Sustainable use of groundwater for smallscale irrigation

Sustainable use of groundwater for smallscale irrigation

Lcrmf L’w Prhc.y I’wl I I I-1) 27.~35 Sustainable use of groundwater for smallscale irrigation With special reference to subSaharan Africa Richard ...

1MB Sizes 7 Downloads 269 Views

Lcrmf L’w Prhc.y I’wl

I I I-1) 27.~35

Sustainable use of groundwater for smallscale irrigation With special reference to subSaharan Africa

Richard C Carter and Peter Howsam

Concepts of sustainability are discussed In relation to small-scale groundwater irrigation (SSGWI). The nature and important features of SSGWI are described, and the main endogenous and exogenous threats to the sustalnabillty of thls important farming activity are set out. The Importance of groundwater monltorlng and management, together with effective leglslatlon and control, are hlghllghted. The potential conflict between promoters of rapld groundwater development for poverty alleviation and the proponents of a more cautious approach Is discussed. The ‘Invisiblllty’ and limited area of SSGWI In semi-arid, sub-Saharan Africa are contrasted with their importance in what are otherwlse drought-prone dryland environments. The aulhors are with the Water Management Department, Silsoe College, Cranfield University, Silsoe. Bedford, MK4.5 4DT. UK. ‘Barghouti. S. and Le Moigne. G /rrigafion in Sub-Saharan Africa: The Developmenl of Public and P&ale Sysfems Technical Paper No 123. World Bank, Washington, DC (1990); Brown, E P, and Nooter. R Successlul Small-Scale Irrigation in the Sahel Technical Paper No 171. World Bank, Washington, DC (1992); Carter, R C (ed) NGO Casebook on Small Scale Irrigaf/on in Africa AGL/MISC/l5/89. FAO. Rome (1989); Serrano. V M B L. and continued on page 276

SIII;III-SC;IIL’

irrig;ttion

Ixo~litclioii

ill inany

~u;~tlc it invisible cxisling

SSI

potcnti;il

is supplictl

for

the

strcngthcn

their

to lhc

hits

ccrtitinly

viillcy

region’s

ilgfiCUltUrill

The

focus

this

Icssons

threats

of

much

of

it is wiclcly

irrigation

intlircctly.

to

thcsc

of

threats

r~gildlCss

this

arc due

Of its

Wiltcr

to the use of gIX~lll1dWiltCr.

sul~-Silhi~riln

Africn’s

Although

bclicvcd

itgriculturill

irrigation

that

sn~illl-scitlc

may have ;I significilnt

pilrt

in gcncrill

is

irrigation

in

to play

in the

future.’

of sn~i~ll-scillc ilnillysis

of the ittlitlysis

h;is

;i sigiiil’icaiit

;ind,

of

irrigatiOI1

rclatc

rccognizcd.

been

bottomlands

;Irc drawn

I’ood Much

to the sust;Gnability Soiil~

of this paper is to analyst

purpose

susti~inilbility

is still

grountlwatcr

f;irmcrs,

activity.

Of Sll1~~ll~SCillC

no panacea.

Africa’s

scvcral

specifically

state long

govcrnmcnts.

tlwrc

anti

to tlcvclop

siii;ill

of

farming

tliltllrl‘

parlous

‘I’hc ccon~~~~y

exist

others

while

African

to

howcvcr,

ccononiics.2

procluctivc

i1lf~orlllill

source.

bcncfil

contril~iition

Its iiil’orni;tlity,

by, many

of the world

nation;il thcrc

and

;I signil’iunt

couiilrics.’

by grountlw;itcr.

parts clircct

Ncvcrthclcss valu;tblc

iii;~lics

IO. antI ignorctl

iii many

further

(SSI) tlcvclol3iiig

pilrticulilrly from

the issues

groundwater

both

OII sub-Sahilriln

Asia

south

dctcrrninc

in gcncrill,

Africa.

and Africn.

iit Africa

;lrc titrgctccl

which

irrigation

Expcricncc

but the policy

the

and to ilnd

implications

of the Sith:Iril.

Definitions and concepts The

first

‘Slllilll-SCillC

meanings. them.

and

third

tcrrns

irrigation’)

It is important

in the

carry

a

title witlc,

to set out

of

this

paper

illld often

what

(‘sustilini~blc’

ill-&find.

the prcscnt

authors

ilnd

range

of

mean

by

Small-scale quite

irrigtition

distinct

irrigated

area.

in total refers

is an unfortunate

meaning>.

size

(usually

is

SSI

from

ovt2r:Ill The

of

from page 275

Groundwaler Irrigation and the Rural Poor: Options for Devefopmenl in Ihe Gang&c Basin World Bank, Washington, DC (1993)

‘Carter. R C ‘Small scale irrigation in subSaharan Africa: a balanced view’ in Proceedrngs of the Conference on Priorilies for Waler Resources Allocation and Management, Overseas Development Adminlslralion. Southampton. UK (July 1992); Dlemer. G, and Huibers. F P FarmerManaged lrrigalron in the Senegal River Valley: tmpfications for fhe Currenf Design Method End-of-project report, Waler Man-

agement Project. St LouisIWageningen. WARDA/Wageningen Agricultural University (1991); UnderhIll op cif Ref 1; Van Sleekelenburg. P N G, and Zijlstra. G Evaluation of frrrgalron Projecls Sponsored by the European Economic Communify:

Synlhes/s Report International lnstrtule for Land Reclamalion and Improvement. Wageningen. Ihe Netherlands (1985) ‘FAO Consultalion on lrrigalron In Alrica Irrigation and Drainage Paper No 42, FAO. Rome (1987) 5Newslefler No 1 of the informal Working Group on Small Scale Irrigalion. June 1988

csploits

systcni’ InsIitutc

shoul~l

almost

waIcr.

olhcr

grounilw;ilcr v:iricty

cniphasizcs,

irrig;kIion

of

in

sub-irrigation

of up to

govcrnnicnt

or

Ciroup

intlucncc,

plots,

antl

cffcctivcly

ol>cr:IIc

anrl

the

;IS uscrl

(I IMI)

;1nl1 others.

