Engr Iftikhar Ahmad

Area to be submerged
There have been varying figures of the actual area to be submerged under the reservoir. WAPDA has been indicating the minimum possible figures, assuming provisional facility for one season cropping, and leaving the title with the landholders.
Whereas the calculation of the total area, expected to be submerged under the KBD waters is beyond the scope of this research, however, the point worth emphasising is that the land to be affected by the KBD reservoir will not only be the one that gets submerged under the water, but will also be the one that gets inundated every five years (by 1 in 5 year flood).
In fact, it is not only the land area that will be snatched by the waters of KBD, but is the total area declared dangerous for safe development due to the increase in its risk factor for productive investment. And since flood plains are never regarded as safe boundaries for development, hence the actual land area to be affected by the KBD would be many times more than what is being claimed by KBD under its waters, as projected by WAPDA in its reports.
Moreover, and as a matter of great concern, the thousands of acres of rich cultivable land in Mardan, Charsadda and Nowshera Districts is feared to turn into swampy marshlands in the long run. Since the area has been fully developed with tremendous cost, its submergence will be a major loss to NWFP (Pakhtunkhwa) in particular and Pakistan in general.
At the same time, the creation of a 164 sq. miles of water pond in the middle of a fully inhibited area will be a major and perpetual hazard for accidents to happen.
Long-term impacts of Kalabagh dam project
Like its short-term impacts, KBD is going to have a long standing extremely injurious impact on the lives of the people both living in the immediate vicinity of project, as well as in the rest of the country.
The details of these impacts would vary in nature and in magnitude, and will appear in different moments of coming times to have devastating effects on the civilisation of this whole region. Some of the most important long-term impacts of the KBD are discussed below:
Increase in surface water salinity
Water of the Indus River system carry a variety of salts that are left on the surface of irrigated land, while the irrigation water filters down or evaporates. To comprehend this, we need to understand the relation of irrigation water suitability to that of its salt contents.
Soil scientists believe that, when the contents of salt deposits increase to about 2.5% the productivity of the land is visibly impaired and when it reaches a level of 7.0% no biological life is then possible in the soils.
The following table describes the categorisation of the quality of water with the varying degree of salt content in the soils.
Some authors propose slightly lower permissible limits for chlorides than for sulphates, due to their more injurious characteristics.
To study the potential of Indus water to induce salinity, the following table from Dr Nazir Ahmad's research describes the salinity ratings at various points in Indus River:
>From the above table, it can be observed that the quantum of salinity between Attock and Kalabagh (52 gms/ton) is 100% more than between any other of the two points observed in the analysis.
To visualise the effect of the use of saline water in irrigation systems, Saeed A Rashid, in his excellent treatise "KBD; A Scientific Analysis", has stated the problem in the following words: "If 10 inches of water carrying 200 PPM of dissolved salts leave behind 4.72 gms of solids per cubic foot and if 10 inches of such water is given to a piece of land and is allowed to soak and evaporate in the same pattern as is practised in our canal irrigated agriculture, then 4.72 gms of slat will be deposited in each cubic foot of soil.
Given the salinity of water of River Indus at DI Khan of 226 PPM for every 3 soaking per year, or 30 inches of water, about 16 gms of salt will be added to each cubic foot. And in 30 years time, about 2.54% salts will be added to the top 8 inches of soil making damage to crop field perceptible".
Saeed A. Rashid advances the interesting theory that, "perhaps that is the reason why the crop yield has started declining in the command areas of the canal system below DI Khan, 30 years after the commissioning of the barrage system when maximum coverage is achieved".
To study the effect of saline water's use in the backdrop of KBD, it is revealed that, the billions of tons of the stored water in KBD is likely to exert tremendous pressure on alkali brine strata, which will then rise in vast sheets to mix with water of the reservoir and further increasing its saline content to unacceptable limits.
This water when used for irrigation purposes, will play havoc with any soil that comes in contact with it through irrigation, or otherwise.
