CONJUNCTIVE USE PLANNING IN A CANAL COMMAND FOR FOOD SECURITY COMMAND FOR FOOD SECURITY

Presented byPresented by

DEEPAK KHAREProfessor

Department of Water Resources Development & ManagementDepartment of Water Resources Development & ManagementIndian Institute of Technology RoorkeeIndian Institute of Technology Roorkee1

INTRODUCTION: WATER SECURITY?

ANNUAL RAINFALLMin. = 100 mm : Western Desert Max. =11000 mm : North-Eastern RegionAvg. =1170 mm : All India

WATER RESOURCES ON INDIA (In BCM)WATER RESOURCES ON INDIA (In BCM) Total Precipitation : 4000 Total Water Availability : 1869 Total Utilisable WaterTotal Utilisable Water

– Surface Water - 690– Ground Water - 433 = 1123

CAN INDIA ENSURE WATER SECURITY?India has only 2.4% of the world’s total land area (328 Mha)16% of the world’s populationp p4% of the total available fresh water Per capita water availability is expected to decrease to 662 m3 by 2050

INTRODUCTION: FOOD SECURITY?

Agriculture plays a key role in over all economic and social well being.

Share of agriculture in GDP: 39% (1983) – 24% (2000-01) Sh f A i i l t 63% (1983) 57% (2000 01) Share of Agri. in employment: 63% (1983) – 57% (2000-01) Avg. food consumption at present: 550 gm per capita per day Area under food grain: 126.67 Mha (1980) – 124.24 Mha

(2003) Food grain production: 129.59 Mt (1980) – 212 Mt (2003)

Projected population in the year 2020: 1.30 billion Food requirement by the year 2020: 300 Mt Food requirement by the year 2020: 300 Mt

Our Farmer’s need to produce 50% more grain by 2020

WITH THE FOLLOWING CONSTRAINTS∆ Climate change - unpredictable rainfall &

temperature∆ Growing population

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g p p∆ Labour (disheartened youth)∆ Policy (world & nation)

Water facts and figures (Food security & Agriculture)

Water facts and figures (Food security & Agriculture)

Projected global population growth= 2–3 billion over the next 40 years

Projected global food requirement = Present demand + 50% by 2030, = Present demand + 70% by 2050= Present demand + 70% by 2050

This demands huge requirement of freshwater to sustain agriculture!!!g

Agriculture accounts ~70% ofglobal freshwater withdrawals. Agricultural water consumption isestimated to increase by ~19% by 2050.y y

Source: FAO

CAN INDIA AFFORD WATER SECURITY?

Land – Available fresh water – Population (A skewed square ratio))

Land = approx. 2% of the world’s total land area Water = approx. 4% of the total available fresh water Population = approx. 16% of the world’s population

Population – Food requirement (An up-hill task)

Projected population in the year 2020 = 1.30 billion Food requirement by the year 2020 = 300 Mt Our Farmer’s need to produce 50% more grain by 2020 to meet Our Farmer s need to produce 50% more grain by 2020 to meet

the requirement

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Key Issues and Challenges (Indian context)E i t il bilit f ll t k h ldEnsuring water availability for all stakeholders

Drinking water Agriculture (for food security); Irrigation efficiency Corporate demand Corporate demand Municipal use Domestic use

Managing extreme climatic eventsDrought Drought

Flood

Conservation, management, distribution & utilization

Climate change

Conservation, management, distribution & utilization Major, medium & minor schemes (watershed management &

RWH) Fund

Conflicts

u d Manpower; Infrastructure

International & National

Flood

River linking Policy and regulations Trade (Virtual water)

ISSUES IN A CANAL IRRIGATION SYSTEM

Reduced Water Use Efficiency (WUE) approx. 38-40 % at present

The major issues pertained to a Canal Command are :

(GOI, 1999 Vol. II: 482).Intensive irrigation increased water logging, salinity, making the soilunproductive.Poor drainage resulting to waterlogging in the Indian subcontinent.Irrigation service delivery were usually erratic and inequity between the headsand tail ends of the canals resulting in poor yields.Cumulative seepage of canal water tends to raise groundwater to the crop rootzone.Groundwater recharge from canal seepage depends upon the size and the

ti f th l d th f fl h t i ti f il i th b d dcross section of the canal ,depth of flow, characteristics of soils in the bed andsides.Distribution losses from the canal command system generally consist of theevaporation losses and seepageevaporation losses and seepage.Overexploitation of groundwater resluts in decline of water levels