;I

2nd firstI)

thirtlly

rather

(f:MfS).

in

using

of inil~~W;Incc,

Icchnology, from

on Sm;~ll

on sni:Ill

l>hysical

hctlcr

term.

by the InIcrri;IlionII is Ihis

concept

paper. not bc rc;Irl

ant1 niotlcrn

any f;Irniing

than

the

usually

in or&r

managcahlc

of tr:Iclition;Il

Gencrirrigation

or tenancies

Working

c;in

ilidistiligiiish;~I,lc

‘irrigirlion’

the

sc;~lc.

or private

of

controlling

farnicrs

in the prcscnt

in Africa,

hancls

irrig;Ition.

the

M~~nagcmcnt

-f‘hc tcrni

‘.

which

;I

in

the project.

the major

irrigation

of the tlivckty

the

aspect

and plot size m;~y be small.

prop~>sccl by the UK

sccontlly

is xlo~~tcd

in

initiatecl

have

is thcrcforc

scheme

I to

Although

irrig:ktion’.

have holclings

to

small

the FAO

is physical

to public

tuo

‘typically

primary

‘smallholder

to refer

usually

.1.his tlcfinilion

;II Irrigation

fount1

is which

of SSI

control.

which

is taken

the

is taken

the term

is ;IS follows:

‘f;Irriicr-n1;11i~I~~~l Carter. R C ‘Small scale rrngallon In Angola: polenlial and promrse’ Ouflook on Agrtcutlure 1991 20 (3) 175-181; UnderhIll, H W Small Scale frrigalron m the Conlexl of Rural Devetopmenl Cranheld Press, Bedford, UK (1990) ‘Carter. R C ‘Groundwaler development for small scale rrrigallon in sub-Saharan Africa’ paper delivered lo Hydrogeologrcal Group Meetmg of Geological Society of London, ‘Groundwaler and irrigation’ (April 1989); Kahnerl. F. and Levine, G (eds)

definition

farmers

technology

sck~lc. SSI

control.

although

farmers

nI;iintain’.i f;Irnicr

conllnued

about

indiviclual

agency

smnll

I~vcl

f3rmers’.

In this C;W,

Irrigation

N hich

or single

irrigation

dcfinitivn

Sc;rlc

Thus

groups

ni:Inagcnient

commercial

in hectares).

by farmers’ here

on

to refer

art’ literally

;IS those

this

in ivhich

to ;Irt’;l

which

in Africa

with

;I few hectares.

has taken is taken

schemes

which

schcmcs

or projects

to refer

has been confusccl

ally sniallholcfcr

uhich

the term

irrigation

included

classification

schemes

taken

1IH) ha, controlled

term

its face v;dut’

perimeters.

to small-scale

comment

At

too n:irrowly. water

practice

tlircct

r:Iinfall,

the

conlcxt

pr;icticcs,

In the context pr;Icticcs

lll~llliI~ClllCllt

which

conscrvcs,

tlirccts

can bc seen as irrig;ltion. of

this

;IS well

paper

must

;IS niorc

or

‘I’hus

inclutlc

;I

convcntiomrl

lift

irrigation. SSI

shoulcl

not hc pcrccivccl

its practitioners.

The

izctl by clivcrsity

antl multiplicity

SSf

rur:Il

is but one option

risks

ant1 gcncrate

The

rclcvancc

managed both

Scconcl. is the

farmers

ncccssary

themselves

to which

technology.

Unlike

irrigation

schcnics. (including

concept

of sustainability survival,

rcsponsihility

tenacity

:lfford,

f:irnicrs

technology

cntfurancc.

(internal)

fnrmcrcontrol

of

vulncrublc threats.

towarcls ‘schcmcs’;

to

On

the

the activiancl on the

to manage

their

of grounclwatcr

SSf

ni;Inncr. cari

agricultural

first,

particularly

;~spcct of the sustainability farmers

activities. CiIn spread

the managonicnt

IO recognized

of

options.

may Inck the capacity

in ;I sustainable

sniallholrlcr

The

littlc

they

is twofolcl:

outsitlc

:ictivity

is charactcr-

off-farm

illld

other

cndogcnous

may feel

an important

dcgrcc

many

such irrigation

antI

AfriciI

by which

tliscussion

who tlo not belong

systcnis

f;rrniing

farnicrs,

, alongsitlc

fact rcndcrs

govcrnmcnts

hand

irrigation

of both

to sonic

foregoing

(cxtcrnal)

tics of irrigators other

the

or c’vcn the main.

of sub-S:rhar;rn

is by its n:tturc

This

cxogcnous

one’ hand

inconic

irrig:rtion

governments.

open

of

as the only,

ccononiy

the that

is rarely or

manage

on

sonic

f;lrmcrs for

and

large in

SSI

maintain

or

the

not-so-large

control

all

the

irrigation).

clearly

dcfincd.

;idapt;Ibility

I,crt,,l U,YCf’oliq

in

the

The fact

f VW Vol~,rc

idea implies of

real

I I Number

or

4

pottrntial trade

threats.

A

or ovttrcome

and future Tht:

main

problrms threats

An

with

the concept

to be considered.

activity

may be judged

and economically

is onr

which

can somehow

to the benefit

of present

sustainable

lit

in two ;Lre;ls:

and second,

technically.

first.

the scope

the time

horizon

environmentally.

at ;L particular

point

in timtt.

in

socially

and inderd

it

may have been going on successfully

for :I few. or for many. years. Then

one single

3 fuel

factor

may destroy

(eg a devaluation. ;1s unsustainabk;

had had its day. The

and times

C;IS~’ of low-lift

fies this

well.

vcgetitblc

For

motor

In

ilIlt

slrtrtlrrj

into

possible

h;tvc

punilx thrc;It

of

situ;ition

proved

to

circumstances.

its

coulcl cithcr

recur

gcncraliz;Ition Inorc

Such

and

or

view

nl;IniIgc;Iblc;

and

the

highly

vol;rtilc

in this

paper.

political

multiplicity

cnvironmcnt;d. to

the

potential

of

conllict

t:tin;lbility

and

rcccnt

13ilIlk symposium

hilSirl

IllilkCS

c:innot rcscarch

prcscnt

w:iit on

the

this conflict for

fully

which

gcn~r;1tion,

prcccdcncc

needs

over

those

initiill

brOild

;Irc gcncr-

thrc:its

cm

bc

niorc

;Iny

the of

of the regions

rural

policy,

would

piirticulitrly of future

of

poor.

and

The

Of poverty

idciilly

bc

its poorest goncrations.’

the

the

SOdill,

drilWS

iIttl2n-

the

ni;ijor

cnvir0nm~ntal soil

sus-

for future

conclusions

of

II

in the GilllgCS

irrigation

Ict illl~IlC

in

consiclarcd

context

rcsourcc

on gr0undwiltcr the urgency

ilnd

only

CiIIl

(tcchnic;ll.

prcscnt

rcquircmcnts

the

OIlC

ilctivity

conflicts,

In the

It is impril~-

IhrCiltS;

sustainability

if alI

insignifi-

circumst;mccs

it ViiIbk.

dcvclopmcnt

settings

on

juclgcti

cxtcrnd

c’XOgCIlOUS

i~lmost

is sustaimtblc ilntl

itIs() 11~;~

st;irk:

and

;ipl>ropri:itc

circumst;lnccs

ill1

;Ictivity

pertaining

dcvclopcd

such policy

the

the

to conilcmn

was

those

cviIlu;Itcrl

the groundw;ltcr

gcncriltions) World

th;~t an

trade-offs. both

but

to sust;Iin;lbility

CXp0ScS potential

is bctwccn

(protecting

fell

I’ctrol

rcvcrsc

unrc:isonablc

cxtcrnal

been

viewpoints

for

need

mcillls

and economic

ccimoniic)

