MANAGEMENT OF HILL TORRENTS Management of hill torrents crossing the Kachhi Canal to reduce the peak flows to safeguard the canal and to increase the agricultural production in Pachad Area Management of hill torrents crossing the Kachhi Canal to reduce the peak flows to safeguard the canal and to increase the agricultural production in Pachad Area Review alternatives to; Review alternatives to; i. Adopt hill torrent management to reduce the peaks or; ii. Remodel existing X-Drainage / Hill Torrent Structures of D.G. Khan Canal and Dajal Branch from RD 0 to RD 531 as per criteria to be adopted for Kachhi Canal iii. Review various modern alternatives for hill torrent management

D.G.Khan Hill Torrents

MAP OF KAHA HILL TORRENT

GENERAL TYPES OF STRUCTURES FOR MANAGEMENT OF HILL TORRENT Storage Dams Storage Dams Delay Action Dams Delay Action Dams Check Dams Check Dams Flood Distributors Flood Distributors Dispersion Structures Dispersion Structures Diversion Dykes Diversion Dykes Cross Dykes Cross Dykes Flood Irrigation Channels Flood Irrigation Channels Flood Disposal Channels Flood Disposal Channels

KAHA HILL TORRENT

SCHEMATIC DIAGRAM FOR MANAGEMENT OF FLOWS IN BALOCHISTAN

SCHEMATIC DIAGRAM FOR MANAGEMENT OF FLOWS IN PACHAD AREA- PUNJAB Cost of Schemes – RS 130 Million Potential Area – 36,253 HA

MAP SHOWING MANAGEMENT WORKS ON KAHA HILL TORRENT IN PUNJAB

PROJECT IMPACT FLOOD PEAK EVENTS/INUNDATION YEAR 1973 YEAR 1973 FLOOD PEAK56,000 CFS (1,586 CMS) FLOOD PEAK56,000 CFS (1,586 CMS) BREACHES - DAJAL BRANCH148 Nos. BREACHES - DAJAL BRANCH148 Nos. DISTYS. DAMAGED DISTYS. DAMAGED - NAUSHERA - NAUSHERA - ZAMZAM - ZAMZAM - ISLAM - ISLAM - ABE-HAYAT - ABE-HAYAT AREA INUNDATED45,000 ACRES (18,220 HA) AREA INUNDATED45,000 ACRES (18,220 HA) PRE-PROJECT YEAR 2003 YEAR 2003 FIRST PEAK2ND JULY, ,000 CFS (1,700 CMS) SECOND PEAK10TH JULY, ,000 CFS (1,700 CMS) THIRD PEAK14TH JULY, ,900 CFS (1,470 CMS) BREACHES5 No - Relief Cuts BREACHES5 No - Relief Cuts DISCHARGE AT CANAL CROSSINGS9,000 CFS DISCHARGE AT CANAL CROSSINGS9,000 CFS AREA INUNDATEDNOMINAL AREA INUNDATEDNOMINAL POST-PROJECT

PRE & POST-PROJECT ATTENUATION OF FLOOD PEAKS FOR KAHA HILL TORRENT PEAK AT DARRAHFLOOD PEAK AT HILL TORRENT CROSSINGS PRE-PROJECTPOST-PROJECT 40,00015, ,00023,0002,500 60,00031,0004,500 70,00039,0009,000 80,00048,00014,000 Discharge - CFS

CROPPING PATTERN AND INTENSITIES UNDER PRE AND POST PROJECT CONDITIONS CropsPre ProjectPost Project Cropped Area (HA)Intensity (%)Cropped Area (HA)Intensity (%) Kharif Sorghum1, , Bajra , Cotton00.01, K.Total2, , Rabi Wheat , Gram Oilseed , R.Total , Annual2, , CCA = 36,253 HA

PROPOSED AND ACTUALLY BENEFITED AREAS AGAINST VARIOUS PEAK FLOODS Crops Proposed at Feasibility LevelAchievement under Post Project Period Return Periods - Years Jawar9,76918,78823,34923,5957,21413,87417,24217,424 Bajra1,4892,8633,5593,5971,1002,1142,6282,656 Wheat1,7603,3864,2094,6991,3002,5013,1083,470 Gram5341,0281,2751, ,053 Oilseed7531,4461,8002, ,0681,3291,485 Total:14,30627,51234,19235,32810,56420,31625,25026,088 CCA = 36,253 HA

COMPARISON OF ECONOMIC INDICATORS Sr. No. ItemUnit Pre-Project in Feasibility Report 1990 Post-Project in Evaluation Report Financial Project CostRs. Million Balochistan WorksRs. Million Punjab WorksRs. Million Economic Project CostRs. Million Implementation PeriodYears35 4Project Annual BenefitsRs. Million Agriculture BenefitRs. Million Flood Damage SavingRs. Million Economic Parameters - Economic Interval Rate of ReturnPercent Benefit Cost Ratio at 10% DiscountRatio1.63:11.91:1 - Net Present Worth at 10% DiscountRs. Million

FUTURE STRUCTURAL IMPROVEMENTS A.PROP WALL CONSTRUCTED UNDER THE CREST ON D/S SHOULD BE PLACED UPSTREAM UPTO CREST LEVEL TO ENSURE Uniform flow Uniform flow Check washing of fines Check washing of fines Safety Against Scour Safety Against Scour B.ORDER OF CONSTRUCTION Construction must start from Darrah to down stream Construction must start from Darrah to down stream C.DEGREE OF PROTECTION Down stream works need more protection as compared to the upper ones Down stream works need more protection as compared to the upper ones D. STRCTURAL IMPROVEMENTS Upper end of Salai should be semi circular instead of rectangular Upper end of Salai should be semi circular instead of rectangular Terminal end should be similar to that of guide bund Terminal end should be similar to that of guide bund Off-take should be located >10 H above the cross structure Off-take should be located >10 H above the cross structure For H < 2 meter falls with glacis be adopted instead of drop falls For H < 2 meter falls with glacis be adopted instead of drop falls

