This is the fifth lecture of the course 'Irrigation based Agro-ecosystems' conducted at the Faculty of Social Sciences and Humanities of the Rajarata University of Sri Lanka

1. WRMG 2212
Theory 40 hrs
Rajarata University of Sri Lanka
P.B. Dharmasena
0777-613234, 0717-613234
dharmasenapb@ymail.com, dharmasenapb@gmail.com
https://independent.academia.edu/PunchiBandageDharmasena
https://www.researchgate.net/profile/Punchi_Bandage_Dharmasena/contributions
http://www.slideshare.net/DharmasenaPb

3. •

4. Typical Landscape before the intervention of Mahaweli Program in 1975
Natural
Streams
Tanks built across
Natural Streams
Forests
Forests
Forests
Paddy
Field
Yoda Ela (Main
Canal) along a
Contour

5. Landscape
BEFORE
1975
Landscape
today after
development
KALA OYA AUGMENTATION WITH MAHAWELI WATER
Katiyawa
Wewa
Katiyawa
Wewa

6. Natural
Streams
Tanks built across
Natural Streams
Forests
Forests
Forests
Paddy
Field
Existing Yoda
Ela (Main Canal)
along a Contour
Step 1 – All the Forest Patches in Areas which are irrigable from the Main Canal were cleared

8. Step 2: Meandering Main Canal (Yoda Ela) was straightened and existing village tanks
within the irrigable area below the Canal was removed

9. 3-D view of a Typical Landscape of the selected area after the
removal of existing village tanks and forest patches
RIDGE
Valley

10. Step 3: Distributary Canals originating from the newly aligned Main Canal

11. Distributary Canals laid along the Ridges of the Landscape
RIDGE
Valley
Distributary
Canals

12. Step 4 : Field Canals were constructed to deliver water to the farmlands which were
leveled into basins (Liyaddas) mainly for paddy cultivation. Beds of all the village
tanks were converted paddy fields
Settlement
Areas allocated
for farmers

13. Step 5 : Irrigable Land was then fragmented into 1 Ha allotments to distribute among new
settlers. Balance area above the command of the canals was allocated for settlement
Farmer
Settlement
Zones
1 Ha
Paddy
Farms

14. Aerial View of area as seen today
Area Selected for
the demonstration
Right Bank Main
Canal from
Kalawewa (Yoda
Ela)
Kala Oya
Stream

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•

16. –
–
–
–
–

17. •
–NCP

22. 22
FOREST BELT

23. PROPOSED NCP CANAL

25. •
……..
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•
•
•
•
• , ,
• ,
•

28. Natural
Streams
Tanks built across
Natural Streams
Forests
Forests
Forests
Paddy
Field
Yoda Ela (Main
Canal) along a
Contour

29. Natural
Streams
Tanks built across
Natural Streams
Forests
Forests
Forests
Paddy
Field
Existing Yoda
Ela (Main Canal)
along a Contour

33. Settlement
Areas allocated
for farmers

34. Farmer
Settlement
Zones
1 Ha
Paddy
Farms

35. uyje,s ckdjdi ixl,am
1' iuia: m%dfoaYSh ixj¾Okh
– uq,a hq.fha § ckdjdi ìysjQfha l=Uqre wiajoaok m%foaY mokï
fldg .;a iSñ; jQ m%foaYj,h' ta uÕska wjg mßirfhka
yqol,d jQ ckdjdi ìysùu yd m%foaYfha iïm;aj,g we;s
m%fõYh weysÍhdu isÿúh
– uyje,s jev igyka u.ska iïm;aj, ixj¾Okh taldnoaO
lsÍfï ixl,amhla y÷kajd ÿks' .x.d fødaKs ixj¾Okh
wka;¾ fødaKs yerjqï uÕska w;sf¾L c,h ,nd.ksñka N+f.da,Sh
m%foaYhl taldnoaO ixj¾Okh i|yd jvd mq¿,a iïm;a
mokula we;s lrk ,§‘
– fï uÕska mq¿,a m%foaYhl iudc yd wd¾Ól l%shdldrlï
iïnkaO lrñka ckdjdi ia:dmkh úh'
– fï wkqj uyje,s jevigyka uÕska cd;sl ud¾. c,dhg
iïnkaO jk ud¾.o" jHdmD;sh iy tys jgmsgdfõ k.ro
úYd, m%udKfha cd;sl jfkdaoHdk i|yd úYd, m%udKfha
rCIs; bvïo" mßmd,kh i|yd uymdßudKfha há;,
myiqlïo ie,iqï lrk ,§'
– ixjrAOkhg úIh jq iui: m%foaYfhau fuf;la yqol,dj mdvq
fõ ;snQ iïm%odhsl .ïíï nqre;= msáka uyje<s ckdjdi iudc
ixialD;shg hgúh'