011ly it.

rlcc;dc,

sust;tinability,

gr;du;il;

have

of

to ch;lngc.

more

cdl

for

Icss prdict:lbIc.

all possible

fragility

last

oricc

ch;lngccl,

Of

cnvironmcnt)

ilCC~~UIlt

st;lrtsd

overtook

SC*: rather,

thrc;lts

if prcscntly

the economic

i~cknl)wkdgc

The

then

threats

t0 tilkt_! into

lion

irncl more

cnclogcnous

rc;1son

low price of

1cch110l0gy

ths

they

its conipar:~tivc

cvcr.

notion

inhcrcntly

arc

iI pr;tctical

(cspcciillly

for

of view

which

A ni;ljor

cvcrits

once

bc maclc: intcrn;ll

l~rcclictablc,

potcnti;d

ticill

or bc gone ;I l~rilgIlliltiC

can

cot:tstrophic,

h;kving

lost

thc

bc quite /wr

small

numbers.

the point

rcccntly

;lIlrl

ovc’r

It would

small

IOSOs,

cstraortlinarily

incrc;iscs could

;IS unsust:~in:iblc

In clcvcloping

tl;~y.

exemplionto

returns

systcnis.

h;ls only its

from

hilViIlg

the

sust;lin;ibility

and

both

cstcrnal

lxicc

in the ncdr future. technology

cant

which

bc that it

in I:lrgc

financial

lifting was

in

their

ptrol

cithcr

ally

water

the

introduced

tlispl:lced.

uIiprcdict;Iblc

further

water

better

lxInil>s

;I condition

when

Nigeria

used to lift

attractive

largely

would

:~nd through

were

r:kthcr

.s/rrrtf~rj‘ W;IS sust;iin:Iblc tlcclinc

1970~.

wcrc the

of petrol

in Nigeria.

The

late pumps

w;is

the apl’r”l”iatcnuss petrol

the

illSO

over other

aclvant;~gc

collapse)

have now changed.

in northern

the slrcrrl~~was

systems

pump

offcrccl.’ The

or a market

the conclusion

dry sc;~son irrigation

centrifugal

of convcnicncc,

rather.

;lnd circumstances

centuries

g:lrdens.h

petrol-powcrcd Thcsc

crisis

In such circumstances one would be loath to condrmn

it.

such an activity

‘Carter. R C. Carr. M K V. and Kay, M G ‘Policies and prospects in Nigerian irrigabon’ Ouflook on Agriculture 1983 12 (3) 73-76 ‘Carter, R C ‘The development of small scale irrigation in Africa’ Public Administration and Developmenl 1989 9 543-555; Kimmage. K ‘Small scale irrigalion initlalives in Nigeria: the problems of equity and suslainabillly’ Applied Geography 1991 11 5-20; Erhabor. P 0 Efficiency oi Resource Use under Small Scale irrigation Technology in Nigena Technical Report No 148, Purdue University, West Lafayette. IN (1982): Nwa. E U. and Pradhan. P (eds) lrrigalron Research Priorities for Nigena Proceedings of a National Seminar held at the Universily of llorin (20-23 April 1993) ‘Kahnerf and Levine op cil Ref 2

activity

and so survive.

generations.

of possible mind.

sustainable

such threats,

allcViiltiOn further

simply dCtililCd

bilscd. l’hc needs of the mcmbcrs,

have to take

Small-scale groundwater

Ii hx :ittractivc

hccn water

I~iirticul:~r

argued sour02

it allows

irrigation

clscwhcre

the

_woilrid\~;itcr

that

for small-xilc

is

;I

or f~irnicr-nl~in;icc~l

possibility

of incrcmcnt:ll

p;trficularl~

irrigation.”

kvcl~~pu~cnt.

In while

ICilVillg c~mtrcrl of water supply in the h;inJs of individu;il farnicrs: sm~ill f:irmcr groups. Also the source itself is usu:illy less \~utncral~lc

clrouglit

thm

surf;icc

Ncvcrltxtcss. wlcr

is

hririging

;irguc

lh;il

sources.

the t>o(” h;l\L’

whcrc

u~itlcrulilizctl.

SSGWI

~lcvciopriicnl

I,cviw wtcr

w;itcr

* ;ICCCS~ to Idrid. slill

ni;iy

bcncfils

tlcspitc

tlirectly

1hc risks

~irtrl rlcst3itc

cxptoil;itiori,

Ilc

;111d wticrc

;I tx)ssitJlc

10 lhc rumI

;rsstrci;~lcd lttc

with

ctl;tllcrtgcs

poor.

worst,

such ;in appixxifh

the very

‘I’hc

;iclivity

(1 priori

sources

for

in the

vicwpoiot

which

might

tx seen

is king

d~tcrriiin~ition SSI, or for ;iny

currcut

uncoiitrollcil of

coffftnued from page 275 “Carter op tit Ref 2

‘°Carrulhers.

I. and Stoner. R Economtc

Aspects and Polrcy Issues in Groundwaler Developmenf Slaff Working Paper No 496. World Bank, WashIngton. DC (1981); Carrulhers, I ‘Introduction: public sector opporlunity and llmtlations in groundwaler developmenl’ Agrrculluraal Admlnrslrafron 1984 16 169-180 “Kahnerl and Levine op cif Ref 2 ’ ‘Ibid ‘“Carter, R C ‘Small scale irrigation: the need for thorough feasibrltty studies’ Waterlines 1993 12 (1) 1Z- 14

27s

lllui

11, t3c cVnIli;itccl.

;I t&s

groundto

lhc

poor,

rcsc;irch lc;lst,

all

sc:irch

for siist~iill~it~itily.

