A satellite image of Srinagar, as viewed on Google Crisis Maps. September 2014. The flood channel dug in 1904 exits from a bend in the Jhelum and goes to the left of the picture.

 

The Vale of Kashmir is an  intermontane valley, flanked by the main range of the Himalayas on the northeast and the Pir Panjal Range on the southwest.  It is an ancient lake basin about 85 miles (140 km) long,  20 miles (32 km) wide, and 5,300 feet (1,620 metres) high that is drained by the upper Jhelum River.  The population of the Kashmir region is concentrated in the valley, at the centre of which lies Srinagar, the summer capital.  The fertile alluvial soil yields rice, corn, saffron, fruit, and vegetables, and the scenic mountains and lakes (notably Wular, Dal, and Nagin) attract many tourists.

The Dal Lake at Srinagar

 

The river Jhelum originates at Verinag at the southeastern edge of the Valley.  It flows northwest through Srinagar into the shallow Wular lake.  The  Wular  lake’s size varies seasonally from 12 to 100 square miles (30 to 260 square kilometers).  The Jhelum exits Wular lake at Sopore, flows through Baramulla and starts its descent a few kilometres later at  Khadanyar.

The Wular Lake

 

Those not familiar with the Valley should note that Srinagar sits in an alluvial plain more akin to Kolkata than a hill town.  There is a drop in river level of only 35 metres from Srinagar to Baramulla – a distance of 55 km by road and much greater by river.  In fact, the river meanders between Srinagar and Baramulla.  It is well known as a flood prone area.  In recent history, there was a major flood in 1902  when portions of Srinagar city remained submerged for two years.  The Maharaja sought help from the then British government, who dispatched a team of engineers. The British team dredged the  Jhelum from the mouth of  Wular  upto Khadanyar,  a few km downstream of Baramula.  A 42 km long flood channel was also constructed from Padshahi Bagh (Srinagar) to Wular.  This flood channel is designed to carry  1/3  the expected flood  flow of 1,50,000 cusecs.

Baramulla in winter

 

 

Baramulla Rail Station

 

In 1948  Sheikh Abdullah requested Prime Minister Nehru for a dredger.  Nehru acceded to the request and commissioned the dredger himself.  It was used for  regularly desilting the flood channels and the river itself.  When a major flood occurred in 1959, some areas of the city  were submerged, but there was no loss of life or property.

In 1976 government constituted the Uppal committee who recommended various measures for flood control.  However,  no action seems to have been taken.  Instead silt has accumulated in all the major tributaries and the flood channel. In fact,  the then  minister for flood control and irrigation, Taj Mohi-ud-Din, is on record  that even the Srinagar Development Authority has constructed a shopping complex on the flood channel.
[See http://www.greaterkashmir.com/news/2010/Feb/12/srinagar-awaits-catastrophe-57.asp  dt 11 Feb 2010 ]

Before

Railway Station
On the outskirts of Srinagar, the floods have inundated almost everything at the Nowgam Railway Station, except the railway tracks and the main terminal

 

After

Bakshi Stadum Before

Bakshi Stadium
The state’s first synthetic football pitch was laid at the Bakshi stadium just days before it almost completely went under water.

 

Bakshi Stadum After

 

Before

 

Triangular Park, Jawahar Nagar
Roads and parks in Srinagar were completely submerged, leaving only rooftops and a smattering of treetops visible from above.

 

 

After

After the excellent work done by the British team in 1902 – 04 and the state government team in the 1950s, the people and the government became complacent and negligent.  Reliance was placed entirely on the embankments (bunds) that have been built on either side of the Jhelum.  Bunds can supplement dredging but are never a complete solution by themselves.  Over time, the river silts up and the level rises.  To counter this, the bunds have to be raised further.  This process continues till we get the weird spectacle of the river bed being higher than the city.

Bunds have another problem.  What do we do about the tributary streams that join the river ?  When the main river level rises, water will flow backwards in these tributaries.  That would flood the city. So the bunds have to block the tributaries.  And then, flood channels have to be dug to divert the tributaries till they join the main river many kilometres downstream.

It all  adds up to a complicated, expensive and inefficient system.  And dangerous to boot.  Whenever the bund is breached, or if the river level rises above the bund,  severe floods result.  The entire river empties into the city.  And that is exactly what  happened  on 07 September 2014.

