Sand mining: as an adaptation measure to climate change induced disaster in Chitwan District of Nepal

Prof. Dr. Hari K. Shrestha Nepal Engineering College

(email: hari@nec.edu.np)

Inception workshop on Developing regional collaboration in river basin management in response to climate change

Himalaya Hotel, Lalitpur February 27, 2013

Organized by:

• Climate Change: – too hot, too cold, – too much, too little, – too early, too late

• Adaptation: – change position/action to thrive – convert potential problem into resource

• Sand Mining: resource problem resource problem • Chitwan District:

– Un/mis-management: resource becomes problem

Climate change

Once upon a time

Improper management Adaptation

Better management

Chitwan

Past threats floods

4

Event village Comments CauseFLOOD KHAIRAHANI Jun-71 A bridge over Khaireni was flooded. OTHERFLOOD PIPLE Sep-74 1000 m of highway was flooded and destroyed. HEAVY RAINSFLOOD KORAK Oct-84 271 hectors land were erroded.Three tourist hotel also flooded. HEAVY RAINSFLOOD KATHAR Aug-90 Flood destroyed 21 houses. HEAVY RAINSFLOOD RATNA NAGAR Aug-90 Ratnanagar were fully submaged in water for 3 days. HEAVY RAINS

FLOOD BHANDARA Aug-93Due to the flood in Rapti river Vandar, Katar,Kumroj,Padampur was water logged and the relief work was done by army, police. HEAVY RAIN

FLOOD GUNJA NAGAR Aug-93Flood in Narayani river destroyed 9 houses and 22 houses were damaged.Land was also erroded. HEAVY RAIN

FLOOD JAGATPUR Aug-97One permanent bridge worth Rs 5,00,000 was damaged and aroun 35 hectares of rice crops and vegetables. OTHER

FLOOD BAGHAUDA Aug-97 Heavy rain led flood on Reu river damaged houses. HEAVY RAINSFLOOD MEGHAULI Aug-97 Flood damaged 30 households. HEAVY RAINSFLOOD GARDI Aug-98 Flood damaged 4 houses.loss not mentioned. HEAVY RAINSFLOOD MEGHAULI Aug-98 Flood made ard-1,2 as island. HEAVY RAINS

FLOOD BHARATPUR N.P Jul-01 Closed the bharatapur airport caused by heavy rainfall. HEAVY RAINSFLOOD KHAIRAHANI Jun-71 A bridge over Khaireni was flooded. OTHERFLOOD PIPLE Sep-74 1001 m of highway was flooded and destroyed. HEAVY RAINSFLOOD KORAK Oct-84 272 hectors land were erroded.Three tourist hotel also flooded. HEAVY RAINSFLOOD KATHAR Aug-90 Flood destroyed 21 houses. HEAVY RAINSFLOOD RATNA NAGAR Aug-90 Ratnanagar were fully submaged in water for 3 days. HEAVY RAINS

FLOOD BHANDARA Aug-93Due to the flood in Rapti river Vandar, Katar,Kumroj,Padampur was water logged and the relief work was done by army, police. HEAVY RAIN

FLOOD GUNJA NAGAR Aug-93Flood in Narayani river destroyed 9 houses and 22 houses were damaged.Land was also erroded. HEAVY RAIN

FLOOD JAGATPUR Aug-97One permanent bridge worth Rs 5,00,000 was damaged and aroun 35 hectares of rice crops and vegetables. OTHER

FLOOD BAGHAUDA Aug-97 Heavy rain led flood on Reu river damaged houses. HEAVY RAINSFLOOD MEGHAULI Aug-97 Flood damaged 30 households. HEAVY RAINSFLOOD GARDI Aug-98 Flood damaged 4 houses.loss not mentioned. HEAVY RAINS

Past threats landslides/storms

5

Event village Comments Cause

LANDSLIDE Sep-74

45m of Highway was damaged and the transportation was blocked for some days. The landslide took place along the Mahendra Highway at BULBULE that lie in Between Hetauda and Chitawan. OTHER

LANDSLIDE Jul-81Transportation is closed since 4 days and still 3 days required to clear the path. OTHER

LANDSLIDE KAULE Sep-81 4 houses carried away by flood due to heavy rain & 3 people died. HEAVY RAINSLANDSLIDE Aug-90 2 Way transportation closed for 4-5 days.1 Police died. HEAVY RAINSLANDSLIDE KABILAS Jun-01 Black topped were damaged on some parts HEAVY RAINS

LANDSLIDE Sep-74

45m of Highway was damaged and the transportation was blocked for some days. The landslide took place along the Mahendra Highway at BULBULE that lie in Between Hetauda and Chitawan. OTHER

LANDSLIDE Jul-81Transportation is closed since 4 days and still 3 days required to clear the path. OTHER

LANDSLIDE KAULE Sep-81 5 houses carried away by flood due to heavy rain & 3 people died. HEAVY RAINSLANDSLIDE Aug-90 3 Way transportation closed for 4-5 days.1 Police died. HEAVY RAINS

