himal power limited project · hpl is continuing. the programme consists of all aspects of fish...

Environmental Monitoring Report

Project Number: 27707 November 2006

NEPAL: Himal Power Limited Project

Prepared by SWECO Groner AS Kathmandu, Nepal For Himal Power Limited

This report has been submitted to ADB by Himal Power Limited and is made publicly available in cordance with ADB’s public communications policy (2005). It does not necessarily reflect the views of

acADB.

Annual Environment Monitoring Report 2005-2006 (2062-63)

Khimti I Hydro Power Project

Issued by:

Himal Power Limited Bijaya Niwas, Jhamsikhel

Lalitpur, Nepal P.O. Box 12740

Kathmandu, Nepal

November 2006

Annual Environmental Monitoring Report 2005-06 Himal Power Limited

Page 1 of 17

TABLE OF CONTENTS PAGE

1 Executive Summary _________________________________________________ 2

2 Site Inspection _____________________________________________________ 2

3 Site report _________________________________________________________ 2

3.1 Headworks____________________________________________________ 2

3.2 Landslides at Koile (between Adit 1 and Adit 2) _____________________ 4

3.3 Adit 2 ________________________________________________________ 4

3.4 Adit 3 ________________________________________________________ 5

3.5 Adit 4 and Surge Shaft __________________________________________ 6

3.6 Adit 5 ________________________________________________________ 8

3.7 Kirne_________________________________________________________ 8

4 River Ecology Study Programme ______________________________________ 9

5 Jhankre Rural Electrification and Development Project (JREDP II) _________ 9

6 Environmental Mitigation ____________________________________________ 9 6.1 Khimti Khola Irrigation works ___________________________________ 8

6.2 Haluwa Khola Irrigation Project ________________________________ 10

6.3 Other Mitigation works _________________________________________ 9

7 Khimti Project School ______________________________________________ 13

8 Health and Safety__________________________________________________ 13

8.1 Accidents Statistics ____________________________________________ 13

8.2 Safety Issues__________________________________________________ 14

8.3 Safety Related Trainings _______________________________________ 14

8.4 Clinic Report _________________________________________________ 14

TABLES Table 1: Accidents Figures____________________________________________ 10 Table 2: Annual Work Related Accidents __________________________________11 Table 3: Annual Morbidity Data__________________________________________11 Annex A: Minimum Release Flow Record Annex B: Flow Measurement at Khimti River Annex C: River Ecology Study – Annual Report 2005


Page 2 of 17

Executive Summary The year 2005-2006 (2062-63) is the 6th Commercial Operation year of Khimti I Hydropower Plant. The operation of the power plant was smooth during this year. This year the monsoon has been a month late. A system for the monitoring of dry season minimum release flow from the diversion weir has been maintained well. Re-vegetation is satisfactory in all spoil tip areas and Headworks. Rural electrification in the project-affected areas carried out by Jhankre Rural Electrification and Development Project (JREDP) is going smooth. The JREDP project is almost completed and preparations are being made to handover the assets and systems developed in the project to the Khimti Rural Electric Cooperative (KREC) as planned. Regular monitoring of the landslide at Headworks and Koile is being carried out. Compensation payment to the landowners against the land slide at Koile has been completed. Environmental mitigation was carried out smoothly. The Haluwa Khola irrigating canal is running well for irrigating the Gogantar plateau. The relation with the local communities and the governmental bodies remained good. Site Inspection A site inspection of Headworks, Adit 1, Adit 2, Adit 3, Surge Shaft, Adit 4, Adit 5 and Kirne was carried out during 12-13 August 2006 to check the environmental compliance of the project. The inspection team consisted of Mr. Gyan B Karki (HSE Manager, HPL) with a civil worker. Similarly, the team had visited the site during the first week of the August 2006 to inspect the mitigation works such as irrigation, school, drinking water etc that was carried out during this year. Site report 3.1 Headworks/Adit 1 • Re-vegetation

After Royal Nepal Army was deployed at Headworks site Palati, some trees and bushes were cleared by them. However, the vegetation is grown up fully in the areas. Tree plantation is also carried out this year in some areas to the north of the Basin. The re-vegetation at Headworks and Adit 1 is satisfactory.

• Landslides

The gabion structure seems stable. We have established 10 monitoring points at the hill side of the basin at different locations on the main gabion structure and on rocks. The movement of the slide is being monitored regularly. There is no observed movement of the area. However, there was a small land slide at the left bank at 300 m downstream of the weir during the monsoon flood. No new landslides took place at the Headworks area this year. The vegetation is well grown in the area.


Page 3 of 17

• Palati Khola

No problems were encountered associated with Palati Khola regarding the operation of the plant during the reported period.

• Trash Rack Debris

The trash such as twigs and leaves are buried in a pit and after decomposition that will be used as a fertilizer for the plants. Big logs collected are stacked to dry in the open air and they are either used by the project or sold to the local villagers at nominal prices. These are also used by locals for cremating purpose (for burning the dead body).

• Minimum Release Flow The minimum release flow through the fish passage at the Diversion Weir was maintained at more than 500 lps throughout the Dry season. The Fish Passage is functioning properly. In the beginning of every Dry season, the fish passage is repaired for damages during the flood season. Observations were made by the HPL operators twice a day throughout the Dry season and logs are kept properly (pelase refer Annex A). The residual flow from the weir was verified by a hydrologist from Butwal Power Company, an engineering consulting firm from Nepal, during their visit on 1-4 May 2006 (please refer Annex B). The verification confirmed that HPL was releasing the minimum flow above the requirement.

Pic 1: Headworks - vegetation at the north side of the de-silting basin


Page 4 of 17

Pic 2: Headworks - vegetation at the right side of de-silting basin 3.2 Landslides at Koile (between Adit 1 and Adit 2) Koile landslide has stabilised better this year than last year. Some vegetation has grown up in the areas. As the compensation is paid to the land owners, they have stopped cultivating the land. Some HDPE pipes are laid on the surface to divert the spring water out from the problematic area. Regular inspection and Maintenance works for the surface drain is being done during monsoon. A local man is hired to regularly monitor the landslide especially for the rainy season. However, some leakages and heavy rainfall during the rainy season has developed some additional cracks in the area. 3.3 Adit 2 • Slope stability

In the previous year, some superficial cracks were developed on the top surface of the spoil tips as a result of settlement of the muck. This crack also had made some damages on the surface drainage constructed at the hill toe above the spoil tip. The drains are repaired and


Page 5 of 17

the cracks were filled up in the past years. This year, no cracks are observed in the area and it appears more stabilised as more vegetation has grown up.

• Re-vegetation

The re-vegetation is fully developed and has grown up to dense. A local guard has been hired for the protection of re-vegetation from the grazing of the cattle and from the cutting of grass. In the potential entry points of the cattle bamboo fencing has been installed.

Pic 3: Vegetation growth at the Koile landslide area

3.4 Adit 3 • Slope stability

There is not further development in the superficial cracks that were observed in past years. However, some gabion structures at the toe of the slope have been tilted because of the stream that eroded the foundation of the gabion support. It is being regularly monitored. No remedial measure is carried out.


Page 6 of 17

• Re-vegetation

The re-vegetation has grown up to dense. Guarding the area by locals was continued throughout the year for the protection of re-vegetation from the grazing of cattle and from the cutting of grass.

Pic 4: Adit 3 spoil tips area covered by grown up vegetation 3.5 Adit 4 and Surge Shaft • Slope stability

There is not any development in the superficial cracks and the slope seems to be stabilised. • Re-vegetation

The re-vegetation at Surge Shaft area is good but needs to be improved at Adit 4 spoil tip area. Some grass and trees plantation works are carried out during the monsoon of the last year. A local guard has been hired for each Adit 4 and Surge Shaft area for the protection of re-vegetation from grazing of the cattle and from cutting of grass. In the potential entry points of the cattle, bamboo fencing has been installed. The trees are fully grown in the surge shaft area.


Page 7 of 17

Pic 5: Vegetation at Adit 4 spoil tips area

Pic 6: Growing pine tress in surge-shaft area


Page 8 of 17

3.6 Adit 5 • Access Road

There were small land slides at the access road to the portal at one location which has been cleared out. The road drains filled up with the debris and soil is cleaned. The road is not in good condition; however it can be made usable when needed with small maintenance.

• Re-vegetation

The spoil tip area looks stable. The re-vegetation is gradually improving. Some plantation work was carried out in the last year and is being developed.

Pic7: Adit 5 spoil tip re-vegetation

3.7 Kirne • Re-vegetation

There was a rock crusher plant installed at Bhorle area for producing the materials for the blacktopping of the road carried out by Himal Power Limited in and around the camp area at site. Due to this reason, the vegetation is not properly grown up this area. There is plan


Page 9 of 17

of developing this area by landscaping in the next year and necessary re-vegetation will be carried out. The quarrying of sand is stopped from this area. The vegetation in the other areas at Kirne looks satisfactory.

• Rescue Boat in the Powerhouse A special rescue boat which suits the conditions in the tailrace is installed and tested with human rides at full power generation during its installation two years before. The boat is ready and standby for the purpose of emergency evacuation from the powerhouse.

4. River Ecology Study Programme Fish Monitoring was renamed as River Ecology Study Programme to cover broader aspects of impacts of Khimti I Hydropower Project to the river ecology of Khimti River. River Ecology Study Programme at Khimti River; agreed by Independent Engineer, Government of Nepal and HPL is continuing. The programme consists of all aspects of fish monitoring and a study on the impacts of fishermen. HPL is carrying out Fish Monitoring works since June 2000. This project was started just after operation period. From 2000, Statkraft Groner (now Sweco Groner) was employed together with BPC for fish monitoring. Three fishing stations were identified and a permanent local fish biologist was kept at site whereas the expert from Sweco Groner came once each year for electro fishing in these stations. A complete River Ecology – Annual Report 2005 is attached in Annex C of this report. 5. Jhankre Rural Electrification and Development Project (JREDP II) All 4300 households are electrified as planned. The Jhankre mini-hydro power plant is in the final phase of testing and commissioning. Khimti Rural Electric Cooperative; the legal entity to takeover all assets and systems developed during JREDP II; is now in the final phase of takeover which is planned for December 2006. 6. Environmental Mitigation 6.1 Khimti Khola Irrigation Works The mitigation works were continued this year also where the project has some direct effects on the irrigation. Special attention is given to maintain the irrigation canals which lie downstream of the Diversion Weir. As a result of the big floods in Khimti in the last year in 2004, the Intake structures of some canals were damaged. So the intake structures for these canals were repaired. Similarly the old canals were repaired at different location as mentioned below.


Page 10 of 17

The following canals were repaired and upgraded this year: 1. Canal at Maranghat, Pharpu VDC, Ramechhap District 2. Canal at Okhle, Pharpu VDC, Ramechhap District 3. Canal at Kaseri, Sahare VDC, Dolakha District 4. Canal below Gobantar, Kainjare (Ofara) Sahare VDC, Dolakha District 5. Canal at Devisthan Ghumaune Khet, Shahare VDC, Dolakha District 6.2 Haluwa Khola Irrigation Project Haluwa Khola irrigation system is providing 55 lps of .water to Gogantar plateau with a command area of 30 hectares that has been completed in 2002 (2059 BS). The project was handed over to users committee on 2059/8/9 BS. Operation and maintenance guidelines for the project also have been handed over to the users committee. Now water is flowing from the Haluwa Khola to the Gogantar through the irrigation system. Although the system is already handed over to the locals, HPL is regularly monitoring and making correspondence to the users committee whether they are systematically operating the system or not. The system is running well. 6.3 Other Mitigation Works Nayapul-Kirne road side community support HPL has supported for drinking water and toilet construction for Narayani secondary schools in Bhirkot and Ajadi Primary School Melung which lie close to the Nayapul - Kirne road. Similarly, Milti Irrigation canal which was taken down by land slide was reconstructed by using Hume pipe for about 150 m length. When the canal was reconstructed, about 100 households of farmers re-started the irrigation. Although the area does not lie within the affected area, the strategy was taken to support the schools to have positive feedback and supports from the locals while HPL staff travelling through this road. Irrigation and Drinking water supports at local communities In Shahare VDC, a 400 metre long canal (concrete lined) was constructed in the year 2002 and it was extended more than 210 metres in year 2004. The irrigation canal was constructed because the source of irrigation was dried in the area after the headrace excavation of headrace tunnel. Still, there was request for constructing the canal called Lower Kalleri which was 600 m long. The needs was analysed and this year it was constructed and concrete lined for 250 meter length. Also US$4,000 was supported for purchasing the pipe for the Shaharetar Irrigation.


Page 11 of 17

Pic 8: Lower Kalleri Irrigation A 180 meter long concrete lined Irrigation canal has been constructed at Jhankre Minihydro Plant Area which is called Baseri Irrigation. These works were carried out to improve the earthen canal as per the demand from the locals to control the losses and to get a sufficient supply of water for farming. School supports at local communities HPL have supported many other primary and lower secondary schools for upgrading the existing school building and infrastructure in the affected area and some outside too. Two class room buildings have been constructed for upgrading of Trikuteshwar community school at Kirnetar and Kalika Primary school, Shahare in Bhageri VDC. Similarly a four class-roomed building was constructed to upgrade the Mahendra Secondary School, Chyama from primary to secondary level and a school building was upgraded by plastering the wall of Kalika sec. School Hamba. Also, it was supported for construction of drinking water for Jyamkiri Primary School, Phurpu VDC.


Page 12 of 17

Pic 9: Mahendra Secondary School, Chyama under construction Betali-Khimti Road Support: A gravel road is being constructed from Betali VDC to join Khimti Bazar (about 3 Km away form the plant station, Kirne) in the initiation of local VDCs of affected areas. The length of the road is about 18 KM. After the road is constructed, it will be a short way to drive to Headworks site Palati and also it will be very useful for the locals for transportation. Initial opening of road-track is 80% completed The Users Committee has requested for the financial support and HPL has helped by providing USD 15,000 in this year. The Users Committee has collected funds from government and from other sources.


Page 13 of 17

Pic 10: Betali-Khimti Road section 7.0 Khimti Project School / Clinic The project continues to run Khimti Project School with a good quality standard. This year the school is upgraded to class 9. It has a target of upgrading it to complete the secondary education. The project has been providing one teacher each to each of the community schools at Kirne, Bhotechhap ( Shahare) and Betali. 8.0 Health and Safety 8.1 Accidents Statistics There were a total number of 61 minor accident cases and no major and fatal accidents occurred during the year. However, there were three accidents causing absence from work. The annual work related accidents in quarterly basis defined as H1, H2,F is tabulated as below. H1 = Accidents with absence from work x 1 mill / total worked hours H2 = Accidents with and with out absence from work x 1 mill / total worked hours F = Days of absence due to accidents x 1 mill / total worked hours


Page 14 of 17

Table 1: Accidents Figures Items 1. Quarter

(2061/2062) 2. Quarter (2061/2062)

3. Quarter (2061/2062)

4. Quarter (2061/2062)

Average (2061/2062)

H1 21 0 0 1.2 8 H2 302 77 148 16 136 F 43 0 0 35 20

Table 2: Annual Work Related Accidents Minor Major Fatal Review case Total 61 0 0 23 83

8.2 Safety Issues The Management is constantly monitoring the use of Personal Protective Equipments (PPEs). The use of PPEs is made compulsory and there are no violations on use. 8.3 Safety Related Trainings Fire fighting and First Aid training were conducted during the year at both Kirne and Headworks site as per the requirement for the selected HPL staff.

8.4 Clinic Report There is a modest clinic run by the project at Kirne and Headworks site Palati. The Clinic treats the project staff as well as the local villagers. The clinic information is as tabulated below. 8.4.1 Morbidity Data on Monthly basis. Table 3: Annual Morbidity Data

No. Of Patients S.N Month Staff * NA ** Villager Total

1 Shrawan 311 117 869 12972 Bhadra 340 176 768 12843 Ashwin 318 108 690 11164 Kartik 192 116 706 10145 Marg 369 183 916 14686 Paush 230 91 778 10997 Magh 325 76 823 12248 Phalgun 255 77 898 12309 Chaitra 329 93 1158 158010 Baishakh 184 79 833 109611 Jestha 316 88 1312 171612 Ashad 242 77 1160 1479Total 3411 1281 10911 15603

* Staff means the staff of HPL and KSPL and daily wage workers and their dependents. ** NA means the soldiers of Nepalese Army at Headworks site Palati and Power Plant site Kirne.


Page 15 of 17

8.4.2 Data of MCH Clinic Total Antenatal Case Delivery in clinic

Male Baby

Female Baby

Still Birth

Retained Placenta/ PV Bleeding

Total 350

10 9 1 7 27

8.4.3 Data of Contraceptives Users: Table 5 Oral Pills Depo-Provera Norplant IUD Condoms 60 107 16 0 Not registered

8.4.4 Data of Dental Clinic: There were 475 persons treated in Dental clinic. Most of cases are of dental extractions.

8.4.5 Data of Laboratory Test :

Stool R/E Urine R/E Blood Semen

Analysis Pregnancy Sputum Total

390 489 77 3 227 111 1297 8.4.6 Most common diseases

Gastrointestinal system Skin Respiratory System

Genitourinary System

Others

25% 20% 15% 20% 20% Note: not specific Data, it is only assumption. 8.4.7 Data of DOTS Program of T.B Patients:

8.4.8 Data of Tuberculosis Cases

Test of Sputum For Diagnosis of T.B.