At

thrc;it

to the sust;iirl;kbitity

ot

of thu suslainahility of groUndWillcr rcother usu, is iiiticrtzntty clifficull. Acluifcr

nc

Ix~unkirics fircl

that

OJ?C

ch;iractcris-

ancl temporal varinbility) is rlc:iiing tvitt1 nrtt or1ly ;I rcsourcc which is ilsetf

(r;iinf;itt

li;il of

for

ilV<>i
stl;iliow

quifcrs

errors

suitahlc

hc 2s ccmpictc

mclior

river

flow)

t-or ;Irc this rc;ison the scicncc , and physiczil hch;iviour. rcoften 3s uiiprcclict;ihlc as tlicir users awl the sponsihic for (hcrii. Ncvcrthcluss. the importance of rigorous scientific rcsciirch in support of grounitw;ltcr dcvclopm~nt sh~lulrl not bc unclcrratcd. It is r:irc for long-tcrui str;itcgic rcse:irdi to tw cspiicitly linkctl to cleVcl0plllc~~l projects and prt)gr;unmcs. When this dots h;ippcn, though. the p~knIIIC;IIIS tti;~t

will ncvcr

and hyJraulic

sp;itial

(xd

hitlticn. hut also ;I spatially tictcrogcmxtus rlcptnJent 0n ;I tcmp0r;itty v;iri;ibtc iripuI knowlccfgc

for

;iml

K:ititlcrt

proriiotc
continuity, pr~q~crlics (gcoiiictry. tics) mici. cruci;ilty. rccti:irg:L’ rates txttt1

2s ;I

groutitl-

vctiiclu

~r~~iiii~l~v;i~cr rcsourcc ~lcvci~)t~iii~jil sl~oitlil iictt wxit for cilhcr or policy proc~sscs f0 tX c0ir~t~tctctt.i2 ‘I‘tiis tqrcscnls. it! Ittc urrcotivcnti(tn;il

or to

is grc;lt. for

SSI

wishctt. of quifcr systcnis hunmn institutions

as coutcl

It Tilcl csploratictn in

Africa

is

hc

:lllcf ~V~iiUiitiOIl

:i

ncglcctcct,

but

important.

subject

to drought

in recent

hydrology

decadt~

of these

requires

SSGWI

research.

for

The

the ncd

Low-cost

low

capital

cost

become

and

still extremely digging)

ing’.

bailing

high.

and

techniques

ttdniqucs.

n’lncc, ‘

yields.

activities

potcntinl

their

as

such

great

potential

too. that small.

cost.

thcnl

collector

2s the

Other

less

well

projcc1

to

rigs are

and

tcchniqucs

suscclXiblc

vibro-

in Africn.

drilling

operation

niainte-

f(Tr improving

drou$it.

of the

are

;IS ‘sludg-

and

for dissemination modern

hccn

oppostd

such

uashburing

indigenous

is

costs

(as

methods

cvcn portahlc,

for

low c;lpitill

mal;iIig

ilIlCl

Asian

h:ls

drilling

bvcll-boring

augering.

these

This

conventional

Traditional

water

for

access to ground-

years.”

traditional

hand

point

paining

recent

where

modern

their

well

as

well

exist.

drought-proof

starting

for

in

few if any

still have

It is encouraging,

demonstrating

known

in Africa,

well as mm

;IS

the

reliable.

technology

better

necessary

particularly to

traditional

and

has

zone

aquifers.

sources in order to be sustainable. The appropriate well construction techniques. water

of the semi-arid

for undrrstanding

susceptibility

rtzinforccs

incliidc

British

Geological

Survey. Well

will

well

siltation,

s;incl-pufilpirlg

wells.

ni;ilcri;ils

screen

pkrstics

size

use

of

s;iIid-l~iiliil~iIi~

The

Iwo

and

main

gy iIrC,

first,

l~llt

issues

c;iIi

classed

bc

brodly

unclcr

pumps

using

clcctrical

@ nioclcrn

pumps

using

rcncwablc

w;itcr-lifting

context

the

word

which

rcquirc

know-how.

no

Thcrc

not 211 of which lr;dition;il

An~olil”)

rcccntly

woulcl

rctlucing

to

tcchnolo-

cncrgy

SCCOIld.

all the technical

II;IS

~CCII

is ;I wick

Nigerian

still

rilngc

COSlS

:rspccts

niorc

~OIIC

thiln

hcaclings:

have

which

hc unccononiic.

of

of trarlition;ll

bscn

of

Africa,

tcchnologics power,

aI~iIna1

materials

or

waccr-lifting

and

technical dcviccs.“’

In some CilSCS longstandwith

above),

pumps

in others clsewhcrc

;I significant

tcchnologics whcro

modern

and

traditional

is prol>ahly

of ‘traditional’ parts

or

SlIpl>lilIltCd

mcntionctl Thcrc

to mc;ln

IILIIII;II~

inputs

h;~vc long

hecn introducctl. to other

is taken

hccn

fuels;

sources.

for grounclw~itcr.

sIIN~I~~~

the dissemination Africa.

three

or fossil

using

cxtcrnal

;1rc suitahlc

tcchniqucs

of

way

;~bstraction ilIlll

this

cncrgy

locally,

‘modern’

tcchniqucs

northern

power

‘traditional

h:~vc been dcvclopccl

p:trts

illWilyS

dcviccs;

which

for

sh;illow

Of

long

;I

to discuss itntl

tr;iclition:rl

still

go

dcviccs.

moclcrn

only

much

is not the place

l

ing

ClUillity

of grounclw;rlcr

l

(the

f:or

;irc ncdrly

H.CII tIcsign ;I1111 lo bc tlcsirctl. Marc widc-

lllC

woultl

casings.

slccl)

and ni:iintcnancc.

and pumping 15

Equilmicnt

this

;lnil

of

to us12 the

clscwhcrc.

xlcrli~r~cly

In

it is irnp)rtarit

screens

sources

problems

problcnis.

siltarion

This

to avoid

corrotlil~lc

Icavcs

ol’lcn

sustainahili~y

lit’ling

well

th;ln

gcotcstilcs

c;Isc Of rcpdir

antI ;tvail;lbility. of water

for

of constructing

Iii order

corrosion,

IlOWiltl~lyS.

control nioclcm

tcrni.

and

(r;rthcr

Ol‘ choice

slot

spread

of the process

in the long

Cll~illi~y riialcrials

irrigalion tllc

part

011~

bc rcli;lblc

iIpl7ropkitc “‘Koegel. R G Self-help We//s lrngalron and Dralnage Paper No 30. FAO. Rome (1985): Blankwaardl. 6 Hand Dnlled Wells: A Manual on 9ting. Design, Construction. and Marntenance Rwegarullla Water Resources Instrk~le. Dar es Salaam. Tanzania (1984); Melianu. A ‘A simple melhod of jelling tubewells’ Waterlines 1983 1 (1) 6-8; Carter. R C ‘Groundwater development using jetted boreholes’ Waterlines 1985 3 (3) 16-20; Morgan, P Rural Waler Supplies and Sanifalton MacMillan, London (1990) . “Fraenkel. P L Waler Lilting Devices Irrigation and Drainage Paper No 43, FAO. Rome (1986); Kenna. J. and Gilletl. f3 Solar Water Pumpmq: A Handbook Intermediate Tech&o& Publications. London (1985); Barlow, R. McNeils. 6. and Derrick, A Solar Pumping: An Introduction and Updafe on the Technology, Performante. Costs. and Economics Technical Paper No l&3. World Bank. Washington, DC (1993); Lancashire, S. Kenna. J. and Fraenkel. P Windpumping Handbook Inlermediale Technology Publicalrons. London (1987): Fraenkel. P L. Barlow. R, Crick, F. Derrick, A. and Bokalders. V Windpumps: A Guide for Development Workers Inlermedrale Technology Publicallons/Stockholm Environment Institute ( 1993) IsKennedy. W K. and Rogers, T A Human and Animal Powered Waler Lifling Devices: A S/ale-of-fhe-ad Survey IntermediLondon ale Technology Publications. (1985) “Serrano. V. personal communication

is only

drilling

which

from

modern

(cg h:lvc

potential Asia,

itnd

technologies

Where relatively diesel

rural electric power is available ancl cheap. and electric motors are pcnerallv

or petrol

rural

parts

easily

of Asia.

availabk.

significantly machines.