STORM BHARATPUR N.P May-89

Thatched houses were damaged and many trees of jungle including the trees of mangoes and lichhi got down on the ground. Roofs of many houses were also carried away and electric pole was felt down and electricity was dead in Narayangirh OTHER

STORM BHARATPUR N.P May-89

Thatched houses were damaged and many trees of jungle including the trees of mangoes and lichhi got down on the ground. Roofs of many houses were also carried away and electric pole was felt down and electricity was dead in Narayangirh OTHER

STRONG WIND BHARATPUR N.P May-91 Electricity pole and telephone wire was damaged. OTHERSTRONG WIND May-95 Electricity pole and wire was damaged, telephone services was closhed. OTHERSTRONG WIND GUNJA NAGAR May-95 One house was damaged. OTHERSTRONG WIND DIVYA NAGAR May-95 Roof of schools building was destroyed. OTHERSTRONG WIND BHARATPUR N.P May-91 Electricity pole and telephone wire was damaged. OTHERSTRONG WIND May-95 Electricity pole and wire was damaged, telephone services was closhed. OTHERSTRONG WIND GUNJA NAGAR May-95 One house was damaged. OTHERSTRONG WIND DIVYA NAGAR May-95 Roof of schools building was destroyed. OTHER

Vulnerability of Chitwan in terms of Climate Change Induced Disaster

Source: DWIDP

Vulnerability of Chitwan in terms of Climate Change Induced

DARECHOK

CHANDI BHANJYANG

KABILAS

BACHHAULI Chitwan.shp

Chitwan2003.shp440000 - 967333967333 - 14946671494667 - 2022000

10 0 10 20 30 Kilometers

N

EW

S

Water-induced Disaster Map 2003 of Chitwan

Estimated Loss (Rs.)

NAPA evaluation of Chitwan CC Vulnerability

MoE, 2010, Climate Change Vulnerability Mapping for Nepal, National Adaptation Program of Action (NAPA) to Climate Change, GoN

Hydrogeologic Condition of Chitwan 1. Young mountains in the north, erosion prone rocks 2. Steep slopes dipping SW direction, from 1940 m to 200 m,

within 15 km; average slope of 12% 3. Heavy monsoon rainfall induced landslides and debris flow 4. Land Abuse: Anthropogenic loosening of soil (agricultural

intensification in sloped land, cash/high water demanding crops, over grazing, developmental activities without slope stabilization, deforestation)

• Debris (boulder) deposit in upper area • Debris (gravel) deposit in lower area (but no road to

transport gravel) • Debris (sand and clay mixed smaller gravel) deposit

immediately to the north of the East-West Highway

Chitwan District

Once upon a time, before the effect of CC was pronounced, the sand deposit in the river banks were resources of Chitwan District for construction industries

CC converted the resources (river bank sand) into problem in Chitwan District

• Due to CC, the extremes are becoming more frequent, resulting in increase in debris flow (upstream) and debris deposit (downstream)

• Debris deposit in the river bed is causing a) river bed aggradation, embankment breach and the

consequent flooding in the riparian communities b) River course diversion due to deposit in one bank of

the river, and consequent flooding in the another bank (next year or next flood), resulting in bank cutting, deposition of debris over agricultural fields…

c) Flooding in riparian settlements, ag. fields, protected areas

d) River enters villages; villagers settle in river course

Example of remaining debris deposit in 2003 in Lothar Khola (eastern boarder of Chitwan District) after 5 years: river bed aggradation, bridge opening reduced from 8 to 2 meters.

Too heavy sedimentation: Water quality

Summary of sediment production in the Lothar Khola watershed, 2003 Sub basins Catchm

ent (km2)

Total slided materials (m3)

Material outflow (m3)

Materials retained in hill slope

(m3)

Upper Lothar Khola Imti Khola Kali Khola Yurti Khola Bangsiling Khola Shankar Khola Rewati Khola Pangthali Khola Ganwarchok Khola Kuchur Tangi Damar

20.15 11.00 9.27 5.15

13.21 16.26 22.43 30.56 10.01

6.30 24.66

1521408 8000 8960

90200 60720

6600 1304000

17800 136800 204296 671280

1217126 6400 7168

72160 48575

5280 1043200

14240 109440 163437 537024

304282 1600 1792

18040 12144

1320 260800

3560 27360 40859

134258

Total 169.00 4030064 3224051 806013

Summary of sediment production in the Lothar Khola watershed, 2003

Previous similar extreme event occurred in 1993. Source: Ulak, P.D. , 2008 Materials waiting to come down.