Test of Sputum for follow up Total Slide examined

Positive Case Negative Case Total Positive Negative Total 6 96 102 1 8 9 111

Pulmonary Case

Extra pulmonary

Case

Total Case

Treatment From Clinic

Under Rx

Cured/Completed

from clinic

Defaulter case/ Death

1 1 2 2 1 1 0


Page 16 of 17

8.4.9 Training/Seminars and others: • Two staff from the clinic attended the DOTS trimester Seminar organised at DHO,

Charikot and one staff attended the DOTS Plus symposium training at NTC Bhaktapur. • A Family Planning Camp was organized jointly with the government one time during the

year at Kirne. • Dental & MCH clinic is organised every Wednesday • Health Education Programs is conducted from time to time and World Aids & World

Environment day is celebrated to inform the staff and the locals • 24 hrs emergency clinic services are provided with standby Ambulance service. • A Medical care fund is established for helping very poor patients. • 53 cases reported in the Kirne clinic during the year, which were beyond the facility in

the Kirne Clinic for treatment, were referred to other hospitals.

9.0 Special Issues Related to Health and Safety 9.1 Rescue Boat in the Powerhouse A special rescue boat (similar quality as used in the North Sea) which suits the conditions in the tailrace is installed and tested several times. All staff in operation & maintenance division that visit/work in the power house on a regular basis have carried out a full test ride all the way out of the tailrace. The boat is furnished with a fixed illumination system based on battery connected to a charger when the boat is in stand-by mode. 9.2 Fire fighting and Breathing apparatus training Fire fighting and breathing apparatus training has normally been conducted twice a year. The training includes practices as well as theoretical classes. Practical courses include practice with water and hoses, fire drill, using of different kinds of fire extinguishers, donning and start-up, walk-run-climb exercise and personal rescue techniques & room searching for casualty handling. Normally practical course is given to fire fighting team. However, theoretical classes on fire safety; demonstration and practice of using fire extinguishers and fire blankets are given to the maximum number of staff including all operation and maintenance staff. During the practice, inspection of fire extinguishers, testing of smoke and heat sensors and fire alarms placed in various locations of the plant were also carried out. Details of trainings conducted in FY 2062-63 (2005-6): Kirne (powerhouse): 27th December 2005 6th Nov 2006 (planned) Headworks: 20th August 2005 6th Nov 2006 (planned) Fire drill: One fire drill was conducted on 21st July 2006 due to the fire in one of the residential quarter at powerhouse site at Kirne. Suddenly fire occurred in the quarter around 9’o clock in the evening. Residing person was on vacation at that time. Fire fighting team managed to control the


Page 17 of 17

fire within an hour with the help of fire extinguishers and water hoses. Goods, furniture and equipments worth around US$3,000 were damaged. There were no other damages or casualties. 9.3 First-Aid Trainings First aid drills conducted last year: Total 58 cases (most of the cases are related to cut injuries, lacerated wounds, foreign body in eyes, stabbed wounds etc.) 9.4 Protection against Noise-Pollution No noise monitoring system is installed in the power house, however, while working in the power house, air defender or ear plugs are used and similar protection equipment is used while working in workshop during grinding cutting etc. These ear-plugs were as recommended by the equipment supplier. Office Vehicles moving around the project site normally does not make excessive noise and for the public vehicles moving on the main road, the drivers are informed through guards and security check-post not to use the horns while driving through the residential and clinic area. 9.5 High Voltage Protection System and Protection against Electrocution Detailed standing procedures are made for high-voltage working. A Norwegian Electrical Manager is responsible for authorizing such work. There are set protocols for working on the HV system. These rules are very strictly followed and there has been no incidence. In the case such accident occurs, accident reporting system and rescue procedure; that has been prepared immediately after the operation started; is used. 10. Environmental Management Since July 2004, a full time Health Safety and Environment Manager (HSEM) is assigned for the environmental mitigation and monitoring works. He is a qualified civil engineer with experience in environmental related issues.

Annex A

Minimum Release Measurement Log sheet

HPL ftan (1' ~ TC4~ f(.it1rc!6Himal Power limited

Khimti 1 Hydropower Plant,Dry season release flow measurement log sheet,Headworks.

Remarks: ... ... ... ... ... ... ..........

..,..................................

................................................................

1 Rainfall:

" 2 Flood

"" '--'--iUFa'tron(from/to}.. . .... .. ... ... ....... .. ...~. ~

p61yes,dur;on (from/to) .. .. ... ... .

~,~,~...-

..

v-..

It is responsibility of duty op~rators toJilUhis log sheet. l' ~

Required depth of water in the notch for 500 lis discharge is 2~ CM

Depth of water shouldn:o)-,-~~,I~$!}hjm required. 'u n~

. ~ ... . -'--.=..~..._.

Duty operators are responsi~~iOtarn the required depthwith the hJp7;fcivi

Note:

.'-~" ..'.

-

This log sheet should send to HaM by each mail.

Incharge HW

Depth of water in Water level Water levelDate Time the notch CM River Intake Power MW Recorded by Remarks

j..Dh ,..1)1- C) 1 :30 L-f>'S .12-"':(-1-go 12.. j '"'14- 1' 4. v'""Y

45:30 I 2-V- { . oG I 2-';1-1'12- 10 >-0 ..,. .--:y

Annex B

Minimum Release Flow Measurement Report by Butwal Power Company (BPC)

June 2006

Himal Power Limited (HPL)

Khimti Khola Fish Monitoring Flow Measurement June 2006 Jestha 2063

BPC Hydroconsult

Kathmandu, Nepal

Himal Power Limited (HPL)

Khimti Khola Fish Monitoring Flow Measurement

Quality control Signature DatePrepared by: Dilli Choudhary Checked by: Rita Chitrakar Approved by: Padam Pokhrel

June 2006 Jestha 2063

BPC Hydroconsult Butwal Power Company Ltd. Buddhanagar, Kathmandu PO Box 11728 Kathmandu, Nepal Phone: (01) 4781776, 4785295 Facsimile: (01) 4780994 E-mail: [email protected]

BPC Khimti Khola Fish Monitoring Project

F:\Data\PDM\Annual Report\2062-63\AMR\Annex B_MinimumRelease_Flow measurement Report June 06.doc Page 1 of 2

TABLE OF CONTENTS Page no.

TABLE OF CONTENTS...........................................................................................................1

1. BACKGROUND ................................................................................................................2 1.1 Introduction .................................................................................................................2 1.2 Flow measurement and site selection for gauge station .............................................2

1.2.1 Location-1, Weir .............................................................................................................. 2 1.2.2 Location-2, Just D/S of Haluwa Khola ............................................................................. 2 1.2.3 Location-3, Near the confluence of Khimti and Tama Koshi ............................................ 2

BPC Khimti Khola Fish Monitoring Project

F:\Data\PDM\Annual Report\2062-63\AMR\Annex B_MinimumRelease_Flow measurement Report June 06.doc Page 2 of 2

1. BACKGROUND

1.1 Introduction Butwal Power Company Limited has been involved in Fish monitoring on Khimti Khola for the last five years in close consultation with Sweco Groner. This time the discharge has been measured at gauging and pressure sensor stations only. The corresponding discharges and stage height have been measured. The two different methods have been used to measure the flow i.e. current meter where there are defined and uniform cross sections and salt dilution method where there are turbulent flows, rapids and not uniform cross sections. This time site visit was conducted from 1st May 2006 to 4th of May 2006. Civil Engineer (Hydrologist) Mr. Dilli Bahadur Choudhary was involved in the field visit.

1.2 Flow measurement and site selection for gauge station Flows were measured at the locations identified by the Specialist from Sweco Groner. Measured site locations and discharges are shown in Figure 1.

1.2.1 Location-1, Weir

At headworks, on the weir Himal Power Limited (HPL) has constructed the rectangular weir having the weir width 2.0 m to measure the flow. Two sets of measurements were taken using current metre on the weir having the water depth 28.5 cm and average discharge was found to be 0.536 m3/sec, which is 36 liter higher than required for downstream release. Therefore, it is recommended that the water depth on weir crest should be maintained 28.0 cm to provide D/S release of 0.5 m3/sec.

Gauge height was 18.5 cm during the flow measurement at headworks.

1.2.2 Location-2, Just D/S of Haluwa Khola

At Just downstream of Khimti- Haluwa Khola confluence there is a gauging and pressure gauging station. Two sets of flow was measured just downstream of Haluwa Khimti confluence location using salt dilution method. The average flow was found 0.8 m3/sec and corresponding gauge height was 82.0 cm.

1.2.3 Location-3, Near the confluence of Khimti and Tama Koshi

There is existing fish monitoring station near confluence of Khimti Khola and Tama Koshi River. Two sets of discharge have been measured just upstream of gauging station and pressure sensor using the salt dilution method when the power plant was in operation mode. The average flow was found 0.92 m3/sec and corresponding gauge height was 18.0cm.

Annex C

River Ecology Annual Report 2005-06 by Sweco Groner

SWECO GRØNER

SWECO GRØNER Postboks 400 NO-1327 LYSAKER Norway Telephone: +47-67128000 Fax: +47-67125840

SWECO Grøner AS Reg. No.: NO-967 032 271 MVA Member of the SWECO group www.sweco.no e-mail: [email protected]

REPORT Report no.: Commission no.: Date: 133172-R03 133172 13.03.2006 Commission name: KHIMTI KHOLA HYDROPOWER PROJECT

Customer: Himal Power Ltd. (HPL), Nepal

KHIMTI KHOLA HYDROPOWER PROJECT RIVER ECOLOGY - ANNUAL REPORT 2005

Subject word:

Khimti Khola Hydropower Project, Nepal, river ecology, monitoring programme, water quality, catch per unit effort, cast nets, electrofishing.

Summary:

This is the fourth annual report of the six-year monitoring programme for the Khimti Khola Hydropower Project in Nepal. The objective is to monitor the long-term response of fish populations to the implementation of the hydropower plant. Fish sampling was performed using the same methods and at the same locations as previously.

River water quality was sampled and analysed in January and July 2005.

Whilst Asala or spotted mountain trout dominate, Katle or copper mahseer and titae or stone carp are also important fish species. More species were observed using the electrofishing method than by use of cast nets. Electrofishing results indicated an increased juvenile fish density at Rasnalu and upstream Palati. The density downstream of Palati is stable low, with an increase in older fish density. Electrofishing results also indicated an overall increased fish density over the last two to three years.

The average combined catch per unit effort value (CPUE) for all fish sampled was 0.09 per cast for the 2004/2005 season, which is a little higer than the previous year.

Downstream of the Palati intake weir lower CPUE values were recorded than upstream (0.16 versus 0.10).

Rev.: Date: Sign.: Written by: Halvard Kaasa, Finn Gravem, Håkon Gregersen, David Wright 13.03.2006 HG, FRG Verified by: David A. Wright 03.03.2006 DAW Executive in Charge: Project manager / dep.:

Tore Hagen Halvard Kaasa


SWECO Grøner AS Page 2 of 59

CONTENT SUMMARY........................................................................................................................................ 3 1 INTRODUCTION........................................................................................................................ 5 2 KHIMTI KHOLA HYDROPOWER PROJECT ........................................................................... 6

2.1 THE PROJECT.................................................................................................................................... 6 2.2 SAMPLING STATIONS – WATER QUALITY ............................................................................................... 7 2.3 SAMPLING STATIONS - FISH ................................................................................................................ 7 2.4 HYDROLOGY ................................................................................................................................... 12

2.4.1 Water temperature ................................................................................................................ 12 2.4.2 Water Level Measurements................................................................................................... 14 2.4.3 Discharge Measurements...................................................................................................... 17 2.4.4 River flow Conditions............................................................................................................. 19

2.5 RIVER ECOLOGY ............................................................................................................................. 20 3 METHODOLOGY..................................................................................................................... 23

3.1 WATER QUALITY.............................................................................................................................. 23 3.2 ELECTROFISHING ............................................................................................................................ 24 3.3 CAST NETS ..................................................................................................................................... 24

4 RESULTS ................................................................................................................................ 26 4.1 WATER QUALITY.............................................................................................................................. 26 4.2 ELECTROFISHING ............................................................................................................................ 27 4.3 LONG TERM DEVELOPMENT ............................................................................................................. 38

4.3.1 Rasnalu ................................................................................................................................. 38 4.3.2 Palati Upstream..................................................................................................................... 38 4.3.3 Palati downstream................................................................................................................. 39 4.3.4 Banchare............................................................................................................................... 40 4.3.5 Gobantar ............................................................................................................................... 40 4.3.6 Khimti Besi ............................................................................................................................ 41

4.4 CAST NETS ..................................................................................................................................... 42 4.4.1 Rasnalu ................................................................................................................................. 42 4.4.2 Palati Upstream..................................................................................................................... 43 4.4.3 Palati downstream................................................................................................................. 45 4.4.4 Banchare............................................................................................................................... 46 4.4.5 Gobantar ............................................................................................................................... 47 4.4.6 Khimti Besi ............................................................................................................................ 49 4.4.7 Diurnal variation .................................................................................................................... 51

5 ANALYSIS AND DISCUSSION............................................................................................... 53 6 CONCLUSIONS....................................................................................................................... 58 7 REFERENCES......................................................................................................................... 59 ANNEX .........................................................................................................Terms of reference



SUMMARY

This is the fourth annual report of the six-year monitoring programme for the Khimti Khola Hydropower Project in Nepal. The objective is to monitor the response of fish populations to the implementation of the hydropower plant. This is achieved by collecting data to determine if the hydropower scheme causes impacts on the fish populations in Khimti Khola.

In addition to presenting the results from the monitoring programme for the period June 2004 to May 2005, this report also reviews some of the results from previous years to form a basis for evaluation of the trends.

Due to security reasons fieldwork was at times restricted during previous years. In April 2003, however, the sampling programme was extended with two stations: Banchare and Khimti Besi. In March 2004 and in 2005 electrofishing was carried out at all six stations. Data from the six stations also provides a better basis to understand and evaluate the effect of reduced river wet periphery during the low flow season.

New water quality analysis from January and July 2005 is presented. New hydrological data from 2005 is also included; the data is, however, sparse because of data lost due to the theft of the flow measurement instruments. There are no hydrological data from the periode before 2005.

This report also presents the latest results from, cast net fishing as CPUE values, and fish densities as results from the electrofishing.

For the current report, fish sampling was performed using the same methods and at the same locations as previously. The fish sampling methods used are the same as in the Feasibility Study and in the IFC Supplementary Environmental Assessment, reported in 1994 and in later fish studies. The cast net fishing was performed during both the high and low flow periods, while electrofishing was done during low flows once a year only, aiming at including data from the juvenile part of the fish community.

Asala, or spotted mountain trout (Schizothorax plagiostomus) dominated at all stations and in both methods. Katle, or copper mahseer, (Acrossocheilus hexagonolepis) and titae, or stone carp (Psilorhynchus pseudecheneis) are also important fish species. Tvelve fish species were registered during the 2004-2005 season. Altogether 15 species have been caught since the start of the programme. The three species missing are, however, low density species and catching them is thus more difficult.

More species were observed by electrofishing than by use of cast nets. The electrofishing results indicate an increased density at most of the stations. At some stations such as downstream of Palati, however, there was a low recruitement in 2005.

The average combined CPUE for all fish species and for all sampling stations was 0.09 per cast for the 2004-2005 season. The results from the 2000-2001 and 2003-2004 study showed an average CPUE of 0.09 and 0.08 fish per cast respectively. For the two intermediate seasons the CPUE value was 0.11 fish per cast with all data. The results may thus indicate a decline in population.

In the seasons previous to this year’s programme the cast net results at Palati have shown significant differences since power plant implementation, with higher CPUE values at the upstream station than at the downstream one. This picture was also enforced by the results from the 2005 electrofishing campaign.

It seams evident that the monthly catches at Palati downstream follow a pattern similar to the monsoon cycle, with more fish caught at high water discharges, and with hardly any catch from December to February. One important difference between these two stations is the flow conditions



during the low flow season due to hydropower regulation. The station at Palati downstream has also been fenced and thus protected from fishing and the use of poison.

For the 2000-2001 season the overall CPUE value was almost the same at Palati downstream and at Rasnalu, the control station. During subsequent seasons the values were considerably higher at Palati downstream than at Rasnalu, the last seasons results being close to two times higher.

The cast net results at Gobantar showed a diurnal variation with a significantly better fish catch in the evening than in the morning, even after changing the hours of cast net operation in the evening.

Reports from the local consultant, BPC, and from fishermen along the Khimti river tell that fishing by diverting the river and adding poison is far more common now than before implementation of the hydropower plant. The use of poison has increased dramatically during recent years, since it has become easier to divert the river with a lower regulated flow than under natural low flow conditions.

The relatively stable CPUE values recorded by cast net fishing and the stable fish length frequencies from the electrofishing catches, together with an increased catch mortality during the low flow season, could indicate that during the monsoon the river is migrated by fish from downstream areas. Even if the Khimti Khola is physically changed due to hydropower regulation, it is so far not easy to see the overall alterations in the fish population that could be expected. Nevertheless, there are some changes in the records that might be a result of the hydromorphological changes. The coming studies, according to the ToR, will provide longer data series, and thereby give a better basis to evaluate the impacts of the hydropower scheme. There is also a need for better understanding of to which degree the river (and the stations) are affected by fishing with poison.



1 INTRODUCTION

This report is written on request from Himal Power Limited (HPL), and is the 4th. annual report in a six-year sequence. The international consultant, SWECO Grøner AS (previously named Statkraft Grøner AS before 2004), has had the scientific supervision of the local consultant, Butwal Power Company (BPC), which has been responsible for carrying out the cast net fishing from August 2003 to May 2005 and has kept the field journals. SWECO Grøner AS, with assistance from BPC, carried out the electrofishing in March 2005. The practical arrangements for the fieldwork, with transport and accommodation, were arranged by HPL. SWECO Grøner AS has analyzed the primary data. The reported activity is a part of the HPL River Ecology Programme, as described in the Terms of Reference (ToR, see annex). The IFC report from 1994 provides the baseline data of electrofishing results before the hydropower station was implemented. As per the Terms of Reference (annex) the next years will bring more data to highlight the environmental impact discussion.

