Any plan for flood rehabilitation needs to consider drainage and climate change challenges
ollowing devastating floods that hit the country this year, Pakistan is now moving toward flood mitigation and rehabilitation of the disaster-affected communities and areas. In the months to come, the government will be spending millions of dollars it has received and expects to receive as international aid for flood mitigation and rehabilitation.
Will this spending on flood mitigation and rehabilitation reduce the country’s vulnerability to future floods? The answer to this question lies in the overall understanding about floods and approaches to disaster mitigation and rehabilitation strategies on part of policy makers, who will be spending the money.
Some policy-makers see flood as a disaster that can be avoided by building structures like dams, embankments and drains. Flood mitigation and rehabilitation efforts under this approach are limited to plans and actions to rebuild damaged houses, irrigation structures, schools, hospitals, roads, rails and other infrastructure to restore lives and livelihoods of affected communities and the national economy.
The importance of structures in dealing with floods is central to the imagination of these policy makers. Not appreciating the ways the structures exacerbate the vulnerability of whole communities, they argue: “Pakistan would not have faced the devastation of this extent had it built more dams over the past decades.”
One may ask whether the existing dams, irrigation infrastructure and auxiliary drainage structures have provided protection in the relevant areas. The fact is the irrigation infrastructure has been obstructing natural drainage and causing floods in the Indus basin.
Balochistan was the first province this year to be affected by torrential monsoon rains that lashed the country and caused flooding. By August, more than 50 dams had been swept away by rainwater in Mastung, Qila Abdullah, Chaman and Quetta.
The irrigation infrastructure laid out under Chashma Right Bank Canal (CRBC), Kachhi Canal and Gomal Zam Dam projects has been obstructing natural drainage of hill-torrent in trans-Indus Damaan area between the Suleman Range and the Indus River. Thwarted by these irrigation structures, the ferocious hill-torrents changed their course and inundated many towns and villages, wreaking havoc in Rajanpur and Dera Ghazi Khan, (south Punjab), Tank and Dera Ismail Khan (Khyber Pakhtunkhwa) districts.
Why could the Gomal Zam Dam not protect Tank district and Kulachi tehsil of Dera Ismail Khan district from the recent rain-induced floods?
In Sindh, the Left Bank Outfall Drain (LBOD), structural interventions in the bed of Dhoro Puraan, Nara Canal, MNV Drain and Right Bank Outfall Drain (RBOD) have been blocking natural drainage.
Though the recent floods were caused by unprecedented monsoon rains and not by river inundation we need to understand the overall drainage crisis in the Indus basin.
The huge irrigation and drainage network developed in the Indus basin over a century and a half ago has created an unprecedented drainage crisis. The construction of the storage reservoirs, barrages, weirs and other engineering works across and along the Indus River has seriously obstructed natural drainage in the Indus basin — both in low-lying flood plains and highlands.
The river beds and hill-torrents that developed over centuries have been squeezed into narrow passages, not allowing peak floods to pass smoothly. For instance, the Indus bed previously spanned over 14-20 kilometres in the Khyber Pakhtunkhwa plains, southwestern Punjab and Sindh before the advent of the modern irrigation regime. It has now been reduced to not more than 2 kilometres.
In addition, the accumulation of silt in the reservoirs as well as the riverbeds has reduced the capacity of rivers and increased velocity and therefore, bank erosion. The development of canal and drainage infrastructure has obstructed the drainage of streams and hill torrents.
Pakistan’s recent floods have been attributed to extreme weather patterns caused by climate change. Pakistan is also prone to climate change induced calamities like glacier-melting.
Any policy and plan for flood mitigation and rehabilitation needs to consider the challenges of drainage and climate change, which the country currently faces. Instead of sticking to a structure-centric approach, the policy makers should come up with more innovative solutions. They may have to learn from the experiences of other countries and adopt new climate-friendly technologies.
The writer is an anthropologist and a development professional