Both

and

petrol

common

tion

and

from

for

the

while

ciecp

water suction

lift

:thout

pcrcists. clcpth

SSI

and

not ;Irt’

Nigeria

m.

and

In

Asia

so it is

the pump

this

there

for

pump.

by suction.

6-7

provitlcs

art’

Africa

mc>tor

hy loc:iting

African

than

in man!

petrol-powercd

(petrol)

normally

In

in

in northern

groundwatcr

is often

pumps

small

own

than

tahlc.

this condition

uclls.

the

for their

no dtxpcr

to deeper

to the

ekctric

prefcrenctz,

pumps

t:thles

rcliahle

available

than

farmers

it

more

is an option

and

units

portahlc

small

xct’ss

nt’nrer

ccx~imon,

diesel

dicscl-powered

to gain

pit.

Icss

nccnunts

to water

electricity

so in Africa,

cmallcst

and

this

and

while

it is rarely

of individuul

limited

\vide

ttowcver.

The

larger

esample. are

units.

reliahltz,

practice

is little

in ;I is not

compcti-

;I convcnicnt

limit

to

over-ahstractit,n. Modern SSGWI yet

uind-

and

in Africa.

hut

wiiicsprc;d.

f Iuni~~n-

of ‘motlcrn’

ni;itcri;ilc

by’

(q

v;tricty

sinildc

solar-powered the cnpitill

pumps costs

or anirrial-l,cl~~crccl

and

ni;lnuf;icturc

rope-;inti-w~lshcr

I~u~kct-;irirl-roI,c

have

;trc still

potenti:

and

irrigation

their

for

use is not

pumps.

whcthcr

or of the ‘intcrmcdiatc

pumps).

water

some

high.

tccliriol~b

also less co1iini011 than

arc

lifts,

at IC;lSt in Africa. I,OCillly m;lnuf;Icturctl lrc;idlc pump< arc niorc witlcsprc;id in Asia, rkyitc \onic trials in Africa with thcsc ;~rid ollicr pmp ty~xs.‘~

Tlic

ccononiic

vi;lhility

~~roduclion. water

irrigation

irription

is

is not

vi;ll?ility

I‘hc

water

in

cstablishnicnt

of

and

hccn

the

‘I’hc

scrvicus.

;ind

scrviccs,

the

is not

punip~ii

Nigcrk

fuel

in

(ic

then

natural

I9SOs

pump sp:irc

of wells ;~nil

;inil

surfxc-

only possihlc tcchnologics, the

wx

p:lrts

prcvitlcnt

sub

economic

costs

and

01

grountl-

prxtiscii),

thu

providing

costs

sc;ison;ilily

~rounclwatcr

of well

supply

scrviccs

of new

rcquircs

SSI

at

which

afforii;~hlc

h;tvc

alrc;dy

ncvcrthclcss to

;irc

may

th;tt

which

xrc

sust;~imhility

to

for

out

anti

of

well

niaintcn:incc

sector

provision

xccss

of

c>f threats. in Tahlc

;illci-riativcly

of

the promotion xivicc.

irrigation potential,

alleviation

summ;lrized

in relation trxlition

to cxtcnsion

significant poverty

cspccially

is ;I strong howcvcr,

to ;I number xru

carry

weak, thcrc

groundwatw have

scrviccs

c;m

repair

hc unimportant;

but

;~vailability.

potcnti:tl.

gcncrally

h:ivc

its the

of privntc

Whcrc

f;irmcrs

;lppcars in qzncral

pump

obvious

sector.

this

vulncrahlc

threats.

;ind

to

rcquircs

which

tradition

;I seemingly in Africa

rclatccl

often

private,

pumps

of small-scale

SSGWI

production

f;lrmcrs

or

is little

irrig;ttcci

irrigation

is closely

by small pul~lic

cicspite

informal

Threats

technology

thcrc

sm;~ll-scale

thcsc

of

outlets

low

of

In Africa

Although R D ‘Manual recovery of shalfor lrrigatlon by African farmers’ Proceedrngs ol fhe lnslrlulion of Cwrl Engmeers Part 1, 199 1 90 10 1l- 1020

on

siiiall-sc;ilc

on Cilpit;lland rccurrcnt

supply

very

Vulnerability

‘“Faulkner.

technology

provision

whether

Extension

low groundwater

pumping huckcl-lift

uptake

irrigation

construction,

crop

on ;11iii

northern

;~fforci;tbility

instilutions.

to

Whurc

nicntionccl.

Groundw;ltcr

such

cicpcndcnt

ilcp~ndcnt

of subsiciixd

prices,

is highly

to m;irkcts.

reliant

wiilcsprcxl

irrig;ltion

txcausc

SSI

possilk

is very

pumps.

of

;incl xccsc

price

This

not

only

in particular. section

for it is

atltlrcsses

I. portr;lycil

x

c;liiscs

of

Table 1. Checklist of components of, and threats to sustainability of. small-scale groundwater irrigation.

component

Potnrtial threat

Groundwater resource

Long-term drought. affectmg recharge Upstream development. affectmg recharge Over-abstraction Interference from nearby wells or competmg deep wells Leaching ot agrochemrcals and salts Salme tntrus~n Capstar cost Poor desrgn. especially in fine-grained sedments and corrosrve groundwalers Poor consfructton qualtty Capital cost Avallab4ty and cost of pump and motor spares AvatlabMy of repalr and mamlenance services Foreign exchange requtrements

Groundwater qua& Weii~rehofes

Pumps

fnilurc.