36. uyje,s ckdjdi ixl,am
2' iïm;a Ndú;fha m%Yia:lrKh
– iqÿiq mia iys; m%foaY yels;rï jdß iïm;a hg;g .ekSfuka
úYd, m%foaYhla wdjrKh lsÍug jdß moaO;s ieleiSu' fuys§
fkd.eUqre miao" blaukska c,h nei hk tkï jeäfhka c,h
kdia;sjk miao iqÿiq mia f,i i,ld we;s neõ wOHhkhka f.ka
wkdjrkh ù we;'
– ld¾hCIu kv;a;= lsÍï fyda fufyhqï lghq;= i|yd flá ÿr
we<ud¾. ieliSu'
– m%udKfhka fylaghdr 20 l muK bvï lene,a,la lafIa;% we<
moaO;shla i|yd ie,iqï lsÍu' fuhska n,dfmdfrd;a;= jQfha l=vd
f.dú m%cdjla lDIsld¾ñl yd jdßc,iïmdok lghq;=
l<ukdlrKhg fhdod.ekSuhs'
– m%cd uq,sl ld¾hhka myiq lr,Sug ukdf,i f;dard.;a m%foaYj,
f.j;= iuQy we;s lsÍu' fuys§ mfia irenj" mfia .eUqr"
c,jyk ;;ajh wdÈh fkdi,ld yer we;s neúka f.j;Af;a
wd¾:sl M,odhs;d uÜgu b;d wvq w.hl mj;S'
– ckdjdi ia:dmkh yd j¾Okh id¾:l lrùu i|yd há;,
myiqlï m%udKj;a f,i iemhSu'

37. uyje,s ckdjdi ixl,am
3' ckmÈlhska mÈxÑ lrùu
– uyje,s ckdjdi ixj¾Ok udÈ,sfha ud¾." we<ud¾." m%cd
f.dvkeÕs,s fiajd uOHia:dk" <sx iy úÿ,sh iemhSu"
wvx.= úh'
– ckdjdi we;s lsÍug fmr jirj, tfia ke;skï
ckmÈlhka /f.k taug fmr m%cd myiqlï wvqu jYfhka
fldgila fyda iemhSfï wjYH;djh fuu ixl,amfha
wka;¾.; úh'
– ckdjdi l%shdldß f,i taldnoaO jk whqßka tajd ia:dk.;
lsÍu
– f.j;= .ïudkhlg iduqysl jk fia f.dúìïj,g
myiqfjka weúohdfï ÿr we;s iqÿiq ia:dkj, ia:dk .;
lsÍu uyje,s ckdjdi ixj¾Ok udÈ,sfha wvx.= úh'
– myiqfjka weúohdfï ÿr ie,iqï j,§ nhsisl,fhka hEfï
ÿr olajd fjkia úh'