Figure 1 Asala, or spotted mountain trout

(Schizothorax plagiostomus) is an important protein source, and is considered a delicacy, raw or cooked.



2 KHIMTI KHOLA HYDROPOWER PROJECT

2.1 The project The Khimti Khola Hydropower Project and its catchment is described in the supplementary EIA report (IFC 1994). The Khimti I Hydropower Project is a ‘Run-of-the-River’ type of hydroelectric plant with an installed capacity of 60 MW. The project is located in central Nepal, about 100 km east of Kathmandu. The power plant has been in operation since July 2000. At Palati there is a weir with an intake structure for the power plant (Figure 2). The headrace tunnel is about 10 km long and the affected part of the river is between 11 and 12 km in length. The tailwater from the power station flows into a larger river, the Tama Koshi, just upstream of the confluence with Khimti Khola. Khimti Khola has thus a reduced water flow from downstream of Palati to the confluence with Tama Koshi. A map of the area is shown in Figure 3. Tama Koshi is one of seven tributaries of the Koshi, which is one of three main river systems in Nepal. The two others are Gandaki and Karnali. The three river systems drain into the Ganges system in India. As much as 71% of the dry season flow in the Ganges may come from Nepal (Abbas 1982). Koshi is the largest river in Nepal and the largest tributary of the Ganges (Rajbanshi 2002).

Figure 2 The intake site at Palati. The weir across the river is in the middle of the picture.

The fish migration depression is on the right side of the weir. Photo: Halvard Kaasa.



Figure 3 Khimti Khola between the confluence with Tama Koshi and the Palati area.

Fish sampling stations are indicated in red. Water quality stations (A1 – A4) are indicated in blue.

2.2 Sampling stations – water quality Samples for water quality analysis have been taken from four stations at Khimti Khola: A1 - Upstream of Palati. A2 - 1 km downstream of Palati. A3 - Upstream of confluence with Haluwa Khola. A4 - Khimti Besi. This sampling started in 2004.

2.3 Sampling stations - fish The registration work started in 1994 at three localities. Palati was later split into two localities; upstream and downstream of the intake. As proposed by the Independent Engineer (Garcia and Associates 2002) two more stations were established in 2003 to benefit the River Ecology Programme by providing more detailed data, enabling a better description of the gradient in Khimti Khola from Palati and downstream to the confluence with Tama Koshi. Data from the six stations will also provide a better basis to understand and evaluate the effect of reduced wet periphery during the low flow season.



• Rasnalu. Situated about 15.5 km upstream of the confluence between Khimti Khola and Tama Koshi, at an altitude of 1570 m above sea level. This is about 4.5 km upstream of the intake structure at Palati. The river between Rasnalu and Palati has partly a steep gradient. The river bottom is composed of stones and boulders with an increasing percentage of smaller stones when entering the pool area (Figure 4). During winter the air temperatures could reach below freezing.

• Palati upstream. This is the area where the intake structure for water to the hydropower plant is situated. The sampling station used in 1994 was the same as used in later years, and the area is located upstream of the intake weir at about 1260 m above sea level. The flow at this station is not affected by the hydropower regulation (Figure 6). The substratum is mainly composed of stones and boulders, with some sand in small backwater areas.

• Palati downstream. When the hydropower scheme started its operation a sampling station was established only a few hundred metres downstream of the intake site. This area close to the intake weir is the most affected when it comes to the changes in river flow (Figure 7). It is located at about 1230 m above sea level. The river bottom is composed of boulders, stones and with some sand in small areas. This station has been fenced and thus protected from fishing and use of poison.

• Banchare. This station, which was included in 2003, is situated between Palati and Gobantar, and the river valley is narrow and the gradient steep. The substrate is mainly composed of large boulders with some fine sand between the boulders (Figure 8). The station is situated about 1000 m above sea level. Downstream of this station there is a vertical waterfall of more than 4 m drop.

• Gobantar. This station (Figure 9) is situated close to the village of Gobantar and in the lower region of the river where the valley is wider. The gradient is not so steep and the river alternates between pools and riffles. The elevation is about 700 m above sea level. The substrate differs between boulders, stones and sand, but with more sand than at the stations further up in the river. It is an area with noticeably higher temperatures than further up in the river valley.

• Khimti Besi. This station was also included in 2003, and it is located close to the village of Khimti Besi, about 600 m above sea level, and only a few hundred metres from the confluence with Tama Koshi (Figure 10). It is an open area, and the river changes between pools and riffles. The sampling station is composed of riffles and minor pools, and is situated downstream of a large pool. The substratum is composed of large boulders, stones and small gravel, with sand in small pockets between the boulders. The ambient temperature of the area is hot.



Figure 4 Khimti Khola at Rasnalu, upstream of the power plant site at Palati, April 2004. Photo: Halvard Kaasa.

Figure 5 Khimti Khola at Rasnalu, aerial view, April 2004. Photo: Halvard Kaasa.



Figure 6 Khimti Khola at Palati upstream, April 2003. Photo: Halvard Kaasa.

Figure 7 Khimti Khola at Palati downstream, April 2003. Photo: Halvard Kaasa



Figure 8 Khimti Khola at Banchare, downstream of the power plant site at Palati, April 2003.

Photo: Halvard Kaasa.

Figure 9 Khimti Khola at Gobantar, downstream of the power plant site at Palati, April 2003.




Figure 10 Khimti Khola at Khimti Besi, close to the confluence with Tama Koshi, April 2003. Photo:

Halvard Kaasa.

2.4 Hydrology

2.4.1 Water temperature

Water temperatures are measured at several places along the Khimti River. Measurements are made with small temperature loggers, HOBO water temp pro from Onset. These devices have an accuracy of ±0.2°C and log the temperature in 1 hour intervals. The instrument is shown in Figure 11.

Figure 11 Water temperature

logger

Water temperatures are logged at three places in the river. Locations are shown on the map in Figure 12.

o In the intake basin at Palati o at Khimti Banchare o at Khimti Besi



The temperature sensors have different lengths of observations with the longest running temperature time series from the station at Palati. This station started observations in March 2004 and has continuos recordings until it was emptied in November 2005. The logger at Besi has recordings from the period December 2004 until April 2005, when it was last emptied. The station at Banchare has so fare no readings reorded due to the theft of the equipment.

Figure 12 Location of measurement stations

The recordings from both Banchare and Besi are short due to theft and/or disapperance of loggers during the flood season. Both loggers have been replaced and are working properly at this time. Monthly mean water temperatures are shown in Table 1. Daily mean water temperatures are shown in Figure 13.

Table 1 Monthly mean water temperature in 2004 and 2005

2004 Month Palati Bakre Besi

January - - - February - - -

March - - - April 16.76 - - May 18.23 - -

June 17.99 - - July 17.42 - -

August 17.95 - - September 17.53 - -

October 15.23 - - November 12.48 - - December 10.97 18.61 -

2005 Month Palati Bakre Besi

January 9.81 13.48 - February 11.23 15.07 -

March 14.69 18.34 - April 15.85 19.53 - May 18.12 - -

June 19.47 - - July 18.14 - -

August 18.28 - - September 18.30 - -

October 16.21 - - November 13.45 - - December - - -



Figure 13 Water temperature registrations in Khimti River.

The temperature from all stations shows substantial diurnal variations as shown in Figure 14 and Figure 15. The diurnal temperature variations are somewhat greater further downstream as is expected. The lowest temperature is in the period 08:00 - 09:00 in the morning, and highest in the afternoon around 17:00.

14

14.5

15

15.5

16

16.5

17

17.5

18

18.5

19

01:00 05:00 09:00 13:00 17:00 21:00

Figure 14 Average diurnal variation - Palati

14

14.5

15

15.5

16

16.5

17

17.5

18

18.5

19

01:00 05:00 09:00 13:00 17:00 21:00

Figure 15 Average diurnal variation - Besi

2.4.2 Water Level Measurements

Water levels and the corresponding discharges are measured at several places along the Khimti River. Measurements of water level are done with pressure sensors with loggers, WL-15 from Global Water Instrumentation Inc. These devices have an accuracy of ±0.1% and log the water level in 1 hour intervals. The instrument is shown in Figure 11.



Water levels are logged at four locations in the river system. Locations are shown on the map in Figure 12.

o Downstream from the intake basin at Palati o Upstream in Haluwa khola o Upstream of the confluence of Khimti river and

Haluwa river o at Khimti Besi

Figure 16 Water pressure sensor with logger. The water level recorders have different length of observations with the longest running water level time series from the station at Khimti Besi. This station started observations in April 2005 and has continuous records until it was emptied in November 2005. No special events were detected in the time series. The time series is shown in Figure 18. The logger at the Haluwa/Khimti confluence has records from the period April 2005 until mid August 2005, when the logger battery went dead. During the time the logger was operating two separate changes in the

Figure 17 Location of measurement stations

river profile could be detected as seen in Figure 19. One event in august 2005 when there was a reported landslide into the river, but also one in mid may, cause unknown. Such changes in river profiles make the existing rating curve more or less useless. Two of three discharge measurements are however made after the last profile change and can be of some use later. For the moment a corresponding rating curve for this location is not constructed because at least three discharge measurements are considered necessary to generate a rating curve of any use.



0

0.5

1

1.5

2

2.5

3

01.04.05 01.05.05 01.06.05 01.07.05 01.08.05 01.09.05 01.10.05 01.11.05 01.12.05

Khimti Besi (40251) Control measurements

Figure 18 Hourly water level recordings from Khimti Besi.

0

0.5

1

1.5

2

2.5

3

3.5

4

01.04.05 01.05.05 01.06.05 01.07.05 01.08.05 01.09.05 01.10.05 01.11.05 01.12.05

Haluwa/Khimti confluence (40248) Control measurements

Profile change

Profile change

Figure 19 Hourly water level recordings from upstream the confluence of Khimti and haluwa rivers.

Profile changes indicated.

The station at Palati has only a few sporadic recordings due to the theft of the water level recorder in early June. A new recorder was installed in November 2005. The station upstream in Haluwa Khola has recordings from April until July 2005. After this the water level recorder stopped functioning due to bad batteries. The time series is shown in Figure 20.



0

0.2

0.4

0.6

0.8

1

1.2

01.04.05 01.05.05 01.06.05 01.07.05 01.08.05 01.09.05 01.10.05 01.11.05 01.12.05

Haluwa Khola (40250) Control measurements

Figure 20 Hourly water level recordings from upstream the Haluwa khola.

During the time of operation the corresponding gauges at each water level recording locations, were visited every other week in case of logger failures. These measurements are shown in the above figures as control measurements.

2.4.3 Discharge Measurements

Discharge measurements were made on three separate occasions during 2005, at all locations with water level recordings. Measurements were made in early July, late September and in late November. Engineers from Butwal Power Company carried out all measurements. Measurements were carried out using the salt dilution method using a conductivity meter. Haluwa/Khimti Confluence As mentioned earlier two of three discharge measurements, at the Haluwa/Khimti confluence, are made after the last profile change and can be of some use later. For the moment a corresponding rating curve for this location is not constructed because at least 3 discharge measurements are considered necessary to generate a rating curve of some use.



Downstream of intake at Palati

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 10 20 30 40

Rating Curve - Palati Discharge measurements - Palati

Figure 21 Temporary rating curve - Palati

Four discharge measurements were made at this site. Because there has been no functioning logger at this site, the rating curve is calibrated only with the use of stage readings on the gauge. No measurements were made during high discharges, which makes the curve uncertain. One measurement also seems erroneous.

Upstream in Haluwa Khola Measurements made upstream in Haluwa Khola are all made after the logger ceased to function. Since the measurements regarding the ratio between water level logger height and the corresponding water level height on the gauge are still missing, the rating curve can only be constructed on the basis of gauge height. Since the gauge readings compared to the corresponding discharge measurements seem to have some errors, the rating curve is not established. Khimti Besi

0

0.5

1

1.5

2

2.5

0 50 100 150 200 250

Rating Curve - Khimti Besi Discharge measurements - Khimti Besi

Figure 22 Rating curve – Khimti besi

This station has functioned without serious problems during the observation period. Three discharge measurements were made and these have been used together with the corresponding logger water level values for the establishment of a functioning rating curve. The rating curve is shown in Figure 22 and the calculated discharge time series is shown in Figure 23.



0

50

100

150

200

250

01.04.05 01.05.05 01.06.05 01.07.05 01.08.05 01.09.05 01.10.05 01.11.05 01.12.05

m³/s

Discharge - Khimti Besi

Figure 23 Discharge at Khimti besi – 2005.

All in all there has been difficult to get proper results from the water level loggers this season. Of the four loggers, two has been drained of battery power and one was stolen. Only the station at Khimti besi has been operating the whole season. The water level logger at Palati is now replaced, batteries changed on all loggers and some modification has been made in the design to prevent water leakage and consequent battery power drainage in the loggers. Hopefully this will prevent dataloss in the coming period. As a recommondation, there is a need of more discharge measurenments in 2006. These also have to be made on high discharges to calibrate the rating curves.

2.4.4 River flow Conditions

To give a brief background of the river flow conditions we present the assumed average monthly water flow (Kaasa & Bjørtuft, 2002) and the average monthly tunnel discharge in the Khimti Power station during 2000 and 2001 (source: HPL) in Table 1 and Table 2. Figure 24 gives an idea of the portion of the total flow passing through the tunnel. The figure is based on the assumptions of Table 1 and the measured data of Table 2.

Table 1 Assumed average monthly water flows (m³/s) in Khimti Khola at Palati (from Kaasa & Bjørtuft 2002, source: HPL).

Aug Sep Oct Nov Dec Jan Feb March April May June July 72.0 40.1 14.1 2.0 0.5 0.5 0.5 0.5 0.5 0.5 24.3 70.3

Table 2 Average monthly tunnel discharge (m³/s) in Khimti Khola Power Station 2000-2001

(source: HPL).

July Aug Sep Oct Nov Dec Jan Feb March April May June July 11.1 11.4 11.1 11.5 10.8 5.3 6.3 5.2 4.5 4.8 7.8 6.6 11.8



0

20

40

60

80

100

Jan

FebMarc

hApri

lMay

June Ju

lyAug Sep Oct Nov DecPe

r cen

t of t

otal

dis

char

ge th

roug

h th

e tu

nnel

Figure 24 Percentage of total discharge through the hydropower tunnel, based on measured flow

in the tunnel and assumed flow in the river. Based on data from the tables 1 and 2.

2.5 River Ecology Nepal has an area of 147 181 km2. Approximately 5% of the total area of the country is occupied by various freshwater habitats where several fish species are reported to thrive. In general, the aquatic habitats and fish species can be viewed as sources for fisheries and aquaculture development in the country. This also implies that aquatic resources located at different altitudes and climatic zones can offer potential for different fisheries and aquaculture activities in Nepal (Gurung 2002). The inland water resources of Nepal totalling 745 000 ha consist of river systems, lakes, reservoirs, village ponds, wetlands and irrigated rice fields. Nepal has more than 6000 rivers and streams with three main river systems (Sharma and Shrestha 2001). The lotic water mass of the Himalayan region comprises many torrential rivers and streams, which provide a wide variety of ecological niches for important fresh water fishes (Shrestha, T.K). Nepal has several fish species. Gurung (2002) refers to 186 fish species. Shrestha (1994) describes only 129 to avoid any repetition. Nepalese fish share many genera with those of South-East Asia, and consist mainly of carps, catfish, sheat-fish, feather-backs, eels and hill-stream fish. The climatic conditions vary from hot monsoon to alpine type. The size and number of species decline according to altitude. Only a few species of small size are found in high altitude water bodies. The hill stream fish are also unique, as they have developed many adaptive characteristics to sustain themselves in fast-flowing waters (Shrestha, J. 1994). The Khimti river system with its main catchment in medium and high altitudes has a steep gradient with a low number of fish species in the upper parts of the river. At about 600 m above sea level Khimti Khola confluences with the Tama Koshi, which is reported to have between 30 and 40 registered fish species. When entering the low altitude areas, this river reaches the Ganges system, which is rich in species. Long migratory species from low altitudes are thus able to reach Tama Koshi and Khimti Khola.



Registrations in the lower parts of Khimti Khola show fifteen different fish species so far as listed in Table 3. At the intake site at Palati 1250 m above sea level the registrations show 6 species. Midrange migratory species (MD) may have developed a migratory behaviour within a range of some kilometres and thereby have a home area both in Khimti Khola and Tama Koshi. Resident species (RE) have their home area in Khimti Khola. A clear gradient was observed: fortheen different fish species have been caught at Besi - Gobantar, nine at Palati and five 4.5 km further upstream, at Rasnalu. Among the fortheen species previously registered in the lower parts of the river five species are listed as midrange migratory species. Of the nine fish species being registered at Palati, two are midrange migratory fish species. Three fish species are generally greater in number than the others: asala, or spotted mountain trout (Schizothorax plagiostomus) dominates at all stations, and consists of close to 80% of the total catches. Katle, or copper mahseer, (Acrossocheilus hexagonolepis) and titae, or stone carp (Psilorhynchus pseudecheneis) consist each roughly of about one tenth of the total catches. In the further chapters of this report the species will be mentioned by their local name. Table 3 Fish species registered in Khimti Khola from 1990 to 2004.

RE-resident (Khimti Khola), MD-midrange migrant (Tama Koshi – Khimti Kohla).