COST OF STRUCTURAL INTERVENTIONS PUNJAB PROVINCE PUNJAB PROVINCE RS.MILLION SCENARIO - 1. WITHOUT DISPERSION STRUCTURES Cost of 40 Cross-Drainage Structures on Kachhi Canal RD: 0 – 990 (Punjab) 2,184 Cost for increasing Flood Carrying Capacity Against 40-Year Return Period on D.G.Khan Canal System: (a) Excluding cost of flood carrying channels (b) Including cost of flood carrying channels 813 1,194 Sub Total (a) Sub Total (b) 2,997 3,378 SCENARIO - 2. WITH DISPERSION STRUCTURES Dispersion Works in Pachad Area and Flood Carrying Channels RD: 0 – 990 1,363 Constructing Drainage works on Kachhi Canal Corresponding to Existing X-Drainage Structures on D.G.Khan Canal System Total BALOCHISTAN PROVINCE Cost of flood management for Nallahs Orignating from Marri Bughti Hills & Mountainous Regions upto Gandava/Badra Nallah 1,920 3,

FINDINGS & CONCLUSIONS Efficacy of existing cross-drainage structures on DG Khan & Dajal branch be evaluated. Efficacy of existing cross-drainage structures on DG Khan & Dajal branch be evaluated. Flood peak attenuation at cross-drainage structures through dispersion structures is significant. Flood peak attenuation at cross-drainage structures through dispersion structures is significant. Suggested improvement in the design of structural interventions be taken into account in future hill torrent projects. Suggested improvement in the design of structural interventions be taken into account in future hill torrent projects. In spite of shortcoming in design, diversion of flood flows in Pachad area has been reasonable during post-project environments. In spite of shortcoming in design, diversion of flood flows in Pachad area has been reasonable during post-project environments. Construction of dispersion structures in Pachad area is technically and socially more attractive than disposal of flows into Indus River. Construction of dispersion structures in Pachad area is technically and socially more attractive than disposal of flows into Indus River. Ensure the availability of funds for O&M at proper time. Ensure the availability of funds for O&M at proper time. Existing & future users of canal water on the right bank through lift pumps be duly considered for planning & design of Kachhi Canal. Existing & future users of canal water on the right bank through lift pumps be duly considered for planning & design of Kachhi Canal.

RECOMMENDATIONS Dispersion Structures in Pachad Area on Sori- Lund, Sakhi Sarwar,Vidore, Chachar, Zangi & Shori Janubi and Flood Carrying Channels in Command Area be constructed. Dispersion Structures in Pachad Area on Sori- Lund, Sakhi Sarwar,Vidore, Chachar, Zangi & Shori Janubi and Flood Carrying Channels in Command Area be constructed. Carrying Channels leading to Indus River for Pitock and Shori Shumali be constructed. Carrying Channels leading to Indus River for Pitock and Shori Shumali be constructed. Cross drainage Structures on Kachhi Canal be constructed as per D G Khan & Dajal Canal System. Cross drainage Structures on Kachhi Canal be constructed as per D G Khan & Dajal Canal System. Dispersion Structures would facilitate in the irrigation of additional area of about 80,000 HA. Dispersion Structures would facilitate in the irrigation of additional area of about 80,000 HA. Provision may be made for Channelization of water along the right-bank through embankments constructed water course crossing Pipelines. Provision may be made for Channelization of water along the right-bank through embankments constructed water course crossing Pipelines.

STUDIES PLANNED TO BE CARRIED OUT BY CONSULTANTS Frequency analysis of flood flows of nallahs/rivers at darrah(s) and at canal drainage structures. Frequency analysis of flood flows of nallahs/rivers at darrah(s) and at canal drainage structures. Study the adequacy of existing cross draining structures on DG khan system in the light of frequency analysis. Study the adequacy of existing cross draining structures on DG khan system in the light of frequency analysis. Remodeling of existing cross drainage structures if inadequate and additional structures if required on DG Khan canal / Dajal Branch. Remodeling of existing cross drainage structures if inadequate and additional structures if required on DG Khan canal / Dajal Branch. Consultants should advise for alternative strategies to irrigate Pachad area in lieu of proposed construction of 400 water course crossings on Kachhi Canal Consultants should advise for alternative strategies to irrigate Pachad area in lieu of proposed construction of 400 water course crossings on Kachhi Canal Consultants will probe that after construction of dispersion structures the flood peak will be reduced in accordance with the existing capacity of cross drainage structures on DG Khan system. Consultants will probe that after construction of dispersion structures the flood peak will be reduced in accordance with the existing capacity of cross drainage structures on DG Khan system. Consultancy proposal for flood management of hill torrents originating from Suleiman Range and Marri Bugti hills from Taunsa Barrage to tail of Kachhi Canal. Consultancy proposal for flood management of hill torrents originating from Suleiman Range and Marri Bugti hills from Taunsa Barrage to tail of Kachhi Canal. Revision of PC-I to accomodate hill torrent works in Punjab & Balochistan Provinces. Revision of PC-I to accomodate hill torrent works in Punjab & Balochistan Provinces.

THANKS