOPMENT STAGES environmental and socio-economic impacts

GROUNDWATER RESOURCE DEPLETION a widespread and accelerating phenomenon

Konikow, 2011

• ~15% of existing staple grain

irrigated with non-renewable groundwater resources• mining of fossil

groundwater during 1955-2005 contributed 10-15 mm to sea-level rise

IRRIGATED AGRICULTURE & GROUNDWATER RESOURCES an intimate multi-facetted relationship

• irrigated land-use practices are a major influence on groundwater recharge

• groundwater salinisation is a serious and complex threat associated with irrigated agriculture in more arid climates

• groundwater very popular with farmers (self control/direct local access/drought secure)

irrigated agriculture is the major consumer of groundwater resources

• agricultural land-use is a ‘leaky activity’ and a major source of diffuse groundwater pollution

• scientific tools now available to characterise the dynamics of these interactions with confidence and in

detail

SURFACE-WATER IRRIGATION MANAGEMENT effect on groundwater recharge rates and quality

permeable soil profiles

quality cannot be divorced from

quantity

PERU-ICA VALLEY : ASPARAGUS PRODUCTION sustainability threatened by decreasing recharge

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• relatively stable groundwater abstraction over past 50 years

• recent falling water-table due to

abandoning spate/flood irrigation

• modernisation of irrigated cropping

with increasing consumptive use –

urgently needs supporting by managed recharge measures

PAKISTAN PUNJABgrowing groundwater dependence for staple crop production

but continuing long-run battle with the ‘salinity dragon’

arid zone with fresh groundwater recharge primarily from riverbed and irrigation canal seepage – but freshwater salinity increasing

due to salt fractionation in irrigated soils, extensive phreatic evaporation and use of deep irrigation waterwells

semi-arid zone with diffuse groundwater recharge

from annual monsoonal rainfall

GROUNDWATER SYSTEM SALINISATION factors entering into aquifer salt balances in arid

areasfreshwaterrecharge

return watersvarying salinity

other factors in aquifer salt balances :• drawing-in from phreatic and

vadose zone salinity • mobilisation via deep waterwells

• inflow from saline formations

mmm

DIFFUSE POLLUTION FROM

AGRICULTURAL LAND-USE

nutrient leaching

pesticide mobility

Cryptosporidium hazard

saline returns

cultivation of permeable soils is a ‘leaky activity’ – farmers cultivating land also (accidentally) harvest

groundwater

historically groundwater resources have largely been ‘abandoned to chance’ in face of agricultural

development ‘business-as-usual’ will result in further irreversible degradation and growing conflict

government role must transform from ‘promoter of short-term development’ to ‘long-term resource guardian’

widespread need to strengthen governance provisions : building effective institutions creating an adequate base making essential linkages aligning financial incentives implementing management plans

promote more integrated and sustainable policy with appropriate monitoring and assessment as basis for adaptive management to cope with global change

GROUNDWATER GOVERNANCE & MANAGEMENT

size matters – understand context

evident governance provisions/ management approaches must to a degree be context

specific and take account of :

HYDROGEOLOGICAL SETTING• Groundwater Resource

Renewability• Susceptibility to Degradation

• Scale of Aquifer Storage • Connectivity with Surface Water

POLITICAL ECONOMY OF RESOURCE • Propn of Population Using

Waterwells• Number of Abstraction Points

• Economic Significance of Resource Use

• Capacity of Water Resources Agency

‘one size cannot fit all’ Groundwater Resource Management

TAILOR TO CONTEXT

CONJUNCTIVE USE FOR IRRIGATED AGRICULTUREmanaged evolution from spontaneous to planned development

SPONTANEOUS PLANNED

waterlogging & salinization risk if

water-table shallow

groundwaterdepletion risk

GROUNDWATER & IMPROVED IRRIGATION TECHNOLOGY ‘irrigation-water efficiency’ a misleading term

• ‘irrigation-water efficiency’ improved 40% to 80% (230 mm for wheat crop)

• but ‘real water-resource savings’ (reductions in non-beneficial evaporation)

only by 55 mm for crop (< 40 mm/a over entire land area) • most so-called ‘water losses’ were in fact irrigation returns to

groundwater

• modifying monsoon rice cultivation in Indian Punjab more successful –

delayed-planting generated reduction in non-beneficial evaporation of 90-100 mm/a for rice crop (80-90 mm/a over entire land area)

DEMAND MANAGEMENT• align fiscal incentives in support of resource sustainability (construction grants, electricity subsidies, crop guarantee prices)

• regulate waterwell extraction and consumptive use (‘smarter approaches’ to controlling waterwell use) (focus on reduction of non-beneficial evapotranspiration) (innovative use of financial nexus with energy

provision/charging)

SUPPLY ENHANCEMENT reward land stewardship that augments recharge promote productive land-use that protects groundwater

quality

INSTITUTIONAL FOUNDATION• strengthen government agency capacity to administer

resource• integrate responsibility for resource conservation

and quality protection • establish essential linkages with dependent

sectors/activities nuture stakeholder participation via financial

and regulatory support improve groundwater system and soil-water accounting (including groundwater level/quality status monitoring –

with telemetry to provide basis for adaptive management)

• finance revenue cost of monitoring (from selective levying of a resource fee)

promote and optimise conjunctive use with canal-water in alluvial systems (understanding physical connectivity and overcoming socioeconomic impediments)

GROUNDWATER GOVERNANCE

Priorities to Sustain a Critical Resource Prof Dr Stephen Foster

Global Water Partnership–Senior Adviser

International Association of Hydogeologists–Past President

GLOBAL WATER PARTNERSHIP

FAO-UN Investment Days 2014

Global WaterPartnership

GROUNDWATER GOVERNANCE Priorities to Sustain a Critical Resource Prof Dr Stephen Foster Global Water...

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