English Name Latin Name Local Name MigratoryStatus

Spotted Mountain Trout Schizothorax plagiostomus Asala MD/RE Point-nosed Snow Trout Schizothorax progastus Chuche Asala MD Blunt-nosed Snow Trout Schizothorax richardsonii Buche Asala MD Copper Mahseer Acrossocheilus hexagonolepis Katle MD River Barb Tor (Puntius) chelynoides Halundae MD Lohari Crossocheilus latius latius Petphora, Lohari RE Sucker Head Garra gotyla gotyla Buduna, Nakato RE River Carp Labeo dero Gurde MD/RE Stone Carp Psilorhynchus pseudecheneis Titae RE Creek Loach Nemacheilus beavani Gadero, Masani RE Stone Loach Nemacheilus rupicola Sime RE Three-lined catfish Glyptothorax trilineatus Tel Cabre RE Catfish Glyptothorax cavia Bhitte RE Sucker Throat Catfish Pseudecheneis sulcatus Labre, Kabre RE Gardi A few of the fish species observed at Gobantar and Khimti Besi were found only in low numbers. A reduced number of fish species is a common phenomenon in the upper parts of steep rivers. (T.K. Shrestha, pers. comm. and report: Fisheries Resources of Khimti River, 1994). BPC, the local consultant, has reported that the fishing activity has increased during the low flow season after the Khimti I hydropower plant started its operation. Diverting the river at points where the physical conditions make it possible is an old way of catching fish in Nepal. In Khimti Khola it was laborious to do it before the hydropower regulation. Now this method is combined with the use of poison. When the flow was reduced due to the intake of water at Palati many sites were



exposed as suitable diverting areas. Use of poison to catch fish is an illegal activity according to the rules and regulations of Nepal. River diversion and use of poison have, however, been registered at 48 different places downstream of Palati (Rakesh 2006). This is regarded as a dramatic threat to the future of the fish populations downstream of Palati (Rakesh 2003). In Nepal there are many herbal plants from the local forest that could be used for poisoning fish, such as: Khirro (Sapium insigne), Ratopire (Polygoneum viscosum), Setopire (Polygoneum flaccidum), Bhogate (Maesa macrophylla), Okhar (Juglans regia), Sihudi (Euphorbia royelana), Narayanpati (Buddleia paniculata), Bhimsenpati (Buddleia asiatica), Kattuke (Agave americana-century plant), and Mahua (Engelhardtia spicata) (Rakesh 2003).

Figure 25 Herbal plants are used for poisoning fish in Khimti Khola.



3 METHODOLOGY

3.1 Water quality The following parameters were analyzed in January 2004 and July 2005 according to standard procedures: pH Conductivity, (µmhos/cm) Turbidity, (NTU) Total alkalinity as CaCO3, (mg/l) Nitrate - N, (mg/l) Dissolved Phosphate, (mg/l) Dissolved Oxygen, (mg/l) Total Coliform Count, (MPN Index /100ml) E. Coli, (MPN Index /100ml) In addition a registration of any presence of Giardia cysts, worms or larvae and ova was carried out. All analyses and observations were made with three samples from each station. The BPC sampling procedures are as follows: The samples for all parameters were taken from the mid section of the river to attain homogeneity. Depending on the parameters to be analyzed samples were collected in PVC bottles and preserved with different types of additives. Samples for physical and chemical tests: Samples for physical and chemical tests were collected in a 1000 ml PVC bottle. The sample bottle was washed at least three times with the sample water prior to sample collection. After collection the samples were stored in an ice box at 4°C. Samples for microbiological tests Samples for microbiological test were collected in a 75 ml sterilized bottle. Prior to taking samples, hands and external parts of the bottle were sterilized with ethanol. These samples were also stored at 4°C after collection. Samples for biological tests: Samples for biological tests were also collected in 1000 ml PVC bottles. After collection the samples were stored at 4°C. Samples for Dissolved Oxygen: The D. O. samples were collected in 300 ml glass bottles. The samples were collected very gently in order to prevent the dissolution of external oxygen. Immediately after collection, the D.O. is trapped with the addition of manganous sulphate (1 ml) and alkali azide (1 ml). These samples were also stored in an ice box at 4°C.



3.2 Electrofishing Electrofishing is carried out in order to register mostly the juvenile fish densities in the low flow season. To be able to compare the results with data from previous registrations, the method used was successive removal, which is the same method as used during the IFC - Supplementary Environmental Assessment study, 1994. The sampling areas was marked along the river bottom and measured. The restricted areas were fished three times, with an interval of half an hour. Zippin (1956, 1958) is generally referred to when making use of successive removals, as he reviewed this method and provided graphs by which the population size and the catchability could be estimated. Actually the formula given by Junge and Libosvarsky (1965) was used, as they found an explicit solution for the case of three removals, as reviewed by Bohlin et al. (1989). More details concerning the calculations are given as an annex in Kaasa & Bjørtuft (2002). The length and fish species are recorded for each fishing round. Densities are given as number of fish per 100 m², and thus calculated in the same way as in the ICF (1994) report. In general the youngest cohorts are represented by lengths less than 5 cm. As the smaller fish generally is more difficult to catch, and the results therefore are more unreliable, the densities are calculated separately for fish up to 5 cm and longer. In 2005 the electrofishing was carried out in April, by means of equipment produced by Geomega, Norway, with a maximum voltage of 1600 V and a frequency of 80 Hz.

3.3 Cast nets Cast nets are the most common fishing techniques used in mountain fisheries in both India and Nepal (Payne et al. 2003). This is a fishing method deeply rooted in the local culture, and the local fishermen have shown a good ability to capture different fish species with cast nets (Figure 26). The net used in this project has a standard size and local fishermen with long experience are employed for net casting. Use of cast nets is therefore considered a convenient and sustainable method to monitor the long-term changes in the fish population. The method provides a basis for calculation of catch per unit effort (CPUE). In this report the results are presented as fish per 100 casts. The cast nets are circular, with diameter of 270 cm. The mesh size gradually decreases from 40 mm in the centre to 17 mm at the circumference. Table 4 shows how many meshes there are of each size. Between 105 and 110 metal weights, each of 40g, are attached to the circumference of the cast net. For all casts the cast number, date, time, weather condition, and water colour have been recorded. When fish are caught, species, length, weight, and sexual maturity are recorded. At each station the fishing activity was performed in two periods every day 5.00 – 8.00 AM and 5.00 – 8.00 PM. Due to the security situation the latter was changed in September 2003, and the cast net fishing activity has since then been carried out in the hours 3.30 – 6.30 PM. The fishermen carried out 90-100 casts on each station and over a distance up to 1.5 km. Fishing with cast nets was carried out during the period from pre-monsoon till post-monsoon with sampling every second week at three locations, and with a high effort at each site. During the rest of the year, sampling was undertaken every month.



Table 4 Mesh sizes of a circular cast net with diameter of 270 cm

Number of meshes from centre of cast net

Mesh size in mm

8 40 3 35 8 32 2 30 2 27 2 25 2 24 7 23 9 21 12 18 25 17

Figure 26 Cast nets are traditionally used in Nepal, here at Palati.

Photo: Halvard Kaasa



4 RESULTS

4.1 Water quality The results from the water quality analysis in January July 2005 are shown in Table 5 and 6. Table 5 Results from the water quality analysis in January 2005 from four stations at Khimti

Khola: A1 - upstream of Palati, A2 - 1 km downstream of Palati, A3 - upstream of the confluence with Haluwa Khola, and A4 - Khimti Besi.

Parameters A1 A2 A3 A4

pH 7.5 7.5 7.5 7.6 7.6 7.6 7.6 7.6 7.6 7.5 7.5 7.5

Conductivity, (µmhos/cm) 85 85 86 87 86 87 79 78 79 65 66 65

Turbidity, (NTU) <1 <1 <1 <1 <1 <1 7 6 6 3 3 3

Total alkalinity as CaCO3, (mg/l) 40 40 40 40 40 40 40 35 40 25 25 25

Nitrate - N, (mg/l) 0.18 0.17 0.18 0.18 0.17 0.17 0.13 0.13 0.13 0.12 0.13 0.13

Dissolved Phosphate, (mg/l) 0.02 0.02 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.04 0.05 0.06

Dissolved Oxygen, (mg/l) 10.04 10.04 9.82 9.63 9.34 9.66 9.9 9.63 9.76 9.92 9.81 9.72

Total Coliform Count, (MPN Index /100ml) 460 460 48 460 240 460 460 460 240 93 240 240

E. Coli, (MPN Index /100ml) 150 48 48 93 150 150 75 460 48 48 93 48

Giardia Cyst 0 0 0 0 0 0 0 0 0 0 0 0

Worms / Larvae 0 0 0 0 0 0 0 0 0 0 0 0

Ova 0 0 0 0 0 0 0 0 0 0 0 0

Other aquatic ogranismens 1

motile type

0 0 1

motiletype

2 types 0 0 0 0 2

types

1 motile type

1 motile type

For the chemical parameters the results of the three series only differed slightly. The pH was 7.5 to 7.6 in all samples. The conductivity showed decreasing values from the upper to the lower station, with values from 87 to 65 µmhos/cm. The values of turbidity decreased downwards, with 6 to 7 NTU upstream of the confluence with Haluwa Khola. Total alkalinity and nitrate gradually decreased in values from Palati to Khimti Besi. For dissolved phosphate the values increased downwards, whereas dissolved oxygen had similar numbers at the upper and lower station. For the bacteria results there is a different pattern. Both the total coliform counts and those of the bacteria Escherichia Coli showed more variation in the samples within one station than between different stations. The variation within the station may origin from the dissolvement of particles. The nunbers of Escherichia Coli indicates a good (< 100) to less good (100 – 1000) water quality with reguards of bathing according to EU standards. No Giardia cyst, worms or larvae and ova were found.



Table 6 Results from the water quality analysis in July 2005 from four stations at Khimti Khola: A1 - upstream of Palati, A2 - 1 km downstream of Palati, A3 - upstream of the confluence with Haluwa Khola, and A4 - Khimti Besi.

Parameters A1 A2 A3 A4

pH 8.2 7.7 7.1 7.2 7.2 7.1 7.0 7.1 7.9 7.2 8.1 7.1

Conductivity, (µmhos/cm) 52 44 31 32 30 30 32 30 52 33 53 33

Turbidity, (NTU) 8 9 7 8 7 9 7 7 8 7 9 7

Total alkalinity as CaCO3, (mg/l) 20 27.5 20 20 15 20 17.5 20 30 17.5 30 20

Nitrate - N, (mg/l) 0.16 0.13 0.14 0.12 0.16 0.21 0.28 0.12 0.14 0.13 0.13 <0.10

Dissolved Phosphate, (mg/l) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Dissolved Oxygen, (mg/l) 7.0 7.74 7.70 7.78 7.81 7.4 8.20 8.59 7.5 7.60 7.76 7.50

Total Coliform Count, (MPN Index /100ml)

>1100

>1100

>1100

>1100

>1100

>1100

460

1100

460

460

>1100

93

E. Coli, (MPN Index /100ml) >1100 460 1100 >1100 >1100 460 93 460 93 48 1100 48

Giardia Cyst 0 0 0 0 0 0 0 0 0 0 0 0

Worms / Larvae 0 0 0 0 0 0 0 0 0 0 0 0

Ova 0 0 0 0 0 0 0 0 0 0 0 0

For the chemical parameters the results of the three series only differ slightly. The pH was 7.1 to 8.2 in all samples. The conductivity shows decreasing values from upstream of Palati to downstream, with values from 52 to 30 µmhos/cm. The turbidity values were almost the same at all stations. Total alkalinity and nitrate was also in general the same at all stations, and varies more inside one station than between stations. For dissolved phosphate the values are not detectable. D.O increases from upstream Palati to upstream of the confluence with Haluwa Khola, and decreases down to Khimte Besi. For the bacteria results the total coliform count was higher upstream than downstream in Khimte Khola. The results of the bacteria Escherichia Coli show variation in the samples within one station, but also show a tendency of higher numbers upstream than downstream. The nunbers of Escherichia Coli (100 – 1000) indicates less good water quality with reguards of bathing according to EU standards. No Giardia cyst, worms or larvae was found. The results from winter (January) and summer (July) show a great variation in both biotic and abiotic factors.

4.2 Electrofishing During the electrofishing of March 2005 twelve species were registered (Table 7). The results confirm the general gradient of a more diverse river ecology further downstream compared to the upper stations. Nine fish species are present at Khimti Besi and Gobantar, but only seven of them are present at both these stations. Fish densities, based on the successive removal method, serve as a good basis for comparative studies over years and between stations. The baseline data from electrofishing is documented in the IFC report from 1994. To give a better possibility to compare the 2005 data with earlier data, diagrams with available data from electrofishing in 1994, 2001, 2003 and 2004 are provided. The monitoring activity is performed at two stations above the intake site. Rasnalu, about 4.5 km upstream of it, and the Palati station, about 300 m upstream of the intake site. At these stations it was only possible to carry out electrofishing in restricted areas along the shore.



The low flow situation downstream of the weir at Palati made electrofishing across the total riverbed possible. The wet area has been reduced significantly after regulation during low flow situation. At Banchare the situation was similar, but with a higher discharge. The conditions were still satisfactory for performing electrofishing across the riverbed. At Gobantar and Khimti Besi the increased flow was too high to carry out electrofishing in the entire cross section of the river. For 2005 the most common species registered are still Asala, Titae,and Katle. The length frequencies of these species from all stations appear in Figure 27, Figure 28 and Figure 29.



Table 7 Fish species registered in Khimti Khola by means of electrofishing April 2005, being the basis for calculating length frequencies and

fish densities.

Schizo-Thorax Plagio-Stomus

Schizo -Thorax Proga-Stus

Schizo -Thorax Richard-Sonii

Acrosso -Cheilus Hexa-Gonolepis

Crosso-Cheilus Latius Latius

Garra Gotyla Gotyla

Psilor-Hynchus Psedu-Cheneis

Nema-Cheilus Beavani

Nema-Cheilus Rupicola

Pseudecheneis Sulcatus

Glypto-Thorax Trilineatus

Psilorhynchus Sulcatus

Total

Asala Chuche Asala

Buche Asala Katle Lohari Nakato Titae Masani Sime Kabre Tel Cabre Labre Gardi

Rasnalu 170 127 1 15 4

Palati upstream 184 4 27 3 3 5

Palati downstream 146 2 25 4 6 5

Banchare 197 37 15 5 1 5

Gobantar 174 8 82 5 12 30 9 15 1 9

Khimti Besi 145 20 19 1 66 20 41 1 1 9

All stations 1016 28 144 5 13 290 29 61 9 25 1 1 12



0

20

40

60

80

100

120

10 30 50 70 90 110 130 150 170 190 210 230 250 270 290Length in mm

Figure 27 Asala, length frequency of 1016 Schizothorax Plagiostomus (Spotted Mountain Trout),

caught by means of electrofishing, from all stations in Khimti Khola, March 2005.

0

20

40

60

80

100

120

10 30 50 70 90 110 130 150 170 190 210 230 250Length in mm

Figure 28 Titae, length frequency of 290 Psilorhynchus Pseudecheneis (Stone Carp,) caught by

means of electrofishing, from all stations in Khimti Khola, March 2005.

0

20

40

60

80

100

120

10 30 50 70 90 110 130 150 170 190 210 230 250Length in mm

Figure 29 Katle, length frequency of 144 Acrossocheilus Hexagonolepis (Copper Mahseer),

caught by means of electrofishing, from all stations in Khimti Khola, March 2005.



The total sample of asala caught in 2005 was 1016 fish. In Figure 30 this sample is split between the local sampling stations, and data from previous studies are also included to enable an examination of possible changes in the length frequencies along the river and along the time axis. The water flow at the two upper stations, Rasnalu and Palati upstream, has not been affected by the hydropower regulation. As no age determination has been carried out, it is not possible to point out the different cohorts exactly. However, Figure 30 may show two different cohorts for 2005 in Rasnalu and Palati upstream, and three cohorts for 2005 in Gobantar and for 2003 and 2004 in Banchare. Figure 30 also shows that there are registered larger fish in the samples from the lower stations than at Rasnalu. Downstream from Rasnau to Khimti Besi there is a tendensy to a increasing length of asala bigger than 90 mm.

Figure 30 Asala, length frequencies (given as per cent on the y-axis) of Schizothorax plagiostomus

(spotted mountain trout) caught by means of electrofishing in Khimti Khola. Length groups are given in mm. (Lengths >250 mm are accumulated on the right hand side of the x-axis)

1994

01020304050

10 50 90 130 170 210 250

Ras

nau

2001

01020304050

10 50 90 130 170 210 250

2003

01020304050

10 50 90 130 170 210 250

2004

01020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 250

Pal

ati u

pstre

am

01020304050

10 50 90 130 170 210 2500

1020304050

10 50 90 130 170 210 2500

1020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 250

Pal

ati d

owns

tream

01020304050

10 50 90 130 170 210 2500

1020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 250

Ban

char

e

01020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 2500

1020304050

10 50 90 130 170 210 2500

1020304050

10 50 90 130 170 210 250

Gob

anta

r

01020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 2500

1020304050

10 50 90 130 170 210 250

Khi

mti

Bes

i

2005

01020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 250

01020304050

10 50 90 130 170 210 250



Figure 31 Lower: Spotted Mountain Trout (Schizothorax Plagiostomus), locally called Asala,

Upper: Copper Mahseer, (Acrossocheilus hexagonolepis), locally called Katle. Photo: Halvard Kaasa.

