Changes in Indus Basin: A Diagnostic Analysis

At a time when the global discourse about water is getting centred around restoring rivers to function as healthy working systems, the discourse in India has again reverted around reviewing and even abrogating the World Bank brokered Indus Water treaty (IWT) signed by India with Pakistan in 1960.  Following  a fiery atmosphere of intensified political conflict between the two neighbours, the river Indus is unfortunately getting seen as a potential political tool. Of course the Government of India has made it clear that it is not in favour of abrogation of the treaty, but of making maximum use of its eligible water share within its framework.  This stand may serve to assuage the people of Jammu & Kashmir who have felt their developmental potential sidelined under the treaty restrictions, but will it assuage the river itself which due to poor management of its resources has turned into a carriture  of its original vibrant free-flowing self?

The Indus basin which once hosted the sub-continent’s oldest and most sophisticated civilization, and today supports a region marked with huge population pressure and immense economic development aspirations, has become one of the most depleted river basins of the world.  Out of an approximate 180 billion cubic metres (bcm) average annual discharge, only around 35-40 bcm flow into the sea, and during certain parts of the year no water reaches the sea.  Pakistan and India withdraw more than 90% of the surface water and extensively mine the groundwater only to support an agriculture system that has one of the world’s lowest water productivities in terms of crop per unit of water and per unit of land.

The Indus Water Treaty, regarded as an example of successful water-sharing conflict that has withstood the test of 3 wars, is basically a water-partitioning agreement  wherein 3 western rivers of the Indus river system were allocated to Pakistan and 3 eastern ones to India. It permits India limited access to the western rivers for irrigation, hydro-power generation and transport with restrictions and conditions aimed at safeguarding Pakistan’s interests. The technical density and nature of division of water, aggravated by the political conflict between India  and Pakistan,  has subjected the treaty to substantial wear and tear.  With the treaty having little  embedded capability of  handling variability arising from environmental degradation, uncertain weather patterns and changing climatic conditions, there is a case for reviewing and upgrading it into a more co-operative water management framework that will increase the viability of irrigation as well as help restore  the river into a healthier functional system.

Vital Statistics of the River: A Grim Picture

The Indus drains over a million sq kms covering the 4 countries of Pakistan, India, Afghanistan and India.  With 40% of its watershed being located at elevations of over 2000 metres above sea-level in the relatively young Himalayan mountains, the river is one of the highest carriers of sediment load in the world.  It carries an average of around 510 tonnes/km2/year in comparison with hardly 146 tonnes/km2/year by Brazil’s Amazon river and 38 tonnes/km2/year by the Nile, two  of the world’s longest rivers.  However much of the nutrient rich sediment that used to annually nourish the delta lies trapped behind dams and barrages, adversely affecting storage capabilities of reservoirs, considered as irrigation lifelines in highly seasonally variable river flows, and damaging delta ecosystems.

About 70% of Indus water flow comes from glacial and snow melt with rainfall accounting for the remaining 30%.  Around 85% of water flows into Indus catchment occurs within a period of 3-4 months in summer with flows increasing by over 20 times at peak time due to glacial & snow melt as compared to the drier winter season.  Therefore water flow in Indus is highly seasonally variable which requires sufficient storage capacity so that excess stored water can be made available during lean times.  However the per capita storage per year in Pakistan is hardly 150 cubic metres (cm) amounting to just about 30 days of the river’s annual discharge , while dams in India can store around 120-200  days of annual flow, both of which compare poorly with China’s per capita annual storage of 2200 cm and US’s 5000 cm.

The river irrigates an average of 2,28,694 sq kms i.e. around 21% of the basin area of which around 60% lies in Pakistan and 38% in India.  An agriculture life-line for Pakistan and for Punjab & Haryana in India, the Indus basin contains the world’s largest contiguous irrigation system with several storage reservoirs, barrages, inter-river-links and over a 59,000 km long irrigation canal system with over 1.07000 km long watercourses.  But the viability of irrigated agriculture in the basin is threatened by multiple factors painting a grim picture for food security in a scenario where 40% more food would be  required to feed  the increasing population by 2025. While agricultural yields have increased after the Green Revolution, a water-intensive cropping pattern coupled with poor irrigation efficiency and bad on-farm management practices have continuously decreased the water productivity.

A river with a dynamic geomorphological regime in the past, today Indus  is one of the most engineered rivers with nearly all of its surface water being weir-controlled for irrigation.  Over the last 60 years since the signing of the IWT, the quantity of water flows into the delta has been reduced to a peak of around 35-40 bcm, hardly a tenth of its historical flows.  More importantly out of the 400 million tonnes of nutrient rich sediment that used to flow to the delta, hardly 100 million tonnes today awash the coasts. This water and soil squeeze has led to dying fisheries, coastal erosion, mangroove destruction and salt-water ingress into coastal regions with adverse impacts on livelihoods and ecosystems. In the plains, with primarily embankment-based flood control strategies, the river finds itself cut off from its flood plains, while silt accumulated due to dams and barrages have aggraded the river resulting  in  a super-elevated river in certain areas making it particularly vulnerable to avulsion and floods. Moreover its flood containing capacity has been weakened through rapid draining of wetlands and marshes, underlining the need for moving from aggressive  river-controlling strategies to river management strategies to restore their healthy functionality.