38. uyje,s ckdjdi ixl,am
4' iudÔh ne£u
– kj ckdjdi j, mÈxÑhg tk mjq,aj,g Tjqkaf.a ;snQ bvï"
Ôj;a jQ mßirh úfgl Tjqkaf.a /lshdjka iy wdodhï ud¾.o
lem lsÍug isÿfõ'
– Tjqkaf.a úúO wfmaCIdjka ;sfnkakg we;' fndfydaúg
mÈxÑlrejka ðj;aùug yd j.dlsÍug leue;a; olajkafka
Tjqkaf.a kEoE ys;j;=ka iuÕh' fï uÕska Tjqkaf.a iudc
iïnkaO;djhka ;jÿrg;a f.k hEug;a wfkHdkH iyfhda.h
m%j¾Okh lr.ekSug;a iduqyslj w¨;a mßirfha w¨;a .ïìï
idod .ekSfï wNsfhda.hg uqyqK §ug;a yelshdj ,efí'
– jdß iy f.dv bvïj, jdKsc uQ,sl lDIsld¾ñl ksIamdokh"
lDIsksIamdok ia:dmkh iy úúO fiajd ixj¾Okh uÕska
úfYaIfhkau m%cdjf.a fojk mrïmrdj i|yd f.dúm, fkdjk
/lshd wjia:d m%udKj;a f,i ,nd§u uyje,sfha wfmaCIdj
úh'

39. uyje,s ckdjdi ixl,am
5' ixj¾Okfha iyNd.s;ajh
– .eñ ixialD;sl mßirhl mdrïmßlj Èú f.jQ f.dú ck;djlg ;ud
lïlrefjl=h hk wdl,amh wNsfma%rkh lrjkq ,nkafka yßyeá mÈxÑ
ùug;a fmrd;=jh' mÈxÑlrejkag ixj¾Okhg iyNd.s ùug wjia:dj
,nd§u kï jeo.;a jkafka Tjqkg bvu we<ud¾. ud¾. yd fjk;a
jHqyhka Tjqkaf.au hehs oekSu ;=<ska tajd /ln,d .ekSug fm,öu
ksidh' fuh m%fõYfha iajNdjh u; oeä f,i r|d mj;S' wdrïNfha§
f;dard.;a mqoa.,hka muKla fuu ld¾hkays iyNd.s lrjk w;r .ï
ìï fmkajd §fuka miq Tjqkaf.a mjqf,a idudðlhska iuÕ m<uq
wjqreoafoau w¨;a bvïj,g meñKSug yelsjk w;r ta jk úg mjq,la
Ôj;a ùug yelsjk mßoafoka m%udKj;a há;, myiqlï ixj¾Okh ù
;sîu w;HjYHh fõ'

40. uyje,s ckdjdi ixl,am
6' bvï mßyrK ldKav f;dard.ekSu
– uq,skau N=ñfha ieÕù we;s yelshdj mokï fldg f.k bvï mßyrK
ldKavh f;dard.; yelsh' uyje,s ixj¾Ok ie,iqï ta wkqj
ms<sfh, lrkq ,enQfha fN!;sl YIH úoHd;aul yd wd¾Ól wOHhko
mokï fldgf.kh'
– mfia iajNdjh wkqj jdß c, iïmdokh hgf;a we;s m%foaY j.d
lsÍu uyje,s ie,iqu jQj;a fuu úoHd;aul m%fõYh oeä f,i
uyje,sh w;ska W,a,x.kh õh'
– jdßc, myiqlï fkdue;s bvï" jeú<s fnda. j.d lsÍu" or
jkdka;r" f.dapr .ïudk wdÈh jeks úúO ixj¾Ok wjYH;d
i|yd fjka fldg ;sìks'

41. uyje,s ckdjdi ixl,am
–
–
–

42. uyje,s ckdjdi ixl,am
8' .%dóh wdh;k wdrïN lsÍu iy ixj¾Okh lsÍu
– uyje,s ie,iqï lrejkaa ixj¾Ok jevigyka yryd
.%dóh wdh;k wdrïN lsÍug yd ixj¾Okh lsÍug
wjOdkh fhduq lrk,§'
– tjeks úhoï uÕska n,dfmdfrd;a;= jqfha w,q;a m%cdj
Tjqkaf.a iudðl uQ,hka m;=rejd .%dóh kdhl;ajh
f.dvkeÕSu m%j¾Okh lsÍuhs'