An aerial view showing buildings partially submerged in Srinagar. Photo: PTI.
The entire Jhelum valley, including portions in Pakistan, got flooded

 

Far simpler, better and  less expensive to dredge and de-silt the river.  Then, if at all the river floods, only a small fraction of the water will overflow the banks.  As in 1959, the impact will be minor and limited to the flood plain.

After the initial capital dredging, maintenance dredging has to continue

A dredger in operation

 

The basics of fluid flow, as applicable to a river,  are given in the Annex.  The important point is that the cross sectional area available to the river must be large enough to cater to the volumetric flow during floods.  The volumetric flow is equal to A x V, where A is the cross sectional area and V is the velocity of the water.  The velocity is determined by the slope of the land and is beyond our control.  Dredging and de-silting — and, therefore, cross sectional area — is within our control.

All rivers have a normal wet season level.  This determines the width of the river channel.  However, every now and then, the river will flood.  The area which floods occasionally is called the flood plain.

In ancient times, when the pressure on land was low, people avoided building houses in the flood plain. It was used for agriculture.  But, as the population increased, urbanisation set in and the flood plains became filled with buildings.  People also built  bunds to “keep out floods.”  The problem is that, if and when the bunds are breached, the floods become more severe.

Almost the entire city of Srinagar sits in the flood plain of the Jhelum river.  Any breach of the bunds in Srinagar inevitably causes the whole city to become a lake.

 

WHAT   NEXT  ?

 

 

 

After the initial rescue phase, thought will have to be given to how best to repair the damage and rebuild the city.

Breaches to the bunds need to be repaired.  But, instead of raising the bunds further, it is better to dredge and de-silt the river and the flood channel.

A dredger operating from a barge

 

While the principle is simple  — increase the cross sectional area available to the river — we do have  a major problem in the Valley.  The river drops only about 35 metres while flowing a distance of about 75 km from Srinagar to Khadanyar, near Baramulla.  So local dredging at Srinagar is not enough.  We need a massive dredging programme all the way unto Khadanyar.

The flood channel built in 1904  is equally important.  It requires deepening and widening.
In view of the urgency and the mammoth task involved,  multiple dredgers and multiple contractors should be involved.  Floodlights should be arranged and dredging should be done round the clock  —  24 / 7 / 365.

The alternative — Plan B  — is to leave Srinagar as a lake and build a new city on higher ground.

 

A picture of the flood affected area.

*

A policeman stands guard outside the Hajj House in Srinagar in the middle of the worst ever floods to hit the region.  Since the city is lower than the river,  the water will not drain back to the river even when the flood recedes.

 

 

 

Kashmiri residents are evacuated from a flooded neighborhood on a tractor in Srinagar (Photo: AP)

 

 

Ghanta Ghar, in the heart of Srinagar, surrounded by flood water on Sunday (Press Trust of India photo)

 

 

 

Annex to
Flood Prevention in the Valley

 

 

BASICS  OF  WATER  FLOW

The basic law of fluid flow is the Law of Continuity which is nothing more than a corollary of the Law of Conservation of Mass.

In any pipe or fluid stream, provided there is no nuclear reaction, the mass of fluid that exits the pipe or fluid stream is equal to the mass that entered it.  If the cross sectional area is A and the velocity is V, the volumetric flow is A x V.   Multiply by the density, Rho, and we get the mass flow (MF).  So the Law of Continuity says that MF (in) = MF (out).

For  flooding of a river, think of flow from right to left in the above diagram

 

For the case of water flow in a river, the density changes are negligible.  So we have the fundamental equation  A x V = Constant.

Now, the velocity of  water in a river really depends on the slope of the river bed.  In the hills,  the slope is steep and it causes fast flow and a narrow cross section.  As the river enters the plains, the slope is less and the velocity reduces.  By the Law of Continuity, the cross section of the river has to increase to compensate for the slower velocity.

The total quantity of fluid that goes past a point in unit time is called the “flow.”  The volumetric flow is  A x V and the mass flow is  Rho x A x V.  As discussed earlier, the density of water at different points in a river can be considered to be constant.  Hence, water flow is customarily stated in volumetric terms.  The most popular unit is “cusecs” or cubic feet per second.

Flow in a river is estimated by measuring the velocity at different points in a given cross section.  By mapping the velocities in a cross sectional diagram, an estimate is made of the flow.  Historical data maintained over several decades then gives the average and flood flows.  A margin of safety is then added and flood control measures designed accordingly.