Intensive Irrigation in canal commands :Intensive Irrigation in canal commands :-water logging salinity,

ki h il d imaking the soil unproductiveWater Scarcity for agriculture :-

Overexploitation of groundwaterOverexploitation of groundwaterLowering of water levels Causing decline in yield and productivity of wells, S t i t i l th tSeawater intrusion along the coast, Drying of spring and shallow dugwells,

Increase in cost of lifting According to Todd (1980) “Future demand for water requires planning the

maximum utilisation of all existing supplies. This can most economically be

obtained by Conjunctive use of surface water and ground water reservoirs.”

CONJUNCTIVE USE: WHAT DOES IT MEAN?

Conjunctive use of water refers to optimal allocation of groundwater

India can tackle food &water security along with the associated issues in a canal command through ‘Conjunctive Use of Water’ .

Conjunctive use of water refers to optimal allocation of groundwateralong with surface water in any irrigation system (FAO).

Mixed for productive use

SURFACE WATER GROUNDWATERuse

M t f f t d d t iManagement of surface water and groundwater resources in acoordinated manner such that the total yield of such a system over aperiod of years exceeds the sum of the yields of the separatecomponents of the system resulting from an uncoordinated operationcomponents of the system resulting from an uncoordinated operation(Coe, 1990).

CONJUNCTIVE USE: WHY?

Obvious solution is to storePrecipitation Obvious solution is to store surface water behind reservoir, aquifer storage ( d t ) ill dd

Precipitation(Rainfall, snow)

Peak Runoff in a season (groundwater) will add value since….Usually coincides with

low water demand period Surface storage drawslow water demand period

Requirement of water transfer

Surface storage drawsfollowing bottlenecks

High evaporationH di itransfer

from high supply season to high demand season

Huge sedimentationSocio-environmental impactsExpensive for distributionpfrom dam to utility area

SURFACE WATER AND GROUNDWATER INTERACTION: HOW?INTERACTION: HOW?

Groundwater is linked to Surface Water by:• Ground Water - Recharge from rivers, Lakes, wetlands & seawater• Surface Water - Recharge from springs, seeps & subterranean flow

Recharge to Surface water Recharge to Groundwater

SURFACE WATER AND GROUNDWATER INTERACTION HOW? Hydrologic Cycle explains the origin ofgroundwater and the occurrence and

f i h h h

INTERACTION: HOW? Contd…

movement of water in the earth-atmospheresystem as well.

Water enters the GW system at recharge areas.y gWater leaves GW system at discharge areas.

Movement of Water

Atmosphere to surface: PrecipitationSurface to atmosphere: EvaporationRelease of water by plants : Transpiration

On surface: down slope movement to lakes,streams, and oceans

Below surface: movement of groundwater

SURFACE WATER AND GROUNDWATER INTERACTION HOW?

RAINFALL SURFACE WATER SYSTEM

INTERACTION: HOW? Contd…

RAINFALL SURFACE WATER SYSTEM

Seepage

Evapotranspiration Surface Water releases

LAND USE SYSTEM

RAINFALLRECHARGE

p gfromconveyanceSystem

AQUIFER

Groundwater withdrawals

Seepage from conveyance system

AQUIFEREffluent or influent seepage

Fig. Block Diagram Illustrating Conjunctive Use of Surface Water And Groundwater (Roger And Smith, 1970)

OBJECTIVES IN CONJUNCTIVE WATER USE

Improved availability and dependability of water supplyp y p y pp y

Reduce water logging and salinity.(Environmental)

Improve production, equity and poverty alleviation. Improve production, equity and poverty alleviation.

Optimize expenditure on rehabilitation.(Fiscal)

State disengagement from canal irrigation management State disengagement from canal irrigation management.

Utilize underground storage and improve accessibilityand overall water use efficiencyy

ADVANTAGES OF CONJUNCTIVE WATER USE1. Use of groundwater helps to reduce peak demands for irrigation,

size of canals and hence construction cost.