These observations indicate a very grave threat of destructive salinity to all agricultural lands below KBD site, if a dam were to be built at the proposed site, and its waters used for irrigation purposes. This needs to be further viewed into the purview of the already saline 24 million acres of irrigated land, out of our total of 34.5 million acres of irrigated land of Pakistan.
Flooding in Nowshera valley
It has been repeatedly stated that the water for KBD will cause severe flooding in Nowshera valley, and has been constantly refuted by WAPDA through various tactics.
The flooding history of Nowshera describes the flood of 28th and 29th August, 1929 as having reached a maximum of 951-ft level above the mean sea level. The hydrologists have worked out the average return period of such a flood as 1 in 100 years.
A relatively lesser intensity of flood was experienced in 1978, which touched the heights of 945-ft above mean sea level. (Ref: Dr Kennedy Report)
It is feared that, if the water level rises to the 1929 heights, or even the 1978 levels, it would be fairly high above the normal reservoir retention levels, thereby causing major destruction in the towns on the River Kabul banks, and over topping the Kalabagh dam itself.
To further aggravate the problem, the increased sedimentation overtime, may raise this height in River Kabul much further, and bring large-scale destruction in the surroundings.
To technically address the issue, the following monthly average flows of River Indus needs analysis:
Form the above table, it becomes evident that more than 65% of the annual water flow of Indus takes place between the months of June to September each year, when the snow melts in Himalayas and Karakoram Range and combines with the monsoon season flows. And the remaining 35% flow is spread over the 8 months period from October to May.
Saeed A. Rashid, in his book "KBD"; A Scientific Analysis", has analysed the problem. He reveals that "Assuming a normal distribution, 68 percent of the times, high floods could bring an inflow of 27 MAF in July, showing the most possible probability of larger flows coming into the Indus River system. Only 4.6 percent of the times a flood could bring an inflow of 34.02 MAF, and there is 0.01 percent chance of a flood bringing in 46.06 MAF in the month of July.
As per the design parameters, the retention level of water at KBD is just sufficient to contain the September inflow and the peaks are planned to be passed on, as it is.
Even if there is a capacity to contain a flood of 34 MAF, it will only flood the country upstream, instead of flooding downstream. Whereas the downstream river regime is better adjusted to handle large volumes. And there would be large-scale devastation in upstream habitat areas".
In the original design, WAPDA had provided for the construction of protective dykes around the major cities of Kabul River, so as to protect the water from over-spilling the banks of the river and destroying life and property. Which upon the objections from NWFP (Pakhtunkhwa), had been eliminated with the reduction of 10-ft reservoir level, claiming to solve all the flooding problems.
Intriguingly, the revised designs show the dam height as the same El.940-ft above MSL, leaving a ridiculous 25-ft freeboard over the normal reservoir level, as against 5 to 7 ft common practice.
This raises the questions:
i. Why was the flooding danger ignored in the first instance?
ii. How will the 10-ft reduction in reservoir level altogether avoid the 25-ft dykes at Nowshera?
iii. Why has the dam level been maintained at the same 940-ft elevation, leaving the ridiculous looking 25-ft freeboard over the normal retention level?
iv. Why has WAPDA been overshadowing the sedimentation effect in Kabul River, feared to raise the bed level and exacerbated the flooding problems.
v. Why has WAPDA been pleading the utility of Munda Dam in reducing the flooding problem at KBD, when the Munda Dam has only 0.37 MAF of flood storage, and can play only an insignificant role in reducing the extreme seriousness of floods at KBD?
(Ref PC-II for Feasibility Study of Munda Dam Project, March 1997, WAPDA)
vi. Why has real model analysis of sedimentation behaviour been avoided, so as to technically address the issue?
Indus Water Salinity
Observation Point Salinity gms/tonne Difference
Ghaziabad 138 __
Attock 164 26
Kalabagh 216 52
D.I. Khan 226 10
D.G. Khan 242 16
Chechran 260 18
 

Water Total Sodium Concentration
Classification Dissolved Salts  MEQ/L

 ECx10-5 25oC PPM % Chlorides Sulfates
Excellent 25 175 20 4 4
(less than)
Good 25-75 175-525 20-40 4-7 4-7
Permissible 75-200 525-1400 40-60 7-12 7-12
Doubtful 200-300 1400-2100 60-80 12-20 12-20
Unsuitable 300 2100 80 20 20
(more than)
 
 

Inflow at Indus (MAF)

Month Low High Av
April 2.49 5.59 4.00
May 5.74 9.00 7.99
June 14.68 19.00 15.46
July 15.01 24.94 21.96
August 18.23 23.39 20.96
September 6.24 17.92 9.58
October 2.30 7.01 3.51
November 1.47 3.65 2.15
December 1.20 2.42 1.86
January 1.25 1.99 1.77
February 1.20 1.82 1.65
March 1.94 3.37 2.36
Reference: Dr. Nazir Ahmad, Water Resources of Pakistan and their Utilization
Continued