July 10-11, 2017UNESCO-IHP Regional Workshop, Langkawi

Dr Aftab Ahmad

Over one million Sq. kilometre area

Covers 14% of country’s area over 5 states

20 major rivers

Only 6% of annual rainfall (165mm/year)

40% of country’s agricultural production

70% comes from irrigation

Salinity and Drainage Strategy (1989) In the mid-1980s more that 96,000 hectares of irrigated land

in the Basin were showing visible signs of salinisation It was estimated that the irrigation areas affected by high

water tables could increase from 559,000 hectares in 1985 to 869,000 hectares in 2015

increase in river salinity largely due to contributions from an increase in groundwater mounds under irrigation areas,

and surface and sub-surface drainage from the high water table areas

Each State responsible for actions significantly affecting river salinity taken within its jurisdiction

Introduction of salinity register to maintain salinity credits/debits

Cap (1997) Limit on the volume of water that could be diverted from the rivers in the

basin for consumptive use (mainly irrigation) from 1997 after realizing that ongoing increase in consumptive use of water in the Murray-Darling Basin (MDB) was environmentally and socially unsustainable.

This limit is called the cap and effectively limits the volume of water diversions to 1993/94 development level.

No additional water could be diverted from the river for new developments. Positive outcomes:

▪ River health, ▪ impetus for water saving by improvement in water use efficiency, and water trading. ▪ The improvement in irrigation efficiency helped control rising watertable in

inefficiently irrigated areas▪ Made water available for new irrigation developments and ▪ Water trading provided a market mechanism to temporarily shift water from low value

to high value use.

Discrepancies in Cap implementation and monitoring

National Water Initiative (2004) Agreed in 2004

Under NWI, governments have made commitments to:▪ prepare comprehensive water plans

▪ achieve sustainable water use in over-allocated or stressed water systems

▪ introduce registers of water rights and standards for water accounting

▪ expand trade in water rights

▪ better manage urban water demands.

Water Act 2007 (2007) 10 year 10 billion water for future program

Federal government given more regulatory power to reform the Murray-Darling basin.

Water charge and water market rules functions given to the Australian Competition and Consumer Commission.

Functions in relation to water information given to the Bureau of Meteorology.

Established Murray-Darling Basin Authority.▪ Responsible for overseeing water resource planning in the

Basin

▪ Basin Plan

Water Act 2007 (2007) cont’d...

Basin plan

▪ Sustainable diversions limit

▪ Buyback

▪ Supply measures

▪ Efficiency measures

Water Trading

▪ Improved market mechanism and transparency

Established the Commonwealth Environmental Water Holder

▪ Manages Commonwealth’s environmental water portfolio.

Water is a tradable commodity and has an economic value One of the driving factors behind the trend for water use

efficiency improvement Institutional reforms:

creating water markets and regulatory framework decoupling water and land property rights, and allowing water to flow from low value uses to high value use

with minimum of transaction costs Water trade price has been as high as $1,062/ML during

drought periods. The average water trade price from 2005-06 to 2010-11 in

MIA: $271/ML Tradeoffs between water trading and environmental and

equity goals

Murrumbidgee Irrigation Area Total irrigated area: 3,624 sq. km Total surface water use for irrigation: 1,250 GL 8% of the area is covered by horticultural crops Average rainfall: 530 mm/year Average potential evapotranspiration is 1000 mm/year

Murrumbidgee Irrigation Area Over 3500 km of irrigation supply channels Only 250 km are lined and 100 km are piped Seepage loss as high as 20 mm/day

Shift in irrigation systems in MIA (% of total irrigated area)

17.2

52.9

23.2

0.9 0.3 3.5 2.0

DripFloodFurrowLow headMicrojetSprinklerOverhead

0.7

91.2

0.25.6

2.3

drip/subsurface/trickle

surface

fixed overhead sprinklertravelling irrigator

moveable spray

2003

2009

An unintended consequence of technology adoption to achieve improved water use efficiency is the significant increase in energy use and energy cost and its long-term impacts on climate change

Energy input in agriculture is directly related to the level of technology adoption and the level of production.