2 Supplies from groundwater ensure proper irrigation scheduling2. Supplies from groundwater ensure proper irrigation scheduling,raising multiple crops and early sowing even if rainfall is delayed.

3. Increased water supply to tail end areas thereby improving equityand reliability.

4. Groundwater exploitation lowers the water table and reducesdanger of water logging and consequent wastage of water.g gg g q g

5. Surface and sub-surface outflows are minimized, causing reductionin peak runoff and flood discharge.

6. Increase in overall efficiency of the system due to recycling ofirrigation water.

7. Need for canal lining is reduced as seepage from canals rechargesg p g ggroundwater.

CONSTRAINTS IN IMPLEMENTING CONJUNCTIVE USE PROGRAMMES

1 Possibilities of deterioration in groundwater quality due to influx of1. Possibilities of deterioration in groundwater quality due to influx ofsalts leached down from soil, which may be quite marked as a result ofrecycling within zones of depressions and or upland and lateral migrationof saline water into fresh water zones in response to pumping.p p p g

2. Increased power consumption to sustain pumpage from well,possible dislocation of groundwater supplies due to power failure incritical periods and decrease in pump efficiency due to large fluctuationscritical periods, and decrease in pump efficiency due to large fluctuations.

3. Operation, supervision and control of conjunctive use and artificialrecharge projects are more complex.

4. Administrative difficulties in evolving acceptable and equitable waterrates, providing motivation and incentives to accept groundwater usewhen surface water is available.

ELEMENTS OF CONJUNCTIVE WATER USE

Conjunctive use requires physical facilities forj q p y

1. Water distribution2 Artificial recharge2. Artificial recharge3. Pumping of groundwater

Based on the above discussions, three importantcomponents of the conjunctive use planning are:

1. Surface water supply and its conveyance2. Groundwater supply and withdrawal3 N t f i lt l l d3. Nature of agricultural lands

Water Management: Supply sideWater Management: Supply side

• Abundant supply of freshwater• Abundant supply of freshwater• No signs of surface water reduction yet

ButBut• Increasing risk of pollution• Uncontrolled groundwater abstraction• Potential risk of recharge reduction

Water Management: Demand sideWater Management: Demand side

• Lack of awareness on water issues• Lack of awareness on water issues– One of the least developed regions– Lack of adequate infrastructureLack of adequate infrastructure

• Increasing demand for fresh water– Increasing population– Increasing urbanization– Intensification of agriculture

Case StudyCase Study

Ch i C i P tt t• Change in Cropping Pattern.pptx• Tawa-Canal Conditions.pptx• Water Logging Tawa Canal.pptxLower

Ganga Canal System.pptxg y pp

Water Management Options :Basis for Consensus

• A basin wide management approach• A basin-wide management approach• A surface water-groundwater conjunctive development,

use, and management, g• A regional development policy and water-use strategy• Effective involvement of all stakeholders• Balancing water quality and quantity

CHALLENGE OF CONJUNCTIVE USE OF GROUNDWATER & SURFACE WATER RESOURCESWATER RESOURCES

• Study of Canal System with time and try to incorporate the• Study of Canal System with time and try to incorporate thepossible impact– * Sections of Canal---M & R Issues

* C i P t– * Cropping Patern– * Level of Irrigation

• Understand Level of Irrigation and corresponding Yield

• Integrated modelling for tropical climates often demonstratesIntegrated modelling for tropical climates often demonstratesthat cropping intensity for entire command area could beincreased with ‘planned conjunctive use’ and better crop choicescould further enhance ‘irrigation water productivity’g p y

CHALLENGE OF CONJUNCTIVE USE OF GROUNDWATER & SURFACE

• But how to overcome social and economic obstacles toi li i j i ( li i l f h d l l d

WATER RESOURCES

rationalising conjunctive use (political power of head-canal landowners, comparative water cost to users and initial capitalinvestment requirements) ?

• Need very widely to move from ‘opportunistic water engineeringand agricultural development to integrated land and water

t i l di f ll id ti f d t ‘management including full consideration of groundwater ‘

• In our overall long-term interest and especially so facing theneed to adapt to accelerated climate change withmanaging/reducing the problems of water-logging,salinity and scanty supply in tail end regions of anysalinity and scanty supply in tail end regions of anycanal command

Thank You!