Since

fililllrc

of

threitts

is much

thcrc

irrigation

which

;trc

specific

Ill~llY~~~~~~) irrigation. ‘T’hcsc

thrlXltS

fxtors)

dealing

with

discussion

&vi&d

into

anti growth

those

of ~r(~~irl~iw;lt~r

or cnvironmcnt

fur the ifltliVirlLlill

rjl’ the

technology

of well &sign

tllAltcllancc issues,

ilsptots

hcrc.

it

human

but

is

Ouality

flllldilfllCflt~ll. pcrformancc

of

filcilitics

rcpilir

reliability

relics

:lflcl

t0

F L ‘World Bank irrigalion experi-

Resources Development ence’ 1962 1 (1) 65-75; Van Steekelenburg and Zijlslra op tit Ref 3; Carter op cif Ref 3 Z”Barrelt, H. and Browne. A ‘Environmental and economic sustainability: women’s hor!icuRural production in the Gambia’ Geography 1991 76 (3) 241-248; Carter op tit Ref 1 “Kahnen and Levine op cd Fief 2

the

or

in

thrc;its

to

in

thcsc

Wliltt2

;irc

supply.

Thcrc

of

rind

;trc

the

lhc

r~i~lly

and

rcxly

the

ilCCCSS

longevity

tk

;ITC numerous

non-sust;linability fuel

iIrC

‘hardw;rre’

which

ilffL!Ct

directly

p;lrtS).

clcviccs, priil~~lrily

(cmibling

‘I’hc

illld CiISL! Of

construction,

atltl

to the

is ;lhstr:~ctecl.

fitctors

design

institutions

dicscl

group,

waster-iiftiii~

sight

is uncctntrc)llecl

int~rf~r~n~~ wittcr

(i-7

thcsc

m),

to

;tnd

cxilmplcs

pumping

in

technology

m;lintCn;lnCC

tahlc

howcvcr.

farmers

groundwatcr

SSf

may

of

internal

;Ind

suffer

equally

clown

to

Icvcls

the m;ty

itlkviilti<>n

limit

is possible. not

hc very

in iI rclittivcly

short

conflict

may

have ;ICCCSS to submcrsiblc

deeper WCIIS, then formcrs irrevcrsiblc sstbacks. This

the biggest

is by

suction

Of crop loss and filrnlcr farmers

Ic;lci-

punlpin~

abstrxtion

outcomes

can rcstorc

important,

~~v~l~)pni~nt,

Whcrc

further

ultimate

If srtmc

is probably

in poverty

no

ilmOUflt

technology,

walls

sm;tll-sci~lc

LcViIlt).”

the

by this time.

pump

shallow

drawn

be

which

rechitrgc

il ccrt;lin

h;lvc cluvclopccl or turbine

may

circumstances

p~riotl;

but

~roun~w~It~r

:inci over-;ibstrilction.

hcyoncf

since subscqucnt

ilIld

of f;trmcrs

inirnorli;ltc

groundwiltur

itl~tvJt*rcwt*e. A second,

serious.

from

the

thrc;tts).

or f;irmcr

instituti~~r~~ll

water

of

on petrol or 31

the

(gCn~r;lIly

Waler

SSI.

cngincs.

well

suction,

“Holes.

irntl

SpilrC

t0 Sllst~iinilbility

to

first

control

(3vlJr-c~hsrr(i~rinn std thiX!iit

fitrrrlcr-

from

iltld thC pcrform;incc

pumps

m;tintcn;tnco

Africa

combustion

farmer

hy which

At

of the f:lrmcr’s

sub-Suharan which

the

those

(cntlog~ou~

SSI

control

(csogcnous

;uici construction.

irrigation

of

iIl~p~)rt~ii~t

arise

which

C~rorrtrcl~tw~i~r trhslrcicYirm fidlrrolr~,~_v. ‘I’hc most rcli;lhility

for to

Il1rccll.s

sustilin;lhility, qu;ility

limited

sn~all-sdc (in the SC’IISC of to grounilwittcr-r;upplic(ti

to

hf

pm&cc

economy

I;tltlo,~iVl,~lr.s

Unclcr

is

anti those which tic beyond the immctliittc

the wider

ing

the re;~sons

hcrc

itnci in particular may

iirtplciilcnt;ttirtit.

literature

in gcncrill.‘”

single

(the ‘hiits

chillkngc to the poor’

irrigating threat

IO

to the USC of of Kithncrt

Groutztfrc~ukr

Leaching

render

irrigation

use

estuarine

areas

third

main

irrigation

such

or

a diversity

Thrtwts

flous

dcvclopmcnts

can of Lvatcr

arid zone of Nigeria construction affcctccl

of

flood

plains

of the

rcsourccs

of small-scale

resources

SSI

in

such

can

further

coastal

that

or

they

other

as can

purposes.

are

In the

irrigaticjn rcchargc,

rivers.”

kind

;IIKI has

in the flood-

of competition

the irivisilGlity

not given

it dcpcnds

northcast 197(ls.

schemes.

groundwatur This

rainfall upstream

since the early

formal

large.

as rcductxl

recharge.

of drought

is still

on which

cithcr

to SSCWI

factors

in large part from

irrigation.

arid so the rcsourcc

threats

for

nncl Jama’are

results

for

over-pumping

ground\vatcr

and possibly

I Indejia

quality.

grounchvater

headings.

to supply

cstcnt,

water

2nd

;I combination

dams

to sustainahil-

intrusion.”

Natural

affect

to shallow

unaccqtahlc

of external

rt’soffrcc.

fo tlrc nwft’r

river

chemicals

use,”

broad

threat

can have on groundwatcr

groundwatcr

domestic

hertz under

rndogcnous

itself

may lead to saline

is such

consided

and

that

of salts and agricultural

eventually

There

The

quu’li~~.

ity is the impact

the recognition

is vulncr;ihlc

for

and informality it dcscrvcs,

to such ticstructivc

conipclition. “In much small-scale irrigallon. groundwaler sources used for Irrigation are also ullllzed for domesllc purposes. Water quality conslderatlons therefore lake on a double slgnlficance. “‘Shah. T Susla/nable Development ol Groundwafer Resources: Amrapur and Hussernbad

lessons from Vi//ages, lndia

Ufr(*~f/.F

(often

l’hc

and Sustainable Resource Developmen of a Sahelian Floodplain Welland Report to

fuel

lion of Welland Benefifs: Ihe HadejtaJama’are Floodplain, Nigeria International

lnstltute for Environment and Development. London (1991); Hollis. G E. Adams, W M. and Aminu-Kane. M The tfadejaNguru Weflands: fnvironmenf. Economy, and Sustainable Developmenf of a Sahelian Floodplain Welland International Un-

ion for the Conservation of Nature, Gland, Switzerland (1994) ‘“Howsam. P (ed) Wafer Wells: Moniformg. Marnfenance and Rehabilifafion Spon. London (1990) 26AWWARF Evaluafion and Resforafion of Wafer Supply We//s, American Water Works Association Research Foundation, Denver, CO (1993); CIRIA. Monrforing. Mainfenance and Rehabilifafion of Wafer Supply goreholes Construction Industry

Research and Information Association, London (1993) Z7Smoul. I ‘The management of irngation tubewells’ in Howsam op c/f Ref 25

viability

of thcsc

inputs.