Optimisation of water savings and energy consumption

Energy used

Water saved

N2

N3

N4 N5 N6

N7

N8

N9

N10 N11 N12 N13

WaterSource

N1a

N7a

(273) (552)(291)

(102)

(446) (150)

(368)

(100)

(585)

(508)

(271)

(324) (4) (94)

Schematic of 13 farm nodes and supply link

Scenario 1: Furrow –gravity

Scenario 2: Sprinkler with pressurised irrigation

Scenario 3: Drip with pressurised irrigation

Ph1

PumpEfficiency

N2

N3

N4

N5

N6

N7

N8

N9

N10 N11 N12N13

ETc_adj_3

ETc_adj_4

ETc_adj_5

ETc_adj_6

ETc_adj_7

ETc_adj_8

ETc_adj_9

ETc_adj_10

ETc_adj_11

ETc_adj_12

ETc_adj_13

TotalDynamic

Head

ReservoirN1

Total_DutyFlow_Rate

TotalPumpPower

PumpDischarge

No._of_Pumps

O3vel

O4vel

O5vel

O6vel

O7vel

O8vel

O9vel

O10velO11vel O12vel

O13vel

Rn1

Rn2

Rn3

Rn4

Rn5

Rn6

Rn7

Rn8

Rn9

Rn10

Rn11 Rn12

Rn13

f1

f2

f3

f4

f5

f6

f7

f8

f9

f10

f11f12

f13

Hf1

Hf2

Hf3

Hf4

Hf5

Hf6

Hf7

Hf8

Hf9

Hf10

Hf11

Hf12 Hf13

Ph2H2

Ph3H3

H4Ph4

H5Ph5

H6Ph6

H7

Ph7

H8

Ph8

H9

Ph9

H10

Ph10H11

Ph11

H12

Ph12

H13

Ph13

H1

N1a

ETc_adj_1a

O1avel

Ph1a

Hf1a

f1a

Rn1a

H1a

N7a

ETc_adj_7a

Hf7a

f7aPh7a

Rn7a

O7avel

H7a

CumulativeEnergy_Use

CumulativeIrrigation_Volume

I1a

I10

I11

I12

I13

I3

I4

I5

I6

I7

I7a

I8

I9

RZ_depletion

1a

BrakePower

Motor_Efficiency

Total_Dynamic_Head

200

150

100

50

0

1 53 105 157 209 261 313 365

Time (Day)

Total_Dynamic_Head : WithIrrRateDrip m

RZ_depletion_6

Ks_6

RZ_depletion_3

RZ_depletion_7

RZ_depletion_8

RZ_depletion10

RZ_depletion11

ETc6

RZ_depletion_5

Ks_5

ETc1a Ks_1a

ks_3ETc3

RZ_depletion12Ks_12

ETc12RZ_depletion

13Ks_13

ETc13

Ks_7ETc7

ETc8

ETc5

Ks_10

ETc10 Ks_11

ETc11

RZ_depletion_4

Ks_4ETc4

RZ_depletion7a

Ks_7aETc7a

RZ_depletion_9

Ks_9

ETc9

Ks_8

RZD_6

DP_6

RZD_5

RZD_4

RZD_3

RZD_1a

RZD_7

RZD_7a

RZD_8

RZD_9

RZD_10

RZD_11

RZD_12

RZD_13

DP_5

DP_1a

DP_12

DP_13

DP_3

DP_7

DP_10

DP_11

DP_4

DP_7a

DP_8

DP_9

Ev6

Ev5

Ev1a

Ev3

Ev7

Ev10

Ev11

Ev4

Ev7a

Ev8

Ev9

Ev12

Ev13

Cum_evap_lossCum_DP_loss

Water_Availability Water_Trade_Price

Investment_on_WaterSaving_Irrigation

-

+

Irrigation_WaterSavings

+

+ Water_savings

per_$_invested

Climate_change

Climate_shift

Change_in

policy_settings

+

-

Irrigation_WaterSavings

+

+ Water_savings

per_$_invested

PumpingEnergy_Use

GHGEmissions_Tax

Net_Returnfrom_Saved

Water

+

+

-

- Energy_use_per

ML_savings

Emissions_per

KWh_energy_use

0

2

4

6

8

10

12

1 2 3

Irri

ga

tio

n R

ate

(M

L/h

a)

Scenario

Citrus

Stone fruit

Wine grapes

Scenario 1: Furrow – gravity (labour intensive)

Scenario 2: Sprinkler with pressurised irrigation

Scenario 3: Drip with pressurised irrigation

0

2,000

4,000

6,000

8,000

10,000

1 2 3

En

erg

y U

se (

kW

h/h

a)

Scenario

Citrus

Stone fruit

Wine grapes

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

200,000

20 30 40 50 60 70 80 90 100

Wat

er u

se (M

L) &

En

erg

y u

se (M

Wh

)

Percent of MIA horticultural area covered (%)

Total water use - drip (ML) Total water use - sprinkler (ML)

Total energy use - drip (MWh) Total energy use - sprinkler (MWh)

Adaptive management and policy responses to address the evolving water challenges.

Both water and energy have implications on sustainable development of agricultural production systems.

Water and energy use are strongly interlinked in irrigated systems.

Irrigation efficiency should be considered at system scale incorporating technical, economic & environmental aspects.

Need for finding an optimum level of adoption and appropriate mix of technology.

For further information:

Email: aftab0707@gmail.com