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Of Floods and its Fury

“Floods were never seen as disaster, they were a blessing

to the village, until recently”, Chandrasekhar ji, as he

is reverently known as, remarked. So did many other

villagers in Supaul district in North Bihar that lies in the

Kosi basin, and is regularly affected by floods.

In North Bihar, floods were dealt with by the local people

as ‘a way of life’. “In fact, floods were like daughters

visiting their father’s place; she is welcomed with open

arms, but must go back to her abode”, chuckled Neelam,

a middle-aged lady residing in the region and working

with villagers for disaster preparedness and other

associated issues.

However, in the recent years, the intensity and frequency

of floods have increased significantly. The Himalayan

river has one of the highest annual sedimentation load in

the world, making it highly prone to flooding. And climate

change-induced glacial melting leads to dangerously high

water levels in the Kosi basin and potentially more silt,

leading to catastrophic floods and related disasters.

The Hungry River: Looking through Floods and Silt

on ImpactMARCH 2018

Department for International Development, UK has assisted the Government of Bihar in developing a roadmap to estimate the amount of silt deposited in the Kosi basin, and assess productive uses and economic benefits of silt to prevent floods in the state.

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As a result, most of the villages have to relocate to

the other side of the embankment during monsoons.

Whenever the water level starts increasing, they have to

displace themselves, their livestock, crops – everything.

It is an endless sequence of events where houses are

built and destroyed and rebuilt. And among many other

anthropogenic reasons, including several interventions

for water resource development, excessive siltation

forms a central part of this problem.

“Kosi has been changing its course whimsically. We have

seen it change its course twice in the last ten years. The

land that you are walking on was a deep flowing river

a few years ago. All we can see now is the bed of silt

everywhere, where usually we used to find fertile soil”,

said Baldev Jadhav, an old villager. Often more, Kosi has

been referred to as the ‘sorrow of Bihar’, meandering

and depositing fertile fields with abrupt heaps of silt and

tearing away big chunks of land. During monsoons, the

huge amount of water coming from the vast catchment

area of Kosi makes it difficult to move through silt, thus

resulting in overflowing. And in summers, it is spread

across in patches of silt and water.

The Silted Land

“The amount of silt deposited in Kosi has only increased

over the years”, says Ram Chandra Paswan, a primary

school teacher in Naraiya Village. He claims that there

is a minimum increase of 5-6 inch of silt every year.

River embankments are expansive and the dilapidated

school building can be seen standing in the midst of the

accumulated silt.

Simultaneously, on the other side of the embankment,

new low-lying land, known as chaur, is continuously

formed due to deposition of silt, which remains

waterlogged throughout the year. And thousands of

acres of existing arable land have become water logged,

causing tremendous loss to crops and cultivation.

Livestock rearing has also been impacted as excessive

water logging leads to limited grazing land.

A Suitable Crop

Silt has also led to shifting of many traditional crops as it

lends no water retention capacity in the crops. Hence, a

lot of crops that were traditionally cultivated in the region

have had to be replaced. Hira Devi, a farmer who has

seen the change in her crop cultivation, exasperatedly

recounts her experience, “I have been living in this village

for about 25 years. Farming has only been getting difficult

day-by-day. We are resettling here and there, the land

keeps varying year after year. You sow a crop on this land

today, and tomorrow you see dunes of silt everywhere.

The sheer amount of silt and uneven land due to shifting

of deposition of silt makes farming, which is the only

occupation we have, very difficult. We are always

uncertain of what tomorrow holds for us”. And uneven

land makes it laborious to walk and commute from one

village to the other. Irrigation of crops is another major

issue as the area is battered by either too little or too

much water.

The story in the Ganga basin is the same, with similar

repercussions in its traditional lentil cultivation, a major

crop in Mokama Taal vanishing along Ganges from the

areas closer to the river, due to massive quantities of silt

deposition. These have been replaced with wheat, the

economics of which is relatively not profitable.