and sparus,

is

dcpcndcnt

supplies,

tlic sust;iin;il3ility

of such

xtivitics

m4y

cxchangc

is involvccl

2s

of the systems.

for pumps lx

on

as well

irrigition

parts

very

relics

on

and cngincs.

scnsitivc

to the

in the purch;lsc

of

may hc high.

economics

politics)

cricrgy

Much ccroiilitlw;ltcr-fctl

If foreign

in national

SSG W I

or

on fuel ~intl spare

vulnerability

adjustment

fuel

thrcatcn

~*irrhilify.

and thcrcforc

Changes

with

spat-c parts.

economic

prices

rill

problems

frt c0ttfrtttfic

pumping,

Whcrc

~c~c~lftricxl sfr.sftritftrl~ilil~.

pumps.

importcrl)

7’IfrrM~

Irrigation Managemenl Network Paper 901 3d. ODI/IIMI. London (December 1990); Barrett and Browne op cif Ref 20 24Adams, W M. and Hollis. E Hydrology

the Hadejia-Nguru Wetlands Conservation Project, International Union for the Conservation of Nature. Nigerian Conservation Foundation, Royal Society for the Protection of Birds (1987); Barbier. E B. Adams, W M. and Kimmage. K Economic Valua-

I0

motorizctl

(cg devaluation

may catastrophically

;is ;I result

affect

of structu-

the prices of fuel and

spares.

Management and monitoring of groundwatcr l‘hc

sustaimihility

large

cstcnt

sonic has

form

attention have

monitoring, holes.“‘ ilblC,

the

records

levels

need not

cquipmcnt. dour

and of

pumping

Obvious

good

of

hcst

would

and

arc

rcccntly

UK

water

practice

water

for

supply

not usually

lx

the

borc-

universally urban

to ;I

involves

only

US

of

practice

dcpcncl

applicSupply

WiltCr

readily

avail-

bc appropriate,

with

systems.

for

mcthocls farmers rate,

that would

to adopt;”

pumping

much

time

water

quality

and taste.

The

to large-scale

advocated

monitoring

take

guidclincs

;lpply

will

managcmcnt I lowuvcr.

arca.

rehabilitation

lllilinly

and cost, of

to this

produced

irrigation

arc simple

daily

paid

principles

Optimum

maintcnancc.‘”

ilnd

and the mothods

to time

dcvclopmcnt

is m;lnagcd.

maintcnancc

While

Thcrc

colour.

it

recently

to small-scale

regard

any groundwatcr

been

thcsc: guiclclincs

systems ilblc

how

of monitoring

proper

inclustrics

of

on

nor

involve changes

for

duration

and

expensive CilIl

be

inStimcf2,

keeping

groundwatcr

or sophisticated

noted,

es turbidity,

In the case of regional long-term general

depletion

over-abstraction deterioration

institution

needs

of groundwater

and/or

reduced

of groundwater

quality.

to be responsible

resources

recharge,

due to interference

localized groundwater The other question between: long-life

(a) high design.

from

other

contamination. with operation

initial

and high-quality

may have higher

operating

or national

farmers. It should such as well yield abstracters

maintenance

construction

or

is the choice

costs as a result

low operating costs and low maintenance lower initial installation costs for simple

to

and such a body

neighbouring

and

installation

due

in cases of

a regional

for such issues.

needs to be receptive to information from individual also be able to arbitrate over localized problems, depletion

or

of high-quality.

and equipment,

but with

frequency and costs; or (b) short-life technology, which

and maintenance

costs or high replacement

frequency. It is likely that in many cases individual farmers with limited time and resources will bc unable to adopt best practice on their ow~1 initiative. An advisory

and training

govcrnmcnt. within

the

from

service

needs to hc availahlc

a qiIasi-g”vcrnIIiciit~il Owl1 co0pCriltiVc

filIXlers'

either

extension

from

service

or

the from

SyStcIll.

Legislation and control 1,illld

illltl

SSGWI.

rights

water Existing

rules. concerning

;rlld

h;lVc

controls

and

whcrc Thcrc

arc

controlled

many

thcrc ncithcr exists, national Icgislation. it fits with

Lancl

cxamplcs

by long-cstablishctl

rights

compared

to

for SSGWI

ilTC highly Ivy

illltl

ICgiSliltiOll

;irc

whcrc

land

rules of lociI

filctOrS: llolilics. iicccssary

problcnis

water

arise

rights

arc

and thcrcforc whcrc

custom

the more

likely

it is to bc cffcctivc.

;Irc often

a complicated issue but still relatively simple less tangible water rights. Out of sight and less well groundwatcr is the most difficult to deal it has not yet been possible for all the

states to even agree on a definition

1lowcvcr,

and

custonl

illltl

rarely

‘I‘hc

variahlc

lllilny

cllStOlll,

of SLICll

nor is thcrc riced for, statutory or institutionalized I lowevcr, when this dots hccomc ncccssary, the

understood than surface water. with. In the European Union mcmbcr

of

to the control of enforcing

iiillucncctl

SOCiill culture

clillliltc,

slJc;ikiiig,

hCCl1

IXliIlillg

the IllC;lIlS

natural rcsourccs cxcccd liunian demand. scarce rcsourccs IlilVC to bc sharccl.

whcrc

closer

issues illltl

the use of groundwatcr

from pI;lCC l0 pl;lCC geographical locality, C;cncr;llly

arc fuIltlaIllcIltal

rules or IcgiSliIti0ll,

in many

tied to land rights,

C:ISCS. groundwatcr

rights

of what have

and this can in some circumstances

groundwatcr been

is.”

traditionally

be an cffectivc

relationship, whcthcr the groundwatcr is a finite resource to be mined or whcthcr it is part of the modern hydrological cycle and is renewable. Thcsc distinctions do, howcvcr. bccomc important when considering the concepts of ‘ownership’ and ‘right to USC’.“’ I’hc ‘%kinner. A C ‘Groundwater: legal controls and organisational aspects’ in Downino. R A. and Wilkinson. W 8 (eds) Applied Groundwater Hydrology Oxiord ~S&nce Publishers, Oxford, UK (1991) %aponera. D A Principles of Water Law and Administration A A Balkema, Rotlerdam (1992)

.

opiions

individual

coIn~~only’~IviIilablc-iIrc: rights - based on historical

right

and common

law (often

favouring landowners with rights passed down through the family, so leading to fragmentation to non-viable Icvels); a nationalized rights and rules - based on statutory legislation; control is by ;I regulatory licensing system aimed at ensuring sustainability in terms of both quantity and quality;