Basin Management: A Diagnostic Analysis

Traditional approach for river management is  essentially hydro-centric wherein the river basin was viewed as a complex physical system based on inter-relationships between the hydrological and geomorphological characteristics of the river.  It looked at water as a resource to be exploited for economic development and therefore emphasized maximum possible yield through techno-scientific applications and the development of mechanisms for most effective water allocation among users.  Applying this approach, the traditional water management and distribution system in the Indus basin was gradually replaced with dams and canal irrigation systems based on modern technical and engineering knowledge, bypassing local water management knowledge and practices.  Starting with ‘colonial canal colonies’ during British time, the techno-engineering approach was aggressively continued by nationalist water engineers of both India and Pakistan after signing of the IWT in 1960.  No doubt the the hydro-centred approach successfully turned the arid Indus plains into thriving agricultural farms, but the transformation has been achieved at the cost of massive environmental degradation, elimination of pastoral economy and marginalisation of small farmers, replacing a diversified cropping pattern with a commercialized monoculture and bypassing traditional water management knowledge and practices.  The once free and volatile Indus which had withstood a mixture of histories, cultures and environments found itself trained and disciplined into straight cemented irrigation channels driven by quantitative hydraulic data and rational models of river control.

IWT:  Paragon of Techno-Engineering Approach

The IWT with its focus on engineering technicalities and legality of water-use by signatories  India and Pakistan is a reflection of the single-sector oriented  hydro-centred techno-engineering approach of river control of the times. Signed in an atmosphere of suspicion amidst Pakistan’s lower riparian anxiety, aggravated by the antagonist political relationship between the two countries, the nationalist engineers and statist negotiators did not concern themselves with more contemporary principles of equitable water sharing or holistic management of the river system.  Instead they divided the river system apportioning 3 whole western rivers to Pakistan and 3 eastern rivers to India with  non-consumptive access to India to the western rivers with maximum permissible  storage of 3.6 million acre feet for irrigation, hydropower generation  and transport.  The treaty is thus more of a conflict-avoidance techno-legal protocol devoid of any ecological or social perspective on the river system.

Water management treated on a techno-engineering-centred approach as opposed to socio-ecological-centred approach tends to ignore the organic nature of water and its relationships with people and livelihoods.  It also tends to reduce the entire river system into mere volumes of flowing waters.  Neglecting the organic nature of water and its relationships with people leads to inability for equitable sharing and preserving the precious resource.  The engineering-dominated supply -side approach focused on water resource development giving scant attention to the manner in which water was used.  The result is that the largest irrigation system in the world is plagued with large scale resource degradation including water-logging & salinity, over-exploited groundwater, poor irrigation efficiency, low water consumption values, lowest water productivity and significant livelihood impacts and biodiversity damage in the delta ecosystems.

Acute Resource Degradation: Water-logging, Salinity and Declining Water-tables

Agriculture experts say that due to diversion of water for irrigation, about 16 million tons of salt which would have drained into the sea along with the water gets accumulated on the irrigated land annually.  Out of 16 million tons only about 2.2 million tonnes gets deposited in a series of evaporation ponds, which means that about 1 tonne of salt per hectare is added to the soil every year.  Absence of natural drainage due to flatness of the plain and insufficiency of the over 15000 km constructed surface drainage has resulted in poor drainage resulting in accumulation of salinity in the basin.  Salinity levels get worsened through the practice of concurrent use of surface and ground water by farmers in an attempt to reduce salinity in the irrigation water and thus avoid  soil  salinization.  Groundwater ensures a reliable, timely, demand-dependent and self-controlled water supply as against the gravity-based low-intensity continuous irrigation supplied by the canal authorities.  In the absence of sufficient knowledge about proper mixing ratios of surface and ground water, farmers at canal-head areas who actually get around 30% more surface water freely use groundwater resulting in water-logging, while farmers at tail-end areas supplement the depleting surface water that reaches them with poor quality groundwater thereby aggravating salinity.  While seepage through unlined canals remain another potent source of water-logging, declining water-tables increase groundwater salinity due to redistribution of salts in the underground acquifer.  An estimated 4.5 million hectares out of total around 16 million hectares of irrigated cropland is currently affected by salinity with the problem being acute in the delta region of Sindh where over 54% of irrigated cropland  is salinity-affected. Agriculture  economists say that land degradation due to water-logging and salinity is decreasing crop production potential in the basin by an estimated 25% valued at a loss of around 250 million dollars per year.