Figure 32 Stone Carp (Psilorhynchus Pseudecheneis), locally called Titae

Photo: Halvard Kaasa The dominating species at all stations is asala (Schizothorax plagiostomus) (Table 8 – Table 12). In 2005 asala shows the highest densities at the upper stations, Rasnalu and Palati. Even the lower limits of the confidence values show high densities at these stations. To calculate densities with an acceptable degree of probability, it is necessary to have samples of each species that satisfy the formula of the successive removal method. Some of the species were caught in too low numbers to provide a valid basis for such calculation. Although twelve



species were registered by electrofishing, only five of them satisfy the formula requirements: Asala, Katle, Titae, Masani and Sime. The estimated densities (with confidence limits) from electrofishing in 2005 of Asala are shown for all stations and fish sizes in Table 8. A higher density is found at Rasnalu and Palati upstream. Contrary to the results from 2003-2004, the estimated density for all Asala downstream of the weir is more than half the density of upstream. In general the total density above Palati is higher than at the lower stations. The estimated density of Asala less than 50 mm varied from 0 at Rasnalu and Palati downstream the weir to 96,6 indivuduales / 100 m2. The big differences in estimated dencities could be an expression of biotope differences and cacthability due to different water velocities. It might also be an expression of low catchability of small fish. If we look at estimated densities for Asala bigger than 90 mm, this was highetst at Rasnalu (table 8). The differnences between the different stations was less for the bigger than for the smaller fish. Table 8 Estimated densities of Asala in Khimti Khola March 2005

(Empty spaces indicate no basis for calculation.) All fish sizes

Stationarea (m²) number

caughtest. density (n/100m²)

lower limit

upper limit catchability

Rasnalu 125 170 167,6 141,4 193,7 0,43Palati upstream of intake 147 184 165,1 132,7 197,5 0,38Palati downstream of weir 194 146 80,6 75,2 86,0 0,60Banchare 310 197 71,6 65,2 78,0 0,52Gobantar 196 174 111,3 92,8 129,8 0,41Khimti Besi 275 145 70,4 54,1 86,7 0,37

Fish 0 - 50 mm



lower limit


Rasnalu 125 13 - - - -Palati upstream of intake 147 81 96,6 34,4 158,9 0,25Palati downstream of weir 194 13 - - - -Banchare 310 35 6,1 3,0 9,2 0,45Gobantar 196 37 41,2 -19,2 101,6 0,18Khimti Besi 275 15 5,8 4,6 7,1 0,59

Fish > 50 mm



lower limit



95% conf. int.

95% conf. int.

95% conf. int.



As for Asala the estimated density of titae was highest at Rasnalu (table 9), and more than five times denser than at the five lower stations. Fish from 0 to 50 mm dominates the population caught at Rasnalu. Titae was present at all stations. The densest estimated population over 50 mm was at Palati upstreame of weir and Khimti Besi.

Table 9 Estimated densities of the Stone Carp, Psilorhynchus pseudecheneis, (Titae) in Khimti Khola March 2005

(empty spaces indicate no basis for calculation).

All fish sizes



lower limit



Fish 0 - 50 mm



lower limit


Rasnalu 125 118 129,9 93,1 166,7 0,4Palati upstream of intake 147 5 3,4 3,2 3,7 0,8Palati downstream of weir 194 6 3,1 2,9 3,3 0,8Banchare 310 2 - - - 0,0Gobantar 196 1 0,5 0,5 0,5 1,0Khimti Besi 275 1 0,4 0,4 0,4 1,0

Fish > 50 mm



lower limit



95% conf. int.

95% conf. int.

95% conf. int.



The estimated densities of Katle were highest at the lower stations as Banchare, Gobantar and Khimti Besi (table 10). The density at Gobantar was more than three times as high as the next densest place. Katle was present in the catches at all stations eccept for Rasnalu. The share of fish from 0 to 50 mm at all stations was low.

Table 10 Estimated densities of Katle in Khimti Khola, March 2005

(Empty spaces indicate no basis for calculation).

All fish sizes



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 4 - - - -Palati downstream of weir 194 2 1,0 1,0 1,0 1,0Banchare 310 37 12,1 11,5 12,8 0,7Gobantar 196 82 45,9 40,7 51,1 0,6Khimti Besi 275 19 11,2 -1,2 23,5 0,3

Fish 0 - 50 mm



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 0 - - - -Palati downstream of weir 194 1 - - - -Banchare 310 2 0,6 0,6 0,6 1,0Gobantar 196 3 1,9 -0,6 4,5 0,4Khimti Besi 275 0 - - - -

Fish > 50 mm



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 3 2,6 -0,8 5,9 0,4Palati downstream of weir 194 0 - - - -Banchare 310 35 11,5 10,8 12,2 0,7Gobantar 196 79 44,1 39,1 49,0 0,6Khimti Besi 275 19 11,2 -1,2 23,5 0,3

95% conf. int.

95% conf. int.

95% conf. int.



Masani was only found at two lower stations (table 11), and the densities were low. No fish were found from 0 to 50 mm in size.

Table 11 Estimated densities of Masani in Khimti Khola March 2005. (Empty spaces indicate no basis for calculation).

All fish sizes



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 0 - - - -Palati downstream of weir 194 0 - - - -Banchare 310 0 - - - -Gobantar 196 8 6,0 -1,8 13,8 0,3Khimti Besi 275 20 7,6 6,6 8,6 0,7

Fish 0 - 50 mm



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 0 - - - -Palati downstream of weir 194 0 - - - -Banchare 310 0 - - - -Gobantar 196 0 - - - -Khimti Besi 275 0 - - - -

Fish > 50 mm



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 0 - - - -Palati downstream of weir 194 0 - - - -Banchare 310 0 - - - -Gobantar 196 8 6,0 -1,8 13,8 0,3Khimti Besi 275 20 7,6 6,6 8,6 0,7

95% conf. int.

95% conf. int.

95% conf. int.

The density of Sime was highest at the lowest station (Table 12), and the species was also present at Bachare and Gobantar.



Table 12 Estimated densities of Stone Loach, Nemacheilus Rupicola, (locally called Sime) in Khimti Khola, March 2005. (Empty spaces indicate no basis for calculation).

All fish sizes



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 0 - - - -Palati downstream of weir 194 0 - - - -Banchare 310 5 1,7 1,2 2,1 0,7Gobantar 196 15 10,8 1,5 20,1 0,3Khimti Besi 275 41 17,2 13,3 21,2 0,5

Fish 0 - 50 mm



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 0 - - - -Palati downstream of weir 194 0 - - - -Banchare 310 2 - - - 0,0Gobantar 196 5 4,3 -5,6 14,1 0,3Khimti Besi 275 6 4,1 -7,2 15,4 0,2

Fish > 50 mm



lower limit


Rasnalu 125 0 - - - -Palati upstream of intake 147 0 - - - -Palati downstream of weir 194 0 - - - -Banchare 310 3 1,0 1,0 1,0 1,0Gobantar 196 10 6,8 0,9 12,6 0,4Khimti Besi 275 35 14,2 11,4 17,1 0,5

95% conf. int.

95% conf. int.

95% conf. int.

Figure 33 Stone Loach (Nemacheilus Rupicola), locally called Sime.

Photo: Halvard Kaasa



4.3 Long Term Development It is often a good approach to follow changes in fish populations over many years to evaluate the development. New data from 2005 of asala, titae and katle are presented in Figure 34 – Figure 38 together with available data from previous studies. The sampling in 1994 provided for data from Rasnalu, Palati upstream and Gobantar. We have in addition data from Palati downstream since 2001 and from Banchare and Khimti Besi since 2003.

4.3.1 Rasnalu

The estimated densities of asala show an increasing tendency after 2001, and the density is more than four times higher in 2005 than in 2001 (Figure 34a and b). The population seams dominated by fish more than 50 mm (Table 8 and Figure 34b). The estimated densities for Titae after 2004 in Rasnalu show an increasing tendency (Figure 34c). The population seams to exist mainly by young fish from 0 to 50 mm (Table 7 and Figure 34c).

40 80

120 160 200 240

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

0-50 mm titae

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

density (n/100 sqm)

d)

Figure 34 Asala and Titae: Estimated densities of a) all Asala b) Asala more than 50 mm c) all

Titae and d) Titae 0-50 mm at Rasnalu, shown with 95% confidence limits.

4.3.2 Palati Upstream

Asala estimated densities upstream of Palati is high as at Rasnalu, and has increased since 2004 (Figure 35a). Both fish less and more than 50 mm have increased noticeably since 1994 and 2001 (Table 8 and Figure 35b) and c). Titae populations at the station seem stable low and mainly consist of individuals more than 50 mm (Table 9 and Figure 35d).

all asala

0 40 80

120 160 200 240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

density (n/100 sqm)

a) >50 mm asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

density (n/100 sqm)

b)

1993 1994

density (n/100 sqm)

all titae

0

c)



all asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

a)0-50 mm asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

b)

>50 mm asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

c)

all titae

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

d)

Figure 35 Asala and Titae, estimated densities of a) all Asala b) 0-50 mm Asala c) >50 mm Asala

and d) all Titae at Palati upstream, shown with 95 % confidence limits.

4.3.3 Palati downstream

The estimated density, of asala downstream the weir of Palati is half the estimated density upstream of Palati weir. For all lengths combined there is hardly any difference between the years (Figure 36a). But if split, one can observe an increasing tendency for longer fish (Figure 36b), and a low number of recruitment of fish from 0 to 50 mm (Table 8).

all asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

a)

>50 mm asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

b)

Figure 36 Asala, estimated densities of a) all Asala and b) >50 mm Asala at Palati Downstream

in 2001 to 2005, shown with 95 % confidence limits.



4.3.4 Banchare

At Banchare the estimated densities of Katle and Titae was low and apparently stable. (Figure 37a) and b). The Asala density is increasing (Figure 37c), with a high increase in fish more than 50 mm, and a weak increase in fish less than 50mm (Figure 37d and 37e).

all asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

c)

0-50 mm asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

d)

>50 mm asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

e)

all titae

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

b)

all katle

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

a)

Figure 37 Asala, Titae and Katle, estimated densities of a) all Katle, b) all Titae, c) all Asala, d)

0 to 50 mm Asala and e) >50 mm Asala at Banchare shown with 95 % confidence limits.

4.3.5 Gobantar

The estimated density of all asala at Gobantar has increased since 2003, and the density is higher than the estimated earlier peak density in 2001 (Figure 38a). Also the estimated density for fish longer than 50 mm shows the same tendency (Figure 38b). Gobantar is the station where the highest Katle densities are found (Table 10), and it shows a strong increasing tendency the last three years (Figure 38c).



all asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

a)

>50 mm asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

b)

all katle

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

c)

Figure 38 Asala and Katle, estimated densities of a) all Asala, b) >50 mm Asala and c) all Katle

at Gobantar, shown with 95% confidence limits.

4.3.6 Khimti Besi

The estimated densities of Asala, Titae and Katle, indicating a decrease for 2003 to 2004, and high increase in 2005 at Khimti Besi.(Figure 39a,b and c). Especially for Katle the estimated density is almost eight times higher than in 2004. The population of Titae seems to consist of species longer than 50 mm, and the recruitement is very low (Table 9 and Figure 39d).

all asala

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

a)

all titae

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

c)>50 mm titae

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

d)

all katle

0

40

80

120

160

200

240

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

dens

ity (n

/100

sqm

)

b)

Figure 39 Asala, Titae and Katle, estimated densities of a) all Asala, b) all Katle, c) all Titae and

d) >50 mm Titae at Khimti Besi, shown with 95 % confidence limits.



4.4 Cast nets During the registrations of 2004-2005 seven fish species were registered by cast nets, as listed in Table13, including the stations Banchare and Khimti Besi where the cast net fishing started in April 2004. Asala dominates in the catches, with Titae and Katle Alter as number two and three in abundance among the fish species (Table 13). Nakato and buduna appears at the two lower stations in low but significant numbers. Table 13 Fish species registered in Khimti Khola by means of cast nets during 2004 - 2005.

Schizo-thorax plagio-stomus

Acrosso-cheilus hexa-

gonolepis

Crosso-cheilus latius latius

Garra gotyla gotyla

Psilor-hynchus psedu-cheneis

Pseude-cheneis sulcatus

Garra annandal

ei

CPUE as

number of fish

per cast

CPUEas

number of fish

per cast

Total

asala katle lohari nakato titae kabre buduna

Totalno of fish

no of casts

2003-2004 2004-2005

Rasnalu 124 4 0 0 45 0 0 173 3465 0.039 0.050 3

Palati upstream 387 71 0 2 96 2 0 558 3415 0.128 0.163 5

Palati downstream 260 37 0 0 56 3 0 356 3449 0.107 0.103 5

Banchare 196 75 0 8 36 1 0 316 3451 0.078 0.092 5

Gobantar 147 117 5 25 24 7 0 325 3464 0.090 0.094 6

Khimti Besi 98 44 10 21 24 1 21 219 3461 0.06 0.063 7

All stations 1212 341 15 56 281 14 21 1940 20705 0.079 0.094 7

Cast nets were used in the morning (5-8 am) and in the evening (3.30-6.30 pm) throughout the fishing period. During the monsoon period sampling was done every second week, and the rest of the year every month. The numbers of casts are presented in Table13. The catch results are converted into fish per 100 casts for each month with fishing activity. Figures 40 to 49 include data from 2000 to 2005, and present thus a period of five years for the respective stations, except the two new ones. The details are, however, more accurate in the tables as only one symbol is shown in the figures when there are “overlaps”. A water flow diagram is presented together with the cast net results for the station upstream Palati weir. The figure on water flow is based on Table 1 and Table 2, presented under 2.4 Hydrology, page 12. This enables an evaluation of the water flow’s importance in connection with the recorded cast net data (Figure 42). The results are presented downwards, starting with Rasnalu.

4.4.1 Rasnalu

At Rasnalu the highest catches (as CPUE) in 2004-2005 are recorded in July for Asala and in June and July for Titae. Asala dominates generally, with far higher values than Titea, which was present in most of the samples from all months, except from December through March. In 2004-2005 Katle was only present in the catches from July, August and October (Table14). Kabre has not been recorded since 2003.



Table 14 Total cast net catches (per 100 casts) at Rasnalu 2004-2005.

The last seasons seem generally to have provided lower values than the previous years (Figure 40), and the peaks have lower amplitudes. The peaks seam to appear from September trough December.

-113579

11131517192123252729313335

July

200

0

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

1

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

2

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

3

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

4

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

2O

O5

No.

of f

ish

per 1

00 c

asts

asala

katle

titae

Figure 40 Cast net catches (per 100 casts) at Rasnalu 2000-2005,

Data from 2000-2003 are taken from Kaasa & Bjørtuft (2002, 2003).

4.4.2 Palati Upstream

Considering river flow this station is comparable with Rasnalu since both stations still have natural flows. Also Asala dominated among the fish species at this station, but with some Katle and Titae also present (Table15). The number of Asala seems more stable than the two other species, but all

Schizothorax plagiostomus

Acrossocheilus hexagonolepis

Psilorhynchus pseducheneis

Asala Katle Titae

Total

June 5.9 0.0 2.6 8.5 July 6.6 0.4 2.6 9.6 August 2.7 0.3 0.3 3.2 September 2.7 0.0 0.5 3.3 October 2.2 0.3 1.4 3.8 November 1.7 0.0 1.7 3.4 December 4.9 0.0 0.0 4.9 January 1.6 0.0 0.0 1.6 February 1.1 0.0 0.0 1.1 March 0.0 0.0 0.0 0.0 April 2.2 0.0 0.0 2.2 May 5.0 0.0 2.5 2.7



species do have variations from one month to another, and it is hard to find any pattern relating the CPUE value to the monsoon cycle (Table15 and Figure 41). The presented water flow (Figure 41) is based on the calculated medium flows in the river, which does not give the desired possibility to evaluate fish catches related to the exact flow. The zigzag character of the Asala curve makes it difficult to search for trends. The estimated peak density in May each year seams to decrease especially for Asala, however the peak values in May 2005 were higher than in 2004 (Figure 41).

0

10

20

30

40

50

60

70

80

90

July

200

0

Oct

ober

Janu

ary

April

July

200

1

Oct

ober

Janu

ary

April

July

200

2

Oct

ober

Janu

ary

April

July

200

3

Oct

ober

Janu

ary

April

July

200

4

Oct

ober

Janu

ary

April

July

200

5

Wat

er fl

ow in

m³/s

-113579

11131517192123252729313335

July

200

0Se

ptem

ber

Nov

embe

rJa

nuar

yM

arch

May

July

200

1Se

ptem

ber

Nov

embe

rJa

nuar

yM

arch

May

July

200

2Se

ptem

ber

Nov

embe

rJa

nuar

yM

arch

May

July

200

3Se

ptem

ber

Nov

embe

rJa

nuar

yM

arch

May

July

200

4Se

ptem

ber

Nov

embe

rJa

nuar

yM

arch

May

July

2O

O5

No.

of f

ish

per 1

00 c

asts

asala

katle

titae

Figure 41 Cast net catches (per 100 casts) at Palati upstream 2000-2005, data from 2000-2003 are taken from Kaasa & Bjørtuft (2002, 2003). The water flow is based on Table 1 and Table 2.



Table 15 Total cast net catches (per 100 casts) at Palati upstream, 2004-2005.

4.4.3 Palati downstream

At Palati Downstream station the same fish species dominate and are represented in the samples as at the station above the intake weir. Estimated values are throughout lower than the upstream levels, and seems to be roughly 40 percent of those. As for Palati Upstream, the estimated peak density in May each year seams to decrease, especially for the Asala species. The peak values in May 2005 were less than half of the values estimated in May 2002, but still higher than in May 2001 (Figure 42).

Table 16 Total cast net catches (per 100 casts) at Palati downstream, 2004-2005.