Lothar Bridge between Chitwan and Makwanpur

Problems due to CC induced debris deposit in Chitwan, Lothar Khola

1993: debris flow & deposit in RB, RB village inundation 1994: embankment in RB 2003: more debris deposit RB, river migrate to LB 2007: further shift to LB, forest destroyed 2010: LB village inundation 2011: embankment in LB, ban on SGS extraction in LB

Problems due to CC induced debris deposit in Chitwan

Sand deposit diverts river course and necessitates channel excavation every year in East Rapti-Lothar Irrigation in Chitwan District

Current adaptation measures (convert problem into resource)

Upstream: Reduce landslide and debris flow – Slope stabilization, forestation, bioengineering (DSCWM),

community forest – sabo dams, check dams, gabion walls, other soft measures

(DWIDP), – retaining walls, surface/side drains in the immediate

vicinity of highway (DoR) Downstream: clear the debris deposit and side protection • Embankment (People’s embankment project), river

training, gabion walls (DWIDP), • Effectiveness of line agency’s mitigation measures yet

to be clear Short term adaptation: • gabion wall and sand mining (DDC), as per LSGA

Debris Source area Deposit of bounders/gravels but no road access

1890 m

175 m

1940 m

200 m

Annual sediment yield: 73.6 Million ton

Chitwan District

Scale of fluvial sedimentation too big: 26886 trucks per day, 3 m3/truck, 365 days/year

List of DDC registered sand mines (anticlockwise in previous slide)

1. Darechok Khola /Trishuli River in Darechok VDC 2. Jugedi Khola in Kabilash VDC 3. Khageri Khola(boarder of Bharatpur Municipality and Jutpani VDC) 4. Thanbung Khola in Jutpani VDC 5. Kayer Khola (boarder of Pithuwa and Chainpur VDC) 6. Ladara Khola in Chainpur VDC 7. Pampa Khola in Birendranagar VDC 8. Chyatra Khola in Bhandara VDC 9. Dudhkoshi Khola in Bhandara VDC 10. Martal Khola (boarder of Bhandara and Piple VDC)

Note: Data depends on source! Mines not registered at DDC are not

listed. Sand mines located entirely within forest area are not listed.

DDC Sand Mining Management Process • DDC identifies sand source every year (in areas that are not within forest)

(source area and amount depends on existing and last year’s debris deposit) • DDC calls for IEE study through consultancy services • IEE report to specify amount, location, environmental safeguards,

monitoring • DDC calls for bidders for each mine site • Agreement with highest bidder, including mode of payment (block or

installment) • Contractor pays the DDC or DDC+ Forest (depending on the location of

mine area). It is a source of conflict between DDC and Forest Office. • DDC to monitor mine operation for the duration of contract. • MoFALD is monitoring through its own technicians and university

students. Local residents are also monitoring. • If river bank eroded, provide fund for gabion walls and other river

training activities. National average is about 19% of revenue generation.

Pampa Khola SGS Mining, Chitwan Pampa Khola gravel Mining

Pampa Khola annual flood level

Martal Khola between Bhandara and Piple VDC

Some facts and figures about sand mining in Chitwan District

Nepali Fiscal Year

SGS Revenue (NRs.)

Total Revenue (NRs.)

2066/2067 (2009/10)

1923212 9152674

2067/2068 (2010/11)

1514328 16258125

2068/2069 (2011/12)

5907918 16675723

IEE provision applied in Chitwan since March 2011 (2067-11-19 BS)

Positive impact of sand mining (national)

Environmental • Maintenance of river bed elevation • Reduced flooding in riparian settlements, ag. lands, conservation

area Socio-Economic • Increase in internal revenue (2008/9 estimate is NRs. 1072 million,

National) ; can be increased at least 3 fold by better management • Employment generation for unskilled and poor • Enhanced economic activities • High FIRR and higher EIRR • Saving of river bed elevation maintenance fund • Forex (mainly IC) • DDC Fund for developmental activities, including river bank

protection

Kayer Khola SGS Mining, Chitwan

Kayer Khola Scraping of river bed, notice the river bottom clay

Unmanaged and unmonitored sand mining: convert the resource into problem

Problems due to unmanaged SGS mining in Chitwan, Ladari Khola

Negative impact of sand mining (from resource to problem)

• River bed degradation • River course change • River bank erosion • Landslide • Forest clearance • Infrastructure damage • Environmental degradation • Fund required for rehabilitation • “Mafia” intervention All management related. The sand mining impacts are similar in Chitwan District, to a lesser

degree.

Converting the problem back into resource: 1. Better and practical guidelines for sand mine operation 2. Updating of existing IEE/EIA to address potential impacts of CC 3. Input to the process of development of Environmental Friendly Local Governance (EFLG) at MoFALD 4. Update provisions of NAPA/LAPA regarding sand mining (Nat’l Adaptation Program of Action, Local Adaptation Program of Action)

Ministry of Science, Technology and Environment

Govt. of Nepal Mainstreaming Climate Change Risk

Management in Development

What it has to do with regionalism?

• Major portion of the sand goes from Nepal to India for development activities of north Indian states in Ganges Basin

• “Highways” made in India from sand, gravel and stones imported from Nepal obstruct the river flow and inundate parts of India and Nepal

• Most of the sand mines in Nepal are in districts which are close to India. Unmanaged sand mining can be a headache for both Nepal and India, especially if the river course changes