Solutions lay within

Getting rid of this silt is one plausible way to start

solving this problem. But how does one begin with it?

Piprahari Village in Supaul block has mend their ways with

increasing silt. They have found a way to purify drinking

water by using silt to make pots for drinking water.

Excessive silt is also being used to build roads, landfills

and deeply excavated fields for brick making, and

roadside excavated fields, etc. Most commonly, this silt

is being used by villagers to raise their houses and brace

themselves against floods. “The villagers have to find

a way to adapt to these volumes of silt. If government

supports the poor farmers in dumping silt in their

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respective agricultural low-lying land, it will be very

helpful for them. Though it may not yield immediate

results, it will become an upland, and the farmers can then

use manure to make it suitable for crop cultivation. The

lands would be better than the waterlogged lands where

nothing is possible.” says Chandrashekhar ji assuredly.

The communities are also looking at ways of adapting

to cultivation of crops that can be grown on silt instead.

Even though Kosi silt is slightly deficient in nutrient

value, some villagers suggest that alternate crops such

as watermelon can be considered by supplementing it

with compost for improving the fertility. However, this

still requires behavioural shifts in agricultural patterns

of farmers to move from traditional crops to newer and

innovative ways of sand farming.

Creating a macro-change

While there is cognizance of potential solutions, the

Government of Bihar has been eager to explore and

scale-up the beneficial usage of silt. In collaboration

with various research institutions, it had been working

on pilots of products with silt and establishing usage of

silt. The Action on Climate Today (ACT) initiative joined

hands with the state government on this and is working

on innovative methods to manage silt from the Kosi river.

Estimating the amount of deposited silt and managing

it for commercial purposes was found to be among the

top-most adaptation strategies to address the problem

of recurrent floods caused due to over deposition of silt.

Pankaj Kumar, Team Leader, Bihar, ACT-CCIP, “The state

government and ACT have found resonating needs to

bring about a robust sediment management plan and

share a similar vision of bringing change on the ground.

A two-pronged approach has been adopted, one that

5 km

Sediment Management in

‘River Kosi’ Bihar is an Indian state, which has been ravaged by floods every year and affecting the large and highly vulnerable rural poor. The River “Kosi” is known as “sorrow of Bihar” because of the floods it causes and the widespread suffering through devastating floods. This Himalayan river carries very high annual sedimentation load, which has led to multilayer staking of silt. In addition, climate change and increasing rate of glacial melt upstream, may lead to greater flooding and sediment deposition in Bihar. Removing deposited silt and managing it for commercial purposes was found to be one of the adaptation strategies to address the problem of recurrent floods caused due to over deposition of silt. Government of Bihar in collaboration with various research institutions had taken up pilots on products with silt and establish usage of silt.

Birpur

Baltara

Very low

Low

Moderate

High

Very High

Legend

EXTRACTABLE SILT

HighAggradation

zone

202 6 3(10 m )

EXTRACTABLE SILT

Very HighAggradation

Zone

311 6 3(10 m )

+ =

TOTALEXTRACTABLE

SILT

513 6 3(10 m )

Hotspots of

Siltation

Likely Benets andRecommended

Governance Actions

Road ConstructionLandfilling & Agriculture

50,000hawaterlogged land in Saupaul

90%extractable

silt

Kharif & RabiCultivation

50,000ha

IncreasedAgriculture Productivity

and HH Income

Application of Dredged siltin low-lying and flood-prone

district of Supaul

Building LocalEntrepreneurship

A package to reclaim the lands may include landfilling by silt and this may be integrated with supplementing improved seeds and organic manures to augment agriculture.

Radiusof the river

Large volumes of silt can be used for road construction activities including widening or raising the height.

Wi l l produce mul t ip l ier effects of flood protection and saving of precious soil

N e e d s a m a j o r p o l i c y intervention to make the use of silt compulsory within100 kms of the river

Dredged silt can be applied in low-lying fields and organic manures and fertilizers

can be added to improve productivity.