Garra gotyla gotyla



Asala Katle Nakato Titae Kabre

Total

June 16.6 5.9 0.0 4.0 0.0 26.5 July 18.8 3.1 0.0 4.1 0.0 26.0 August 11.7 1.4 0.0 2.2 0.3 15.6 September 14.1 4.8 0.0 3.4 0.0 22.3 October 9.5 1.1 0.0 2.2 0.0 12.8 November 4.4 0.0 0.0 0.0 0.6 5.0 December 3.3 0.0 0.0 1.7 0.0 5.0 January 1.1 0.0 0.0 0.0 0.0 1.1 February 1.1 0.0 0.0 1.1 0.0 2.2 March 4.4 0.0 0.0 1.7 0.0 6.1 April 3.3 0.0 0.6 3.9 0.0 7.7 May 19.2 1.8 0.3 4.8 0.0 26.0





Asala Katle Titae Kabre

Total

June 10.3 2.8 3.9 0.0 16.9 July 13.4 2.2 1.1 0.0 16.6 August 11.1 2.4 2.0 0.2 15.8 September 10.0 0.8 3.3 0.3 14.4 October 5.8 0.3 0.8 0.0 6.8 November 0.5 0.0 0.5 0.0 1.1 December 1.6 0.0 0.5 0.0 2.2 January 1.7 0.0 0.0 0.0 1.7 February 2.2 0.0 0.0 0.0 2.2 March 6.0 0.5 1.1 0.0 7.7 April 1.6 0.0 2.7 0.0 4.4 May 8.2 0.3 1.1 0.3 9.9



-113579

11131517192123252729313335

July

200

0

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

1

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

2

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

3

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

4

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

2O

O5

No.

of f

ish

per 1

00 c

asts asala

katle

titae

Figure 42 Cast net catches (per 100 casts) at Palati downstream, 2000-2005.

Data from 2000-2003 are taken from Kaasa & Bjørtuft (2002, 2003). The flow is based on Table 1.

4.4.4 Banchare

At Banchare the fish species Nakato and Kabre were also present in the cast net catches (Table 17). Asala still dominates and Titae contributes second most in the net catch. Katle is of more significance than at the upper stations. The catches seem to follow the monsoon cycle more than at Rasnalu and Palati upstream, even if not that apparent as at Palati downstream. The density for all species seams to have had an extreme decrease from 2004 to 2005. (Figure 43).

Table 17 Cast net catches (per 100 casts) at Banchare, 2004-2005.



Garra gotyla gotyla



Asala Katle Nakato Titae Kabre

Total

June 7.9 4.9 0.8 0.5 0.0 13.4 July 10.8 6.9 0.0 1.1 0.0 18.8 August 5.4 0.9 0.0 1.3 0.0 7.6 September 5.7 0.5 0.1 0.8 0.3 7.3 October 3.0 1.4 0.0 0.3 0.0 4.6 November 2.8 3.4 0.0 0.0 0.0 6.1 December 3.3 1.1 0.0 1.1 0.0 5.5 January 1.6 0.5 0.0 0.5 0.0 2.7 February 1.6 1.6 0.0 0.0 0.0 3.3 March 2.7 1.6 0.0 1.1 0.0 5.5 April 5.5 0.5 0.0 2.2 0.0 8.2 May 9.9 1.1 0.6 2.8 0.0 13.9



0

20

40

60

80

100

120

140

160

180

July

200

0

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

1

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

2

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

3

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

4

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

5

No.

of f

ish

per 1

00 c

asts

asala

katle

titae

Figure 43 Cast net catches (per 100 casts) at Banchare 2004-2005

Data from spring 2003 are taken from Kaasa & Bjørtuft (2003).

4.4.5 Gobantar

At Gobantar the fish species diversity is higher than at the stations further upstream, with Lohari added to the list. Asala still dominates throughout the season with a peak in May, but is outnumbered by Katle in June to September. Katle density seams to peak in June-August. Titae is less prominent than at the stations further upstream. Lohari and Kabre is also represented at the station, but in low numbers (Figure 44). Table 18 Total cast net catches (per 100 casts) at Gobantar, 2004-2005.



Crossocheilus latius latius

Garra gotyla gotyla


Pseudecheneis sulcatus

Asala Katle Lohari Nakato Titae Kabre

Total

June 4.5 8.2 0.6 0.6 0.0 0.0 13.8 July 2.2 6.6 0.0 0.0 0.0 0.5 9.3 August 3.0 5.5 0.0 0.2 0.7 0.4 9.7 September 5.1 4.0 0.0 0.1 1.8 0.4 11.4 October 3.9 1.1 0.0 0.3 0.7 0.0 5.9 November 3.3 0.0 0.0 0.0 0.0 0.0 3.3 December 3.3 0.5 0.5 0.1 0.0 0.0 4.5 January 3.9 1.1 0.6 0.1 0.0 0.0 5.6 February 2.8 1.1 0.0 0.0 0.0 0.0 3.9 March 2.2 0.6 0.0 0.0 1.1 0.0 3.9 April 6.1 2.2 0.6 0.0 0.0 0.0 8.9 May 9.8 2.0 0.0 1.7 2.8 0.6 16.9



-113579

11131517192123252729313335

July

200

0

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

1

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

2

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

3

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

4

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

5

No.

of f

ish

per 1

00 c

asts

asala

katle

titae

Figure 44 Cast net catches (per 100 casts) at Gobantar 2000-2005 Data from 2000-2003 are taken from Kaasa & Bjørtuft (2002, 2003).

Figure 45 Sucker head (Garra gotyla gotyla), locally called nakato.




Figure 46 Sucker throat catfish (Pseudecheneis sulcatus), locally called labre or kabre.


4.4.6 Khimti Besi

The results for Khimti Besi are shown in Table19. The species composition and the position of the different species are similar to those at Gobantar, but a new species is added. The Buduna has not been recorded in the cast net catch at this station earlier. Densities seem to vary cyclically, influenced by the monsoon as for the other stations. Buduna, Titae and Katle densities are low, and the latter two have decreased during recent years (Figure 47). However Asala has increased during the last year, and the CPEU in the peak month has returned to the same as in May 2003.

Table 19 Cast net catches (per 100 casts) at Khimti Besi, 2004-2005.




Garra gotyla gotyla



Garra annadalei Total

Asala Katle Lohari Nakato Titae Kabre Buduna June 0.5 2.2 0.0 1.4 0.0 0.0 0.5 4.6 July 0.8 2.7 0.8 0.0 1.1 0.0 1.9 7.4 August 2.4 3.9 0.0 0.1 1.1 0.0 1.1 8.6 September 4.8 0.7 1.1 0.0 1.5 0.0 0.0 8.1 October 0.9 0.2 0.7 0.1 1.1 0.0 0.4 3.4 November 2.2 0.0 0.0 0.1 0.0 0.0 0.0 2.3 December 2.8 0.6 0.0 0.1 1.1 0.0 0.0 4.6 January 1.1 0.0 0.0 0.1 0.0 0.0 0.0 1.2 February 2.2 0.0 0.0 0.0 0.0 0.0 0.0 2.2 March 3.3 0.0 0.0 0.0 0.5 0.0 0.0 3.8 April 7.7 0.5 0.0 0.1 0.0 0.0 0.5 8.9 May 8.0 0.8 0.0 0.8 0.6 0.3 1.4 11.8



-113579

11131517192123252729313335

July

200

0

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

1

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

2

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

3

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

4

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

5

No.

of f

ish

per 1

00 c

asts asala

katle

titae

Figure 47 Cast net catches (per 100 casts) at Khimti Besi 2003-2005.

Data from spring 2003 are taken from Kaasa & Bjørtuft (2003).



4.4.7 Diurnal variation

The casts at Gobantar have been separated between 5-8 am (in the morning), and 3.30-6.30 pm (in the evening). The cast nets yielded generally more in the evening, like what was found for the previous seasons (Kaasa & Bjørtuft 2002, 2003). The June morning results (Table 20) show similar values for Asala and Katle and low densities of Lohari, Nakato. Titae and Kabre were not caught this month. The evening results (Table 20) for the same month show clearer differences: Asala is reduced by half, Katle doubled, low densities of Lohari prevail and there is no Nakato caught in the evenings. For Katle the evening CPUE values are four times as high as the morning values. Also for Asala the evening CPUE values are higher, with double the morning value. Lohari is sparse and there are no nakato cought. The next peak is in the May results where Asala peaks. The evening CPUE value for Asala is five times the morning value. A species where it is recorded higher morning values than in the evening is Titae (Table 20), and it seems that the catchability is the opposite of the pattern found in for example Asala. The total yearly CPUE is three times higher in the morning for Titae. The sum of the yearly CPUE is roughly 40 percent higher for the evening catches (Table 20). Table 20 Cast net catches (per 100 casts) at 5-8 am (morning) and 3.30-6.30 pm (evening) at

Gobantar, 2004-2005. Schizothorax plagiostomus



Garra gotyla gotyla



Asala Katle Lohari Nakato Titae Kabre

Total

am pm am pm am pm am pm am pm am pm am pm

June 1.8 3.4 1.5 7.9 0.4 0.4 0.3 0.0 0.0 0.0 0.0 0.0 4.0 11.7

July 1.5 1.5 1.5 5.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.7 3.0 8.1

August 1.5 2.1 3.6 2.1 0.0 0.0 0.1 0.1 0.6 0.2 0.0 0.4 5.8 4.9

September 5.6 3.3 4.5 1.8 0.0 0.0 0.1 0.0 3.4 0.7 0.0 0.4 13.6 6.2

October 1.5 4.0 0.9 0.4 0.0 0.0 0.1 0.2 0.7 1.1 0.0 0.0 3.1 5.6

November 1.1 5.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.1 5.5

December 3.3 3.3 0.0 1.1 0.0 1.1 0.0 0.1 0.0 0.0 0.0 0.0 3.3 5.5

January 1.1 5.5 2.3 0.0 0.0 1.1 0.0 0.1 0.0 0.0 0.0 0.0 3.4 6.7

February 0.0 5.6 0.0 1.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6.7

March 3.3 1.1 0.0 1.1 0.0 0.0 0.0 0.0 2.2 0.0 0.0 0.0 5.6 2.3

April 5.5 5.6 0.0 3.4 0.0 1.1 0.0 0.0 0.0 0.0 0.0 0.0 5.5 10.1

May 1.5 7.9 0.8 1.9 0.0 0.0 0.0 2.3 1.9 1.1 0.4 0.0 4.5 13.2

Total 27.7 48.8 15.1 26.7 0.4 0.4 0.6 2.8 8.8 3.1 0.4 1.5 52.9 81.0

The relationship between the CPUE values of Asala and Titae varies through the year, from relatively similar figures in September and December to total dominance of Asala in October/November and March/April. Katle draws a high peak in June-August, before almost vanishing. Figure 48 (morning) and 49 (evening) include data since 2000, and present thus periods of five years. The trend of generally higher CPUE values in the evening remains clear.



-113579

11131517192123252729313335

July

200

0

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

1

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

2

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

3

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

4

Sep

tem

ber

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

5

No.

of f

ish

per 1

00 c

asts asala

katle

titae

Figure 48 Cast net catches (per 100 casts) at Gobantar, at 5-8 PM from July 2000 to August 2003

and 3.30-6.30 PM between September 2003 and May 2005. Data from 2000-2003 are taken from Kaasa & Bjørtuft (2002, 2003).

-113579

11131517192123252729313335

July

200

0

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

1

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

2

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

3

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

4

Sept

embe

r

Nov

embe

r

Janu

ary

Mar

ch

May

July

200

5

No.

of f

ish

per 1

00 c

asts asala

katle

titae

Figure 49 Cast net catches (per 100 casts) at 5-8 AM at Gobantar 2000-2005. Data from 2000-

2003 are taken from Kaasa & Bjørtuft (2002, 2003).

The time of cast net fishing in the evening was changed from 5-8 PM to 3.30-6.30 PM from September 2003 due to security reasons. That might have affected the results, but it is still too early to conclude how much. As the results differ between the months, a longer period with the new regime is required in order to analyze the impact of the changed operational hours.



5 ANALYSIS AND DISCUSSION

The security situation in Nepal has varied during recent years with the consequence that electrofishing was not carried out in 2002, and the cast net schedule has been changed since September 2003. The work with river discharge sampling and analysis is also behind schedule. One can, however, comment upon data from cast net fishing and electrofishing as a basis to evaluate the relative development of the fish populations in Khimti. Asala is the dominating species for all stations and generally throughout the years. Katle and Titae are also common fish species almost at all stations. In the lower part of the river the species diversity is higher than in the upper part. This is a normal situation in Nepali rivers (Shreshta, J. 1994), and the same was observed in 1994, 1999 and later (IFC 1994, Kaasa and Bjørtuft 2002, 2003). At Rasnalu only five species were registered in 2004-2005, while tvelve species were registered at Khimti Besi. During the previous season five and eleven species were registered at these two stations. Some species are present in the catches only in low numbers, and if such low density species are randomly distributed their presence in the samples could also be random. To provide a basis to analyse any changes in the species composition data from cast net and electrofishing are compiled from Table 21 to Table 26 expressing the relative dominance of each species as a percentage of the samples.

At the upper station, Rasnalu, (Table 21) results from both cast net catches and electrofishing show a dominance of Asala and Titae. Asala has the highest proportion and Titae in general has about 1/3 of Asala’s share. The remaining species generally have only a low share. Cast nets which is based on a high number of samples every year have a more stable year to year share of the different spescies, compared to electrofishing with one sampling a year. Table 21 Rasnalu, composition of fish species from the total catches by means of cast nets and

electrofishing, expressed as percentages in each column. Cast net Electrofishing

Fish species Local name 1999 2000-

2001 2001-2002

2002-2003

2003-2004

2004-2005

1993-1994 2001 2003 2004 2005

Schizothorax plagiostomus Asala - 67.5 73.8 74.7 62.1 72.8 82.8 71.4 58.7 72.9 54.3

Acrossocheilus hexagonolepis Katle - 10.2 5.6 2.9 2.1 2.6 0.0 1.9 0.0 0.5 0.0

Psilorhynchus pseudecheneis Titae - 22.3 20.2 22.4 34.7 24.5 17.2 26.7 36.7 25.0 40.6

Glyptothorax trilineatus

Tel Kabre - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.6 1.6 4.8

Pseudecheneis sulcatus Kabre - 0.0 0.4 0.0 1.1 0.0 0.0 0.0 0.0 0.0 0.3

At Palati upstream results from both cast net catches and electrofishing show a dominance of Asala, Titae and Katle (Table 22). Asala has the clearly highest proportion compared to Titae and Kabre. The remaining species generally have only a low share. As at Rasnalu cast net have a more stable year to year share of the different spescies, compared to electrofishing with one sampling a year. Kabre, which is a low-density species, has not been registered during the last three years until this year. Tel Kabre was caught by means of electrofishing, and Buche Asala has not been registrered since 1999. Low densities of fish 0 to 50 mm suppose low recruitment, or perhaps escape of fry into the weir. Kaasa and Bjørtuft (2000), however, found no high loss numbers to the weir at Palati.



Table 22 Palati Upstream, composition of fish species from the catches by means of cast nets

and electrofishing, expressed as percentages in each column. Cast net Electrofishing


2001 2001-2002

2002-2003

2003-2004

2004-2005

1993-1994 2001 2003 2004 2005

Schizothorax plagiostomus Asala 35.9 59.5 75.9 73.6 75.8 70.5 89.6 51.8 68.4 76.3 83.3

Acrossocheilus hexagonolepis Katle 11.7 20.7 14.8 13.5 5.6 12.8 0.0 44.7 23.2 0.5 1.8

Psilorhynchus pseudecheneis Titae 20.7 18.2 9.3 12.9 18.5 16.2 10.4 3.5 7.4 18.8 12.2


Tel Cabre 4.1 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.5 4.3 1.4

Pseudecheneis sulcatus Kabre 6.2 1.1 0.0 0.0 0.0 0.2 0.0 0.0 0.0 0.0 1.4

Garra gotyla gotyla Nakato 0.0 0.0 0.0 0.0 0.0 0.2 0.0 0.0 0.0 0.0 0.0

Schizothorax richardsonii

Buche Asala 21.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

As at Rasnalu and Palati upstream results from both cast net catches and electrofishing show a dominance of Asala, Titae and Katle at Palati Downstream station most years. The share of the three dominant species is very similar at Palati upstream and Palati Downastream, especially in 2005 (table 22 and 23). The remaining species generally have only a low share. Table 23 Palati Downstream, Composition of fish species from the catches by means of cast

nets and electrofishing, expressed as percentages in each column. (The composition from 1993-1994 is taken from Palati upstream)

Cast net Electrofishing Fish species Local

name 1999 2000-2001

2001-2002

2002-2003

2003-2004

2004-2005

1993-1994 2001 2003 2004 2005

Schizothorax plagiostomus asala - 62.1 79.8 81.0 72.7 73.7 (89.6) 87.4 85.0 81.8 79.8

Acrossocheilus hexagonolepis katle - 22.2 9.3 6.6 2.7 10.8 - 0.0 5.0 3.1 1.1

Psilorhynchus pseudecheneis titae - 13.6 10.9 11.9 24.7 14.5 (10.4) 11.7 6.7 9.4 13.7

Glyptothorax trilineatus tel cabre - 0.8 0.0 0.0 0.0 0.0 - 1.0 0.0 3.6 3.3

Pseudecheneis sulcatus kabre - 0.8 0.0 0.0 0.0 1.0 - 0.0 0.0 0.0 2.2

Garra gotyla gotyla nakato - 0.0 0.0 0.4 0.0 0.0 - 0.0 0.0 0.0 0.0

Crossocheilus latius latius lohari - 0.4 0.0 0.0 0.0 0.0 - 0.0 0.0 0.0 0.0

Nemacheilus beavani masani - 0.0 0.0 0.0 0.0 0.0 - 0.0 3.3 0.0 0.0

Nemacheilus rupicola sime - 0.0 0.0 0.0 0.0 0.0 - 0.0 0.0 0.5 0.0

Even though the share between the species have been relatively stable at Palati Downstream and Palti Upstream the cast net results showed significant differences between the two stations during the previous seasons, with higher CPUE values at the upper station (Kaasa & Bjørtuft 2003). Even if the stations lie close to each other, there might be natural differences between them that could cause quite different catch numbers and CPUE values. One important difference between these two stations is the flow conditions during the low flow season - due to hydropower regulation. The station at Palati Downstream has been fenced and thus protected from fishing and the illegal use of poison.