283

l

communitv

rights

and

control

- this

is the

most

effective

as it can

handle both the principle of eqdahlr II.S~J ancl ;ilso the principle of tzo harm to others. It dws, however. require ;I single h~~mogcneous community in order to be successful. The current tendency in many countries. especially with increasing demands on limited water resources. is t.o introduce national ownership and control of groundwater resourct’s.“’ The principle of historical rights is not sustainable ;IS it tends to preclude the best USC and the fairest distribution of water rcsourct’s. Legislution, if poorly prepared ;ind enforced, could he more of ;in external thrcnt than n support to SSGWI. It needs tu introduce and bc supported by appropriate institutions which deal \sith bvnter rcsourcc planning and management ;IS well ;IS cnforccmcnt. It ncccls to integrate activities :\t regional, c:ltchmcnt or river basin I~vcl. ;IS k;cny:~, Jordan :~nd Nigeria :Ittomptcd to do in the late 1970s :rntl early IOSOs. Planning and rclatod Icgislation need t<) britlgc the gap bctwc.crl w:ltcr m:tnngcnicnt at the river h:tsin :~nd local Icvcls. Thcrc :IISO ncerls to bc integration of water policy and law with other planning issues such :IS land use. and economic and social dcvclopmerit. In

1002

owncrshil1

participate

Mcxictf of water

in

introducctl rcsourccs.

their

Icgislation but niakcs

Irrigalion

ni~tn~igcniurit.

Users’ Associations. ;iiliilinistr;itiori and

with

liivcr

;I public

which corifirnls the it possible for water atlmiiiistcrcd

f3asiri Councils

to look

Rcgistcr of W;itcr

nation;~l

users by

;Iftcr

river

to

Waler b;lsin

Rights. H’;IS ust;iblishcd

by lhc Icgisl;ition.” Nepal rcsourccs

introtluccd

Icgislation

in the

Kingdom

in IW!

which

vcstctl

ownership

of water

of Nepal

:mtl subjects w;ltur use to liccncc rcquircmcrils (cxccpt for limitccl domestic and irrig;ition 115~s);iiiil the paynicnt of w;itcr ch:irgcs. I1 also proviclcs for the cstahlishnicnt ;~ntl kg;11 stalus of W;rtcr Users’ Associ;itions.-”

Conclusions and policy implications is ;i rarigc of views, both in Ihc litcr;iturc ;~ncl in practice, on lhc right way to go about groundwatcr tlcvclopmcnt for small-sc;ilc irrigition. At one cstrcmc ;irc those who see the remaining untaplxd grounclwatcr ;IS ;I rcsourcc to bc tlcvclopccl urgently on behalf of the rur;ll poor - the urgency being the prcscnt reality ot’ poverty, combinccl

Thcrc

with the rapidity rcsourcc.

JOBurchl. S ‘Current developments and Vends in the law and adminlstrallon of water resources: a comparative state-ofthe-art appraisal’ Journal of Environmental Law 1991 3 (1) 69-91 “Law on Natural Waters “Water Resources Act 2049

with

which

wcalthicr

farmers

arc alrcacly

At the: other cxlrcmc is the viewpoint thorough rcscarch should preccclc careful

that

IcgisLltion, togcthcr water managcmcnt

should

with cffcctivc for SSI.

control,

urges

policy

exploiting great

the

forrnul:ltion.

caution: ;mtl

underpin

ground-

The present authors would propose ;I more pr;igm;itic approxh. Recognizing the impr~lctic;ihility of cvcr arriving irt ;I full unclcrstantling of acluit’cr bchaviour, or king able to prctlict how the rcsourcc will actually bc: used, it is ncccssary (or exploitation, monitoring, motlclling and policy formulation to take place concurrently, ;IS flcxiblc processes.

allows xccss to the quifcr

Exploitation

antI

monitoring.

approxin~atl:

sufficiently

The

results

niorc

and

flexible

to

of

such

for rncasurcrncnt, ohscrv:ltions

allow

CIOSCI~ to reality. And respond to new knowlcdgc. niorc

observation modclling

to

if policy ciln bc and sufficiently

realistic

about

the effectiveness

use of the resource Small-scale

makes

irrigation,

a significant.

undervalued

of legislation

and control,

from

whether

but often

contribution

groundwater

unquantified,

to African

or surface

unrecognized

economies.

The

small

farmers.

Tasks

which

monitoring,

can and

should

to bolster farmers

or

Icgislntion

provide

important

the sustainability

control

support

cannot

functions,

services

undertake,

must

should

not be applied

retrospectively

be carried

Icgislation

to support

them,

should

water arc

rcsoiirccs

also

Action control In

rcsc;irch

is ncctlcrl Of

may bc suction

the subject

Ncvcrthclcss

of groundwatcr Africa’s

by

issues ilnd

the cffcctivcnuss CXpl0itiIti0Il

AfriCil

the

technology

with agrccmcnt

acluifcrs.

of ~ilturnativc by

irrig;itors.

arrangcmcnts

Icgislation

the

of grounrl-

only possibilities limitations (cg

institutional

nianagomcnt

of land and the

is full integration

triInshwnd;Iry

lo gr0lIndWiItcr

by

decided

user groups

coopcriltion of

to cvalu;itc

imposed

those limit).

of investigation

Sub-Saharan

Intcrn:~tiond

Sllb-S;lhilr;lIl

thcrc

for the wiclcr

dcvclopmcnt

in rcl;ltion

Coiinlrics

i~nplcnicntatio~i

the

that

as

out

should

to support

and water

rcsponsiblc

land use. for

stratcgics

Illillly

control diamctcr,

ilnd

ncCcss;Iry

cnsurc

farmers

such

of well can be

policy. but rather it should evolve alongside the dcvclopmcnt and waler use politics. Politics on groundwatcr mnnagcmcnt. and involvcnicnt of individual regional or Il;lti~~Ilill agcncics

to

irrigation.

governments, or chaos and conflict will result. Provision and maintenance services. construction, and pump repair provided most efficiently by the private sector. and governments act as enablers rather than providers in this context. Legislation

of this

in governments of SSI, it is more

of grounciwater

groups

farmer

and

water,

and therefore

‘invisibility’

sector is regrettable enough. but when this results developing water and land resources to the detriment than lamentable. Governments

sustainable

can be the outcome.

should

for well

for the also bc

and comparison.

opportunities

for clcvcloping

irrigation,

whcthcr

small or large SCille, whcthcr from groundwatcr or SUrfilcC water, arc liniilcd. Dryland, or upland, agricullurc will always far surpass irrigalcd farming

in terms

of lad

;ux;l.

Ncvcrthclcss

the relatively

small

;lrc;ls

of

valley I~OttomlilndS, especially those yielding shallow, good quality groundwatcr, can rcprcscnl very important insurnncc and income for small farmers with access to the soils and water rcsourccs which they rcprcscnt. for

the

rlcpcncl

These

rcsourccs

sustainability increasingly

of upon

should the them

rural

bc jcillously communities

in future.

protcctcd which

antI managcd may

need

to