Opportunity of

EmploymentGeneration

Conducive policy and promotional schemes can be planned for setting up small scale industries on paving block, wall tiles etc.

In addition, existing s c h e m e s l i k e MGNREGA can also be linked to the Silt Management Process.

Supaul

This is the graphical representation of ‘River Kosi’ just to explain the silt deposit. This should not be treated as the actual geographical map.

Birpur

Barrage

within

15 km

s

Road Construction

Saharsa

covers the technical aspect and the other that looks at

commercial viability of silt. The technical part aims to

estimate the deposited and extractable silt in various

stretches of the river. The commercial aspect looks at a

commercial plan for usage of the dredged/removed silt.”

This study under this joint initiative suggests that

the excess silt has proven utility in reclaiming lowland

and waterlogged areas, which can help protect the

villages from recurring floods. It can also be used in

low-lying agricultural fields, in road construction, brick

manufacturing, new landfills and perennial horticultural /

medicinal crop cultivation, thereby leading to increased

production and household income. The study also

recommends integration of MGNREGA schemes with the

silt management process.

ACT is looking at providing policy recommendations

on how to manage the de-siltation process, and also

proposes a comprehensive framework that can be

applicable not just to Kosi but for other rivers of the state.

ACT and the Government of Bihar will bring together key

stakeholders on a platform to initiate and structure a new

way of discussion on silt management in Bihar that will

build a shared understanding of silt management in Kosi

and the dual opportunity it presents in building resilience

as well as economic development.

Friends of the River, and of the Sand

Sediment management in the Kosi Belt is a complex

issue. And it needs a holistic approach that involves

all stakeholders, and critically the local community.

They need to be encouraged to use the dredged silt for

agricultural and other livelihood purposes. Policymakers,

researchers and civil society can capitalise on the

awareness of the local community in developing robust

methodologies and plans on desiltation.

“Yes, we have to cope. And that is why we are looking for

solutions from within”, speaks Halima, an elderly farmer,

as she retires from her day-long work in the field. “We do

not want another 2008 flood like event to happen ever

again. And that is why we believe we must be friends with

both the river and the sand!”

Silt: From Impediment to Solution

Excessive siltation in the Kosi basin is a massive problem

that the region is grappling with, and is an impediment

to the state’s growth and development. Through ACT’s

interventions, the state now has an estimate of the

amount of silt deposited and will be better positioned

to develop a sediment management framwork. Most

importantly, the commercial benefits proposed can help

transform this story of disaster to one of opportunity.

ACT (Action on Climate Today) is an initiative funded with UK aid from the UK government and managed by Oxford Policy Management. ACT brings together two UK Depart-ment for International Development programmes: the Climate Proofing Growth and Development (CPGD) programme and the Climate Change Innova tion Programme (CCIP). The views expressed in this leaflet do not necessarily reflect the UK government’s official policies.

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Problem Identification

Measurements

Silt Management

Benefit /cost (B/S) analysis

Recommendations and Action Plans

Process understanding of Sediment dynamics

Causes and problems as-sociated with Siltation

Estimation sedi-ment load

Sediment Rating Curve

Reduce sediment production

Removal of deposited sediment

Route sediment (maintain transport,

minimize deposition)

Artificial Neural Network models

Empirical Equation

Benefits

1. Agricultural

2. Filing Material

3. Fishes

4. Subgrads material

Costs

1. Cost of reduction

2. Routing

3. Removal

4. Ecological loss

1. Sediment Bypass

2. Sediment pass

through

3. Density Currents

1. Catchment Area

Treatment

2. Bank protection

3. Check dams

4. Contour Bounding

1. Dredging

2. Mechanical

excava-

tion

3. Flushing

Management Practices

Hotspots identification Sediment connectivity

Natural

Anthropogenic