During the 2004-2005 season the CPUE values have generally been higher at all stations than during previous years. The increase is less obvious at Palati Downstream than at the reference stations. In the 2000-2001 season the overall CPUE value was almost the same at Palati Downstream and Rasnalu, the control station. In the three following seasons the values were considerably higher at Palati downstream than at Rasnalu before this year when the values are almost as in the 2000-2001 season. Regarding the estimated densities upstream and downstream of the weir at Palati, the density is halved at the downstream point. Values at Palati Downstream seem to follow the monsoon cycle clearer than at the upstream stations, with more fish caught at high water discharges, and with hardly any catch from December to February. The estimated density of Asala at Palati downstream shows an increase for Asala over 50 mm and a stable situation when combining all sizes. Asala is reported to spawn twice a year in Nepal, during September/October and March/April, with the autumn as the best season for spawning (Rai et al. 2002). Local fishermen and fish biologists in BPC have reported that this is the case also in Khimti. At Banchare the status of species composition is confirmed, Asala dominating, and more Katle than Titae (Table 24). Of species fewer in number Nakato and Kabre were found in the cast nets and some by electrofishing. Relatively more Katle taken by means of cast nets than by electrofishing can be noticed. The results show generally lower CPUE values from cast nets and higher estimated fish densities from electrofishing. Table 24 Banchare, composition of fish species from catches by cast nets and electrofishing in

2003-2005, expressed as percentages.

Cast net Electrofishing Fish species Local

name 1999 2000-2001

2001-2002

2002-2003

2003-2004

2004-2005

1993-1994 2001 2003 2004 2005

Schizothorax plagiostomus Asala - - - 53.9 59.4 65.1 - - 64.5 71.4 78.5

Acrossocheilus hexagonolepis Katle - - - 34.2 24.3 20.8 - - 14.5 15.8 14.7

Psilorhynchus pseudecheneis Titae - - - 9.9 13.9 11.5 - - 12.5 10.3 6.0

Pseudecheneis sulcatus Kabre - - - 2.0 1.0 0.4 - - 0.7 0.0 0.4

Garra gotyla gotyla Nakato - - - 0.0 1.5 2.2 - - 0.0 0.0 0.0

Nemacheilus rupicola Sime - - - 0.0 0.0 0.0 - - 7.9 2.6 0.4

At Gobantar as the upper stations asale, katle and titae are the dominating species (Table 25). The percentage distribution of asala shows a stable lable regarding the cast net catches, but a decreasing tendency from 1993-1994 to 2005 regarding the electrofishing results (Table 25). The electrofishing results also indicates that katle have got a stronger position during that period, but this is not tru for the cast nest results. Titae seams to contribute with a stable low share. At Khimti Besi the percentage of asala seems stable, with some variation between the two last years for the other species, especially katle and titae (table 26). Gurde was caught in 2003, chuche asala caught in 2004 and one gardi caught in 2005. In 2005 buduna was present for the first time with an important share. Regarding the different position of nakato, lohari, masani, sime it seams as the estimation metods give different estimates.



Table 25 Gobantar: Composition of fish species from the catches by means of cast nets and

electrofishing, expressed as percentages in each column. Cast net Electrofishing


2001 2001-2002

2002-2003

2003-2004

2004-2005

1993-1994 2001 2003 2004 2005

Schizothorax plagiostomus Asala 42.4 55.7 52.8 41.4 46.8 47.6 82.1 68.2 62.7 55.2 51.9

Acrossocheilus hexagonolepis Katle 0.7 25.3 36.5 44.6 37.3 34.6 15.8 9.0 18.6 22.1 24.5

Psilorhynchus pseudecheneis Titae 2.4 7.0 4.2 5.7 6.4 4.9 0.0 13.4 5.9 1.2 9.0


Tel cabre 7.2 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Pseudecheneis sulcatus Kabre 0.3 6.5 2.8 2.6 0.4 2.7 2.1 4.5 2.5 0.6 0.0

Garra gotyla gotyla Nakato 0.3 3.2 2.1 2.6 8.6 8.1 0.0 1.5 3.0 2.9 3.6

Crossocheilus latius latius Lohari 30.0 1.4 1.7 3.1 0.4 2.2 0.0 1.0 0.0 2.9 0.0

Nemacheilus beavani Masani 5.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.4 9.3 2.7

Nemacheilus rupicola Sime 0.3 0.0 0.0 0.0 0.0 0.0 0.0 2.5 3.8 5.8 4.5


Buche asala 0.3 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.4

Labre 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.5

Table 26 Khimti Besi, composition of fish species from the catches by means of cast nets and

electrofishing in 2004, expressed as percentages in each column. Cast net Electrofishing


2001 2001-2002

2002-2003

2003 to 2004

2004-2005 1993-

1994 2001 2003 2004 2005

Schizothorax plagiostomus Asala - - - 41.2 45.6 44.8 - - 53.3 48.2 46.3

Acrossocheilus hexagonolepis Katle - - - 35.2 21.1 20.1 - - 5.7 9.6 6.1

Psilorhynchus pseudecheneis Titae - - - 8.5 15.8 11.0 - - 15.9 9.0 21.1

Labeo dero

Gurde - - - 0.6 0.0 0.0 - - 0.4 0.0 0.0

Pseudecheneis sulcatus Kabre - - - 0.6 0.6 0.5 - - 4.4 0.0 0.0

Garra gotyla gotyla Nakato - - - 6.7 13.5 9.6 - - 0.4 2.4 0.0

Crossocheilus latius latius Lohari - - - 7.3 3.5 4.6 - - 0.0 0.0 0.0

Nemacheilus beavani Masani - - - 0.0 0.0 0.0 - - 7.5 6.6 6.4

Nemacheilus rupicola Sime - - - 0.0 0.0 0.0 - - 11.9 18.7 13.1


Buche Asala - - - 0.0 0.0 0.0 - - 0.0 3.6 6.4

Schizothorax progastus

Chuche Asala - - - 0.0 0.0 0.0 - - 0.0 1.2 0.0


Tel Cabre - - - 0.0 0.0 0.0 - - 0.4 0.6 0.0

Gardi - - - 0.0 0.0 0.0 - - 0.0 0.0 0.3

Garra annadalei Buduna - - - 0.0 0.0 9.6 - - 0.0 0.0 0.0

The relatively stable CPUE values recorded by cast net fishing and the fish length frequency from the electrofishing catches, together with increased catch mortality during the low flow season, could indicate that during the monsoon the river is migrated by fish from downstream areas.



The importance of the use of poison in fish catching, is belived to have a great affect on the fish density in Khimti Khola: in a 135 m² area a total of 674 fish with a weight of 44 kg was recorded. In 2005 fortyeight different places were used when fishing with poison (Rakesh 2006). The affected areas are especially downstream of the Palati weir, where there is less water and it is thus easier to make the poisoning effective. However, the use of poison in the river upstream Palati weir is not studied.



6 CONCLUSIONS

• Asala is the dominating species for all stations and generally throughout the years. Katle and Titae are also common fish species almost at all stations.

• In the lower part of the river the species diversity is higher than in the upper part.

• Cast nets which is based on a high number of samples every year normally have a more stable year to year share of the different spescies, compared to electrofishing with one sampling a year.

• Some differences in the species composition and in the CPUE values are recorded. At

Palati the differences between upstream and downstream the intake weir is significant in 2004-2005. The density estimated by electrofishing shows double the density upstream, and low recruitment downstream. However, due to variation both in estimation results and annual fluctuations, more and longer time series are needed to conclude.

• The most striking environmental change between the two stations is the discharge during

the low flow period due to hydropower regulation.

• The number of fish species registered is lower in 2005 than previous years at some of the stations. It is important to bear in mind, however, that the species are all low-density species and the catchability is low.

• An increased activity concerning use of diversion and use of poison to catch fish in Khimti

Khola is recorded, however more studies are needed both downstream and upstream of Palati weir to conclude the magnitude of the effects. This illegal activity is harmful to the fish population, and it kills adults, fry and invertebrates in the affected areas.

• The relatively stable CPUE values recorded by cast net fishing and the stable fish length

frequencies from the electrofishing catches, together with an increased catch mortality during low flow season, could indicate that during the monsoon the river is migrated by fish from downstream areas.

• Even if Khimti Khola is physically changed due to hydropower regulation, it is so far not

easy to see the overall alterations in the fish population that could be expected. Nevertheless there are some changes in the records that might be a result of the hydromorphological changes.

• The time of cast net fishing in the evening was changed from 5-8 PM to 3.30-6.30 PM from

September 2003 due to security reasons. This seems to have affected the results, and the population size might be higher than estimated after the time shift. It is, however, still too early to conclude how much. As the results differ between the months, a longer period with the new regime is required in order to analyze the impact of the changed operational hours.



7 REFERENCES

Abbas, B. M., 1982. The Ganges Water Dispute. University Press Limited, Bangladesh. (Not seen, reference taken from Rajbanshi (2002), see below).

Bohlin, T.; Hamrin, S.; Heggberget, T.G.; Rasmussen, G.; Saltveit, S.J. 1989. Electrofishing - Theory and practice with special emphasis on salmonids. Hydrobiologia 173: 9-43.

Garcia & Associates 2002. Khimti Hydroelectric Project. Independent Engineer’s 2001 Review of Revised 2001 Khimti Khola Fish Ecology Annual Report, Environmental Compliance Matrix, ToR and other Materials Related to the Khimti Hydroelectric Project.

Gurung, T.B. 2002. Fisheries and Aquaculture Activities in Nepal. Aquaculture Asia, vol. VII (4): 39-44.

IFC 1994: Supplementary Environmental Assessment of Khimti Khola Hydroelectric Project, SEA, Norconsult, BPCH.

Junge, C.O. & Libosvarsky, J. 1965. Effects of size selectivity on population estimates based on successive removals with electrical fishing gear. Zool. listy 14: 171-178

Kaasa, H.2000: Khimti Khola Hydropower Project - Fish Ecology: Report 1999, Statkraft Engineering Report, 15 pp.

Kaasa, H. & Bjørtuft, S.K. 2002: Khimti Khola Hydropower Project. Fish Ecology. Annual Report 2001, Statkraft Grøner. 44 pp.

Kaasa, H. & Bjørtuft, S.K. 2003: Khimti Khola Hydropower Project. River Ecology - Annual Report 2003, Statkraft Grøner. 53 pp + annex.

Payne, A. I., Sinha, R., Singh, H.R. & Huq, S. 2003. A review of the Ganges basin. Its fish and fisheries. 30 pp. http://www.lars2.org/unedited_papers/unedited_paper/Payne%20Ganges%20review.pdf

Rajbanshi, K.G. 2002. Zoo-geographical distribution and the status of coldwater fish of Nepal. pp. 214-239 in: Petr, T.; Swar, D.B. (eds.) 2002. Cold water fisheries in the trans-Himalayan countries. FAO Fisheries Technical Paper. No. 431 Rome, FAO. http://www.enaca.org/NACA-Publications/Transhimalayanfisheries.pdf

Rai, A.K., B.R. Pradhan, S.R. Basnet and D.B. Sawr. 2002. Present status of snow trout in Nepal. In: Petr, T.; Swar, D.B. (eds.) 2002. Present status of the snow trout in Nepal. pp. 206-213 in: Petr, T.; Swar, D.B. (eds.) 2002. Cold water fisheries in the trans-Himalayan countries. FAO Fisheries Technical Paper. No. 431 Rome, FAO. http://www.enaca.org/NACA-Publications/Transhimalayanfisheries.pdf

Rakesh, Y. 2003. Fishing activity during low flow season in Khimti Khola with focus on river diverting and use of poison. BPC memo. 3 pp.

Rakesh, Y. 2006. Fishing with poisoning in Khimti Khola. BPC Hydroconsult. 8 pp.

Sharma, C.M. and Shrestha, J. 2001. Fish diversity and fishery resources of the Tinau River, Western Nepal. In: Jha, P.K., Baral, S.R., Karmacharya, S.B., Lekhak, H.D., Lacoul, P. and Baniya, C.B. (eds): Environment and Agriculture: Biodiversity, Agriculture and Pollution in South Asia, 2001, pp. 78-83.

Shrestha, J. 1994. Fishes, Fishing implements and methods of Nepal. Bangkok Publication.

Shrestha, T.K. 1994. Fisheries Resources of Khimti River. Report to BPC.

Shrestha, T.K. Conservation and Management of Fishes in the Large Himalayan Rivers of Nepal. 19 pp. http://www.lars2.org/unedited_papers/unedited_paper/Shrestha.pdf



Shrestha, T.K. 2002. Cold water Fisheries Development in Nepal. pp. 47-58 in: Petr, T.; Swar, D.B. (eds.) 2002. Cold water fisheries in the trans-Himalayan countries. FAO Fisheries Technical Paper. No. 431 Rome, FAO. http://www.enaca.org/NACA-Publications/Transhimalayanfisheries.pdf

Zippin, C. 1956. An evaluation of the removal method of estimating animal populations. Biometrics 12: 163-169.

Zippin, C. 1958. The removal method of population estimation. J. Wildl. Management 22: 82-90.

ANNEX 1 HOLA HYDROPOWER PROJECT Terms of Reference ANNUAL REPORT 2005

SWECO Grøner AS F:\Data\PDM\Annual Report\2062-63\AMR\060313 Final report Khimti 2005 rev 13032006.doc PAGE 1 OF 13

ANNEX 1

Himal Power Limited KHIMTI I HYDROPOWER PROJECT

TERMS OF REFERENCE (TOR)

River Ecology Study Programme

1) INTRODUCTION Khimti I Hydropower Project is a ‘Run-of-the-River’ type of hydroelectric plant with an installed capacity of 60MW. The project is located in central Nepal, about 100 km due east of Kathmandu. The power plant has been in commercial operation since July 2000. The primary responsibility for all environmental monitoring and mitigation rests with HPL as the project owner and operator and they have instigated this study as part of their efforts to fulfil this responsibility. The study was started in July 2000 but was subject to a delay of one year. The study is scheduled to continue until completion in July 2006. 2) THE MAIN OBJECTIVES The primary function of this TOR shall be to describe a 5-year monitoring programme with intention to mitigate or give a satisfactory solution to environmental issues and challenges that have turned up so far in the project related to the river ecology of Khimti Khola. At the end of the 5-year study programme the consultants shall work out recommendations for the long-term programme as part of the Final Report. The environmental studies and findings during the EIA study, during the construction period from 1993, and the operating phase have generated both knowledge and challenges. The following documents shall give the status: a. IFC 1994: Supplementary Environmental Assessment of Khimti Khola Hydroelectric Project, SEA, Norconsult,

BPCH.

b. HPL 1996: Khimti 1 Hydropower Project. Environmental Mitigation and Monitoring Plan

c. HPL Fisheries Management Plan, Section 7 of HPL’s Health, Safety and Environment Policy Manual.

d. Kaasa, H.2000: Khimti Khola Hydropower Project - Fish Ecology: Report 1999, Statkraft Engineering Report, 15 pp.

e. Kaasa, H. 2002: Khimti Khola Hydropower Project , Fish Ecology. Annual Report 2001, StakraftGrøner. 44 pp

f. Kaasa, H. & Sandsbråten, K. 2001: Khimti Khola Hydropower Project. Field studies January and February 2001. Fish ecology and hydrology. Memo Statkraft Grøner 27.03.2001. 2 pp.

g. Garcia & Associates 1999. Khimti Hydroelectric Project. Independent Engineer’s 1998 Annual Environmental Review.

SWECO Grøner AS F:\Data\PDM\Annual Report\2062-63\AMR\060313 Final report Khimti 2005 rev 13032006.doc PAGE 2 OF 13

h. Garcia & Associates 2000. Khimti Hydroelectric Project. Independent Engineer’s 1999 Annual Environmental

Review.

i. Garcia & Associates February 2002. Khimti Hydroelectric Project. Independent Engineer’s Final Environmental Inspection Report No. 5.

j. Garcia & Associates, August 8, 2002, GANDA. Rewiew of Revised 2001 Khimti Khola Fish Ecology Annual Report, Environmental Compliance Matrix, TOR and other Materials Related to the Khimti Hydroelectric Project.

k. Environmental Compliance Matrix Approved by DoED, Nepal as of 13. June 2002 The requirement set forth in the above mentioned documents and the knowledge obtained from them shall be used in designing the 5 year study program. The main objectives of the study programme shall be: 1. Fish ecology, monitoring and impact mitigation 2. Monitoring of hydrology, erosion, sediment transportation 3. Monitoring of water quality 4. Impact on Fishermen 5. Awareness Brochure 3) RIVER ECOLOGY STUDY PROGRAMME REQUIREMENTS The programme content shall take due account of the agreements of HPL with His Majesty’s Government of Nepal and lenders, the legislations in Nepal and the requirements of the investment banks. The environmental monitoring programme shall be accomplished by using internationally accepted methods and qualified staff sufficient to secure international acceptance of the results. Further details are given in Section 6 of this Terms of Reference. The knowledge obtained by the programme shall be utilised to find solutions to the exposed challenges that satisfy the requirements laid down in the licence. Furthermore, documentation of the work carried out under the programme and of the results, conclusions and recommendations shall be presented in reports as prescribed in Section 8. This TOR provides a specific description of technical topics, parameters to be measured, fish sampling localities, frequency of measurements, possible corrective actions, and monitoring and reporting procedures. 4) DURATION OF THE STUDY PROGRAMME This study shall be active for 5 years from the date of the commercial operation of the power plant. Due to one year of inactivity, the study shall be extended to 2006. The final report, issued according to the Programme Schedule attached to this Terms of Reference, shall be issued after 5 active years of study, and shall give recommendations as to the content and extent of further long-term study requirements. In the event that significant impacts are found and substantiated before the end of the Programme Schedule compensatory measures shall be implemented at an earlier stage in the programme.


