By Arshad H Abbasi
Just a month or so there was a lot of debate in Pakistan on the issue of water conservation and storage. And now the situation has changed so much that there is now too much water. Torrential rains and heavy flooding have not stopped yet and some parts of the country have experienced extensive damage and many people have lost their lives. There is one silver lining to this otherwise dark cloud and that is that the floods and heavy rainfall have opened an opportunity to look at flood management solutions anew.
The solution lies in ecologically sustainable water management by shifting reactive policies to proactive ones, by adopting a better approach on flooding, as it is not only a matter of water management alone. It is also a matter of land use planning and soil protection apart from damage to properties, human lives as well as crops. It is strongly linked with policies to use floodwater for recharging depleting groundwater as most monsoon rains rush out — unused — to the sea.
To mitigate flooding propensity in Pakistan, both the government and the people will have to change their view of things as well as adopt best management practices (BMPs) in agriculture, forestry, land-use planning, water resources management, and urbanisation.
The framework developed for flood management is an archaic methodology of constructing of embankments, dykes and flood walls including a flood forecasting system and non-structural measures of early flood warning. No doubt the Pakistan Meteorological Department is doing its job in an efficient manner but the basic fault lies with the flood mitigation strategy, as presently the structural measures are the focal point of concerned departments, federal or provincial.
Analyses of climate data of the northern region of Pakistan including Murree shows that during the last ten years the intensity of rainfall and rate of evaporation has increased, while the number of rainless days is decreasing. The changing snowmelt patterns of glaciers which is responsible for flash floods. To avoid flash floods there is a need for protecting the trees from being felled. The ministry of environment has spent millions of rupees planting trees from 2001 to 2006 to protect the Tarbela watershed but has failed in its efforts. A report by the Forest Institute of Peshawar says that unprecedented deforestation has occurred in the Northern Areas, Azad Jammu and Kashmir and NWFP at an alarming rate of 69,600 hectares per annum. It adds that if the deforestation continues at this rate whatever is left of the tree cover will disappear in another five years. In many places trees are recognised as having an important role to play in the fighting floods. One mature conifer tree has the capacity to retain water and fight floods by reducing the amount of runoff. North America and some Asian countries have successfully incorporated bio-retainment techniques to control floodwater.
The UNDP and Food and Agriculture Organisation (FAO) studied the behaviour of the soil at Ghoragali near Murree. Run-off of water was observed in different conditions like, bare land, land with grass, undisturbed soil with thick forest. It concluded that that 91 per cent of water ran off immediately to generate flash floods. These flash floods denuded soil from trees but where the land was covered with thick forest only 12 per cent of the water went to streams and the rest was absorbed. This shows that land-use and water have a natural role to play in flood risk management, that forests have the ability to slow torrential rainfall. They do this by acting as sponges, first absorbing and retaining the floodwater only to slowly release it later. Thus, the loss of forest cover leads to double loss — more damage from flooding and a reduced recharge of aquifers.
Another distressing part of floods this year, other than loss of life and valuables, is the ten million acres of water which escaped from Kotri without being utilised to artificially recharge our aquifers (ground reservoir) eventually flowing unused into the sea. According to a recent World Bank report the running dry, growing demand and over exploitation and continued depletion of groundwater at the rate of ten metres per annum pushed Pakistan from a water stress to water scare country. Groundwater accounts for almost half of all irrigation requirements and reinstatement of this unlimited reservoir by preserving its recharge area, including protection of watershed was the responsibility of Pakistan which involves the mapping of the recharge zone of our aquifer by using simple isotopes’ method. Nevertheless, it is regretted that due to prevailing incompetence in some organisations this proved as a burden on the national exchequer.
Another great dilemma with our water related organisations, eg Pakistan Council of Research in Water Resources, is the huge wide gap of mandate and net deliverable. The organisation has never come up with any concrete research related to water resources. The PCRWR should adopt the best management practices in water resources management. Instead of spending 155 million rupees to create public awareness about water conservation, the council should lead by example. It seems to be unaware of depleting groundwater in the country and which will probably cause a lot of problems in future. The council needs to consider ways to recharge aquifers by using floodwater through cost-effective and efficient techniques of aquifer storage and recovery.
Aquifer storage and recovery is a technique whereby floodwater can be stored below the ground for later extraction and reuse. Aquifer storage and recovery can function in the manner of a traditional surface reservoir. The main advantage of this simple technique is that it is a natural method to remove ground water contamination and even brackish water is flushed by displacement with fresh water and replenish it with safe and drinkable water. Sindh and southern Punjab face the problem of having saline water underground which is unusable. In such a situation, the technique of aquifier storage and recovery may well help in making such water safe to drink.
India also used the same methodology to use floodwater to conserve and rejuvenate falling groundwater reserves by channelling monsoon river flows that simultaneously recharged the underlying aquifers. As a result, declining water tables have been arrested, pumping costs for irrigation have been reduced and the agricultural productivity of the country has improved. This approach has the potential to improve farmers’ livelihoods in our areas as the cost of pumping reduced considerably and there is no burden on state to build big dams and canals to carry the water to irrigate remote areas.
The economic cost of extreme weather and flood catastrophes is severe. Therefore preserving and replacing the felled trees with new ones will help re-stabilising water flow and storage. And develop a strategy to harness enormous hydel energy, which will not only provide cheap alternate energy to the people but stabilise carbon dioxide levels and control climate changes to avoid extreme natural calamities.
The writer is a visiting research fellow at the Sustainable Development Policy Institute in Islamabad. Email: firstname.lastname@example.org