Managing Disasters

The country is confronted with unusual circumstances in which drought and flood phenomena coexist

Rapidly changing weather patterns, where long periods of drought frequently coincide with devastating floods, are a visible sign of climate change’s impact on Pakistan, as the South Asian country of over 200 million people faces one challenge after another throughout the year.

In June, Pakistan was faced with an acute shortage of water as its main water reservoirs reached their dead levels. While the minimum safe limit for water storage capacity is 120 days, Pakistan only had 30 days. In comparison, many developed countries have water storage capacity of up to two years. Low water storage capacity has had the greatest impact on agricultural productivity in Pakistan, causing it to contribute 21.8 percent less to its GDP.

Similarly, the once 5,000 cubic metres per person water availability in 1951 has already fallen below the minimum required 1,000 cubic metres per annum per capita, classifying the country as “water stressed,” but more alarmingly, moving towards becoming a “water scarce” country, with projections indicating that in 2025, the estimated 250 million population will have around 700 cubic metres of water available for each person.

Likewise, repeated floods have caused devastation along the entire path of Khyber Pakhtunkhwa’s two main rivers, the Indus and the Swat River. The Tarbela Dam on the Indus River provides reliable protection, while the Warsak Dam on the Kabul River outside Peshawar protects it from flooding. The Swat River’s lack of a similar water storage capacity has frequently endangered lives, crops, and properties in Upper Swat, Malakand, and the Peshawar valley, which includes the cities of Peshawar, Charsadda, and Nowshera.

Dams of all sizes—small, medium, and large—are critical components of comprehensive and integrated water management systems. Dams divert water, store it for long periods of time for effective use, and help to mitigate floods and alleviate the impacts of droughts. Dams also relieve drainage congestion and ensure the timely and continuous supply of irrigation water required to meet crop and livestock demands.

Mohmand Dam, formally known as Munda Dam, was conceived in 1963 when the Water and Power Development Authority (WAPDA) began a geological investigation at the dam site to forecast future electricity demand in the country. WAPDA completed a pre-feasibility study in 1992, and the Japan International Cooperation Agency (JICA) completed a feasibility report on the dam project in 2000.

However, the historic super flood of 2010 highlighted the importance of Mohmand Dam. The Flood Enquiry Commission, established by the Supreme Court of Pakistan in December 2010, recommended the construction of the Mohmand Dam Project to control floods in the districts of Charsadda, Peshawar, and Nowshera. Similarly, the Diamer-Bhasha dam on the Indus River was proposed to serve the same purposes.

According to water expert Dr. Shakil Hayat, PhD in water governance from the University of Amsterdam and the UNESCO-IHE Institute for Water Education in the Netherlands, the main goal of the Mohmand Dam is to prevent floods on the Swat River.

“The Tarbela Dam on the Indus River is clogged with silt and sediment, which is why the Diamer-Bhasha dam was proposed to prevent floods, generate electricity, and store water for various uses. Similarly, Mohmand Dam is critical for mitigating floods on the Swat River. It will also generate electricity and store water for various uses,” Dr. Shakil maintained.

“In Pakistan, the drought and flood phenomena coexist. Long dry summers cause dams to fail, and unprecedented monsoon rains cause floods in July and August. As a result, any dam proposed in Pakistan must account for both drought and floods. Dams should be able to store access water during flood seasons as well as store enough water during droughts,” Dr. Shakil stated.

Dr. Shakil went on to say that dams can effectively minimise flood damage. “If the Mohmand and Diamer dams had been built in time, the 2010 floods would have caused minimal damage,” the water expert argued.

“The most pressing issue for dam construction is the availability of funds, which our governments do not have. However, as a climate-vulnerable country, Pakistan has access to nearly $100 billion through the Green Climate Fund (GCF) portfolio. It is up to the relevant departments to link the construction of new dams with climate change adaptation, because new dams will fight floods while also providing water for drinking and irrigation during droughts,” Dr. Shakil asserted.

The Mohmand Dam, located 47 kilometres north of Peshawar in the Mohmand Tribal District, is a multipurpose dam project with a gross storage capacity of 1.239 MAF that is expected to be completed in December 2025. This concrete face rockfill dam (CFRD), which stands 213 metres tall, will be equipped with four 200 MW Francis turbines to generate 800 MW of hydroelectric power. The dam reservoir will provide irrigation water to the new Gross Command Area of 24,450 acres and Cultivable Command Area of 16,737 acres in the Charsadda district’s Mohmand, Malakand, and Tangi tehsils.

The recent floods that have wreaked havoc across Pakistan, however, have not spared the under-construction Mohmand Dam either. According to media reports, due to the extremely high floods, the protection dyke at the inlet of the under-construction Diversion Tunnels was overtopped and then breached. As a result, the diversion tunnels were flooded. Fortunately, other construction sites were not severely damaged by the floods.

Furthermore, because of the early flood warning on August 25, construction teams were able to move construction machinery worth millions of rupees to safety well before the flood water could reach it.

“Only a thorough examination will reveal the truth, but I believe the delay will be only a few months. In this regard, the destruction of Munda dam poses a greater problem because the lower swat canal that emerges from the Munda Headworks will be inoperable, causing farmers in Mardan, Charsadda, and Peshawar to have difficulty accessing water,” Dr. Shakil continued.

The Munda Headworks, located on the border of Charsadda and Mohmand Tribal Districts, is one of the Swat River’s two water barrages. Amandara at Batkhela in Malakand, on the other hand, escaped the ferociousness of flood waters. The portion at the centre of the Munda headworks and the downstream bridge, both rebuilt by the Khyber Pakhtunkhwa (KPK) Irrigation Department following the 2010 floods, were again washed away during the recent floods.

The Mohmand Dam reservoir will have a Flood Surcharge storage capacity of 100,000 acre feet. Flood water will be controlled by a spillway designed for a maximum flood of 27,427 cumecs (968,575 cusecs). When completed, it will reduce downstream flood damage in the Charsadda, Nowshera, and Peshawar districts.

According to consultant flood studies, the recorded flood at Munda Headworks during the 2010 historic flood was 9,900 cumecs. Following the completion of Mohmand Dam, the attenuated flow below Mohmand Dam at Munda Headworks of the same intensity is expected to be 6,000 cumecs. The project’s estimated annual flood mitigation benefits are Rs. 1.5 billion.

Furthermore, water is scarce in Peshawar, Nowshera, and Charsadda. Peshawar’s water table is dropping one metre per year. In addition to providing 300 million gallons of drinking water per day to the densely populated Peshawar city, the Mohmand Dam will also help recharge the underground water resources in the aforementioned districts.