SWECO Grøner AS F:\Data\PDM\Annual Report\2062-63\AMR\060313 Final report Khimti 2005 rev 13032006.doc

5) PROGRAMME MANAGEMENT HPL shall make use of international and local experts to carry out the programme activities. The monitoring programme shall be according to the main elements and timings as indicated in the attached Programme Schedule and as detailed in Section 6 of this Terms of Reference. The technical details and timing of the activities of the Programme shall be adjusted by the international consultant during the period of the study in order to accommodate necessary improvements. The monitoring programme, as per pt 6.4, shall be carried out by a local consultant that is familiar with the project. Although the local consultants shall be under the professional leadership of the international expert, they shall be contracted directly by HPL due to practical reasons. The choice of local expert shall be subject to the approval of the international consultant, who shall give their professional approval for the selection of the local consultant before HPL signs a contract with the local consultant. The professional and scientific demands expressed in the contract between HPL and the local consultant shall be subject to the approval of the international consultant. The intention is that as much as possible of the consultancy work, within the range of scientific confidence, shall be performed by local Nepali experts. HPL, DoED and the investment banks involved are responsible to select an impartial international consultant who can review the environmental activity. 5.1 International Consultant To fulfil the programme objectives, a professional environmental expert of international level shall be engaged as the International Consultant. The expert shall be familiar with the ecology in Nepali rivers. It is preferable that the international consultant has knowledge of Nepali culture as well as experience from arranging and running scientific and technical studies in Nepal. 5.2 Nepali Consultant In co-operation with HPL the international consultant shall select a local Nepali consultant that can give assistance to carry out the field operations, and do the current continuous field work, data recording and write progress reports and assist in the preparation of annual scientific reports to the international consultant. The local consultant should have technical staff and equipment sufficient to handle the required works. If necessary the international consultant shall give practical training to the Nepali consultant.



6) TECHNICAL CONTENT OF THE FIVE-YEAR PROGRAMME The scientific requirements of the fieldwork programme is described in brief below: 6.1 Fish ecology and impact mitigation 6.1.1 Background The impact on the fish population in Khimti Khola has been monitored through registration of fish densities, species composition and drifting fish in three locations: Rasnalu, Palati and downstream of Gobantar. The sampling programme was designed to enable a comparison of the findings with those of the previous programme (EIA and SEA). Cast nets have shown good ability to capture different fish species, and the local fishermen have long tradition in practising this method. Use of cast nets is therefore considered a convenient and sustainable methodology to monitor fish species composition (IFC 1994). The method of electric fishing was established by IFC in 1993. To have good comparable data, the same method was used in subsequent projects. Electric fishing is recommended used during the low flow season. To sample data from drifting fish a method using small meshed drift nets was used in 2000 in the river at Palati and in the outlet from the sedimentation basin. The method is described in Kaasa 2002. The sampling programme shall now be extended to a total of five locations as detailed in the following. 6.1.2 Effect of the hydropower scheme on the fish population The impact on the fish population in Khimti Khola shall be monitored through registration of fish population densities, species composition, population size and drifting fish at five locations: Rasnalu, Palati, Banchare,downstream of Gobantar and Khimti Besi. Three of the sampling stationes are identical with former used stations. The two new stations are Banchare, situated between Palati and Gobantar, and Khimti Besi, close to where Khimti river flow in to Tama Koshi. This ToR describes the requirements and the basic methodology to be used to achieve them. These shall be further elaborated by the international consultant who shall make a detailed programme proposal in cooperation with HPL. a) Fish species composition, densities and population estimates before and after river regulation.

Methodology: Electrofishing and cast net as used by IFC and as described in Annex 1 should be the basic sampling method: Species composition: Electrofishing and cast net Species densities (low flow season): Electrofishing Rough population estimates: Calculations based on fish densities, (low flow season) habitat availability, wet periphery (ref. 6.2.2).



Schedule for new measurements:

1. Electrofishing once a year at five locations: during the clear water period, and preferably in February/March.

2. Fishing with cast nets during the period from pre-monsoon to post-monsoon, with sampling every second week at five locations with intensive efforts at each location. The rest of the year, sampling shall be undertaken every second month.

b) Habitat availability and classification (mapping and registration of habitat classes according to

habitat type numbers) as a basis for recording changes in habitat conditions due to the project.

Methodology: Habitat mapping either manually or by study of aerial photos with quality assurance by field inspections in selected locations. The exact detailed methodology will be chosen by HPL in cooperation with the international consultant.

c) An assessment of changes in fish production in the affected area shall be made on the basis of

the population estimates from section 6.1.2 a) above. Results shall be compared with data from before river regulation and from areas upstream of the intake weir. An assessment shall also be made as to whether changes have occurred in fish catches over the year cycle since the introduction of river regulation.

Methodology:

Analysis of CPUE (fish catches) shall be made by means of results from cast net fishing along the river from Hadumpa to Gobantar. The conditions before and after the introduction of river regulation shall be assessed and the results from electrofishing and cast net fishing shall be compared and combined as part of the scientific analysis.

6.1.2 Fish entrapment in the tunnel inlet Results from entrapment studies have shown that some young fish enter the tunnel system. There is no registration of mature fish being entrapped. The scientific programme shall address the following issues: a) Are mature fish exposed to entrapment in the tunnel? If so how are the local fish populations

affected? b) How is the recruitment from present species downstream of Palati compared to the river

upstream of Palati? c) Will the entrapment of the young fish affect the river population?

Methodology: The international consultant shall employ suitable methodology in order to adequately address the issues, and shall develop a proposal that considers at least the two following methods:

1. Use of a device such as a drift net with rectangular opening to establish if mature fish are

entering the tunnel from the sedimentation chamber. This device must be able to catch fish close to the bottom and walls of the sedimentation basin as well as in the rest of the flow cross-section.



2. Carry out tagging experiments with mature fish in the Palati area to see if they are entering

the tunnel. 6.1.3 Monitoring fish migration across the intake weir The project results so far seem to indicate that the river has several waterfalls downstream of Palati that represent a far greater physical barrier than that of the weir at Palati. Consequently knowledge on the extent of low-flow season upstream fish migration before the construction of the weir shall be obtained. The main challenge to the fish seems to be crossing the intake weir on its way upstream during periods of low flow. An assessment of fish migration over the weir shall therefore be made employing the methodology described below. Methodology: 1. Historical upstream fish migration shall be assessed by interviewing local fishermen and local

fishery experts etc. 2. Current fish migration shall be assessed by tagging a group of fish of different species from the

Palati area. The fish shall be released downstream of the weir area during low flow conditions and their progress upstream shall be observed. The international consultant shall prepare the exact tagging programme.

6.1.4 Mitigating Measures Mitigation of Entrapment If the main findings of section 6.1.2 show a significant and unacceptable impact on the fish population, appropriate measures shall be developed to prevent tunnel entrapment of fish. These may include physical (technical) interventions or other suitable approaches based on consultations with local fishery experts, DoED and the international consultant. Mitigating Loss of Fish Production Documented significant loss of fish production shall lead to measures designed to mitigate the situation. To the extent possible, such measures shall be designed to take into account the results of consultations with local stakeholders (affected fishermen), local fishery experts and DoDE. Typical measures may include:

a) Preparation of information strategies and management plans that reduce the catch mortality along the Khimti downstream of Palati during the low flow season.

b) Recommendations for a pilot project for local fish farming activity based on local species and local natural fish fry from the river (ref. IFC report 1994).

c) Fish improvement through ecologically based measures in the low flow season. Herby strengthening the lowest step in the nutrient chain. Keywords in this respect will be the energy spiral and nutrient availability.

In the case of implementation of any of the above measures, the international consultant shall prepare proposals to address or carry out point a) and b) measures. Preparations shall be made for



point b) measures as soon as the scientific staff identify any fish population decrease. Point c) measures need to be developed and tested before implemented on a large scale. After consultation with DoED, HPL shall take the final decision on the implementation of all measures. 6.2 Hydrology The international consultant shall propose a data collection programme based on the following points. 6.2.1 River discharge Diversion of water from the river system due to hydropower production causes changes in the hydrological regime of the river. For description of downstream hydrology there should be two points of discharge measurement:

a) At the weir b) Just upstream of the confluence of Khimti Khola with Tama Koshi.

Measurements at these stations should give estimates of inflow from the residual sub-catchments. For control of similarity in inflow from the various sub-catchments downstream of the intake there campaign discharge measurements should be undertaken at the major tributaries. Two types of measuring methods should be considered:

a) Continuous registration with the help of a recording limnigraph (water level recorder) or other form of recording apparatus.

b) Manual observations on a gauge and flood level tubes. River discharge measurements shall be used to control given minimum flow requirements and to describe changes in the hydrological regime caused by this diversion. Records of daily discharge at both stations should be reported in data files and documented in an annual report. 6.2.2 Wetted Periphery During the dry season most of the water is routed through the power station and this causes aggregation of low flow conditions downstream of the intake site. This may cause ecological impacts. Changes in wetted periphery due to such aggregated low flow conditions shall be obtained. The wetted periphery shall therefore be measured at the same locations where discharge is measured. As a basis for the estimate of changes in wet periphery downstream of the intake site the following methods shall be considered: a) Aerial photography, which can be geo-referenced to digitise the water line as a basis for

calculation of the reduction in wet area. b) Manual measurement of cross-sections under various flow conditions and at various locations

along the river.



6.2.3 Erosion and Sediment Transport Reduced sediment transport capacity due to reduction in river discharge may cause increased sedimentation in the affected river reach. Aggregated low flow conditions may increase bank instability in low flow seasons and cause increased erosion. 6.2.4 Groundwater Conditions Reduced river discharge may have an impact on ground water conditions in the affected area. An evaluation shall be made on the basis of scientific knowledge to assess if this is an issue which needs to be dealt with by HPL. 6.3 Water Quality The water quality analysis programme aims to describe changes due to the hydropower development with special relation to the health of the local people, but also to describe the normal water quality situation. The international consultant shall ensure that the water sample collections are made to appropriate scientific standards. The following parameters are to be measured: • pH • Conductivity • Turbidity • Alkalinity/acidity • Nitrate-N • Phosphate • Coliform, total • Coliform, faecal • Gardia, worms and larvae • Dissolved Oxygen Sampling stations: a. Above the intake weir at Palati b. 1 km downstream the intake weir at Palati c. Upstream the confluence of Haluwa kohla d. Khimti Besi Schedule: Sampling at all 4 locations two times a year; end of January in a period without rainfall and middle of July throughout the entire project period. The sampling frequency may be increased if found scientifically necessary. A qualified laboratory in Nepal, approved by the international consultant, shall be selected for carrying out the water sample tests. The local consultant shall be responsible for the management of the laboratory tests. 6.4 Impact on Fishermen A study shall be carried out to assess the impact on the fishing community along Khimti Khola. This study shall also quantify the fish harvest in Khimti Khola and research on the alternative jobs



needed for the fishermen, their nutritional habit and the benefit of the rural development on their livelihood in case there is any major impact on their harvest. A local consultant shall carry out this work. The duration of the study shall be one year. HPL and the international consultant shall jointly approve the study proposal. The findings of the study shall be included as an appendix to the first Annual Report after completion of the study. Remedial measures should be considered if and as soon as significant impacts are detected. In consultation with DoED, HPL shall select relevant actions to be taken. Methodology: Public consultations performed by local social experts. 6.5 Awareness Brochure An awareness brochure shall be prepared to try to stop illegal fishing along Khimti Khola. It shall be distributed to the local people living in the vicinity of Khimti Khola. The international consultant shall give technical input to HPL for the preparation of the brochure. 7) TECHNICAL CONTENT OF LONG-TERM PROGRAMME This part of the TOR gives an outline of the future long-term programme. The 5-year programme should consider and review the objectives and the continuity issues. 7.1 Fish Ecology • Register fluctuations in the fish population and fish production, concerning different species

along the river. • Evaluate mitigation measures 7.2 Hydrology • Long-term flow measurements • Erosion and sediments • Groundwater Conditions 7.3 Water Quality • Low intensity water quality programme 7.4 Socio-economy • Local society development with focus on affected fishermen or other affected

parties/stakeholders. • Evaluate mitigating activities 7.5 Adjustments of Monitoring Programme and Mitigation Strategy • Benchmarking criteria • Nepali and international standards



8 REPORTS AND MEETINGS 8.1 Progress Reports The international consultant shall submit progress reports to HPL, maximum 20 pages, two times a year, one at the end of May and one at the end of November each year. The reports shall contain information about the objectives; Fish biology, Hydrology, Water quality and Socio economy. These reports shall describe the status according to plan and economy, scientific challenges, description of unforeseen difficulties, and other information relevant to the HPL’s programme management. The consultants are responsible to address programme modifications if scientifically needed. Comments received from HPL or other affected parties to the reports shall be evaluated and, to the extent appropriate, incorporated in the study programme. The local consultant shall submit biannual progress reports in the English language to HPL with copy to the international consultant by the 10th of May and the 10th of November each year. The local consultant’s progress reports shall cover all aspects of his activity under the programme. 8.2 Annual Reports With the exception of the 1st Annual Report, which shall be issued by 1 October 2003, the Annual Report shall be submitted within 4 months after the end of the yearly termination of fieldwork. Not later than 30th April each year. The annual report shall contain results from the previous year’s studies, a short benchmarking according to baseline studies by the time of commercial operation, and a subsequent evaluation of the programme with discussion of potential programme changes to be done. The report shall give a clear description of methods with documented analysis, findings and discussions, and shall be of international scientific standard. 8.3 Programme Meetings HPL shall, if needed, arrange a yearly meeting to co-ordinate the consultancy activity. The meeting shall be arranged upon request from HPL and the subjects adapted to the current situation. The international and local consultant shall also, according to their profession, assist HPL in matters concerning public relations and meetings with the authorities. The meetings shall normally be coordinated with the international consultant’s activity in Nepal. 8.4. Draft Final and Final Reports The draft Final Report shall be submitted to the Client within 6 months of the termination of the 5-year programme. The report shall be of international scientific standard, and shall contain a full review of the findings during the study period, and a benchmarking according to the baseline situation. All objectives shall be included as well as experience from programme management and other topics relevant to the client. The Final Report shall be submitted 1 month after the consultant has received comments on the draft Final Report from HPL. 8.5 The Long-term Programme At the end of the 5-year programme the consultants shall elaborate recommendations for the long-term programme as part of the Final report.



9. SCHEDULE The time frame of the study programme is dependent on the field investigations. There should be enough collected data from different seasons to adequately address the questions. The weather or season dependent fieldwork has to be prepared and carried out under the right conditions. The security situation may cause delay in the programme, but this gives no immediate permission to skip a sampling period from the programme. For the remaining period of the study up to July 2006, the following tentative schedule shall be followed. This is further illustrated in the attached River Ecology Study Programme Schedule: Start of programme: July 2000/2003 Selection of Nepali consultant: July 2003 Start of fish biology programme: July 2000/2003 Start of Hydrology programme: July 2003 Start of Study on Impact on Fishermen: August 2003 First progress report deadline: End of Nov 2003 First Annual Report, international standard 1. October 2003 (covering period 7.2001-7.2003) Second Annual Report, international standard 30. April 2004 The years following have: - First and second progress reports: By the end of May and Nov - Annual Report: 30th of April The last year in the five-year programme shall have this schedule: -Progress report deadline: End of May -Second progress report deadline: End of Nov -Final draft report deadline: End of July the year after the

termination of the fieldwork. Final Report deadline: 1 month after the consultant has received

HPL’s comments to the Draft Report.



Annex 1 METHODS Electrofishing Electrofishing shall be carried out in order to register the juvenile fish densities in the low flow season. Equipment delivered by Geomega, Norway, with a maximum voltage of 1600 V and a frequency of 80 Hz shall be used. The selected locations shall be marked and measured. The same area shall be fished three times, with an interval of half an hour. The fish species and fish length shall be recorded for each round. Densities, given as number of juvenile fish per 100 m², shall be calculated on the basis of the amount of fish captured in each of three counts, based on formulae given by Junge and Libosvarsky (1965). In general the youngest cohorts are represented by lengths less than 5 cm. As the smaller fish are generally more difficult to catch, and the results therefore are more unreliable, the densities shall be calculated separately for fish up to 5 cm and for longer fish. Electric fishing shall be carried out once a year at five locations, during the clear water period, and preferably in February/March. Cast Nets Cast nets have shown a good ability to capture different fish species, and the local fishermen are used to this fishing method. Use of cast nets is therefore considered a convenient and sustainable method to monitor the fish species composition and to form a basis for evaluation of the long-term changes in the fish population. The cast nets shall be circular with mesh size gradually decreasing from 14 mm in the centre to 17 mm in circumference. The table below shows how many meshes there shall be of a certain size at each position as counted from the centre of the net: Number of meshes from centre of cast net

Mesh size in mm

first 8 40 next 3 35 next 8 32 next 2 30 next 2 27 next 2 25 next 2 24 next 7 23 next 9 21 next 12 18 next 25 17 next 11 17 Between 105 and 110 metal weights, each of 40 g , shall be attached to the circumference of the cast net.



For all casts the parameters cast number, date, time, weather condition, and water colour shall be recorded. When fish are caught, species, length, weight, and sexual maturity shall also be recorded. The field workers shall be instructed to find suitable stations to carry out the work, with 90-100 casts per station of a distance of up to 1.5 km. For ease of comparison the results shall be presented as number of fish per 100 casts, thus showing the catch per unit effort (CPUE). Fishing shall be carried out with cast nets during the period from pre-monsoon to post-monsoon, with sampling every second week at three locations with high effort on each location. For the rest of the year sampling shall be undertaken every second month.

himal power limited project · hpl is continuing. the programme consists of all aspects of fish...

Documents