In both India and Pakistan dependence on groundwater is almost equal or exceeds dependence on surface water.  An  analysis of net irrigated area across the basin shows that only 28% of total area is irrigated by surface water canals while 72% is irrigated  by both surface and groundwater.  In 1960 groundwater accounted for only 8% of agricultural water, but today groundwater accounts for around 60-65% of agricultural water across the basin. India has around 1.9 million tube wells while Pakistan has around 1.2 million of which 80% are electricity operated and around 20% diesel-operated.  The multi-fold increase in electricity-operated tube wells in both India and Pakistan during the last 3 decades has been due to subsidized electricity.  Groundwater exploitation which is over 150% across the basin with average water-tables decline of 1.5m/y has affected groundwater quality in irrigated areas as well as crop production in rain-fed areas due to decreased drought resilience.  In Indian Punjab, agriculture experts say 110 blocks out of 138 have been over-exploited i.e. groundwater drawls of over 100%, 3 blocks are in critical stage with groundwater drawls between 90-100% and 2 blocks in semi-critical stage with drawls ranging from 70-90% . Only 23 blocks located in the foot-hills region or areas of poor water quality are safe.  More dependence on predictable and self-controlled groundwater has given India and Pakistan higher yields but groundwater dependence comes with grave environmental externalities.

Low Water Productivity:  Symbol of Poor Water Management

Though the basin commands over 59,000 km long canal network with over 107000 km long watercourses, irrigation efficiency is only around 35-40% from canal head-waters to crop-root zone.  Around 50% of total surface water inputs are lost to canal and water course seepage, filed application losses and evapo-transpiration. Besides seepage through unlined canals, poor on-farm practices like water-inefficient traditional land-leveling methods, tillage, inefficient irrigation systems including overland channels and flush irrigation has resulted in water consumption values of hardly 15-20%, one of the lowest in the world.  Water productivity in Pakistan for wheat is hardly 0.5kg/cubic mts of water as against 1.0kg/cubic mts of water in India, both of which compare poorly with California’s 1.5kg/cubic mts of water.  However it must be mentioned that agricultural yields have increased substantially in the basin since the Green revolution with wheat yields increasing 125% and rice yields by around 175%.

Sustainable Water Management: Only Way Ahead

There is an absolute and urgent need for more prudent water management both from the demand and supply sides to improve irrigation viability and long-term sustainability of irrigated agriculture in the basin.  But since 90% of the annual river discharge is already being withdrawn, supply side augmentation can only be done through increased water efficiency.  Demand management remains the key to better water management in the basin. Changing cropping patterns to reduce acreage under water-intensive crops like rice, wheat, sugarcane, and cotton in favour of less water-intensive but high-value crops like oilseeds, maize, pulses, vegetables & fruits is necessary.    There is need to limit rice cultivation, specially in water-scare and salinity-affected delta areas in the Sindh region, to domestic consumption needs so that virtual water export through rice exports is reduced. Improved water-saving farming practices like precision land-leveling, mulching & bed-planting in case of wheat crop which saves about 18-25% of water, alternate wet and dry irrigation in rice crop or direct seed rice plantation both of which methods save about 25% water should be encouraged and incentivized   Similarly prevention of water losses by replacing unlined open water courses with underground pipes coupled with increased use efficient irrigation systems like drip and sprinkler can vastly increase irrigation efficiency.  The good news is that farmers are increasingly adopting resource conservation technologies like zero tillage drills and laser land leveling with appreciable increases in yields.  Approximately 54% of farmers in Punjab use zero tillage drills, while around 90% use laser land leveling.   However drip irrigation use in both Punjab and Haryana is just about 0.5% against a potential of around 6%.  The percentage of sprinkler irrigation in Punjab is around 0.5 % compared to a high of 30% in Haryana.

In view of over 150% average groundwater exploitation across the basin there is an imperative need for acquifer management through a balance between discharge and recharge. Artificial recharge of groundwater through means like construction of rain-water conserving re-charge ponds in farms, recharge shafts along highways, roof-top rainwater harvesting by urban and rural households and digging and maintenance of village ponds could go a long way in sustainable management of groundwater overdraft in the basin.  To tackle water-logging problems in canal-head areas and salinity in canal-tail areas, upstream farmers should be encouraged to use more groundwater which is fresh and tail-end farmers to use less ground-water which is saline.  But to change the current water-use practice of excessive surface and groundwater by head-end farmers and excessive ground-water by tail-end farmers, canal authorities have to regulate canal water flows to ensure that tail-end farmers get timely and sufficient water. It  may be difficult to quickly change long-standing water-use practices, but logical motivation programmes could lead farmers towards the needed change.  Similarly logical motivation is required to combat salinity through methods like  promotion of use of gypsum or organic matter or acids or planting bio-drainage trees like poplars, eucalyptus or growing salinity-resilient grasses or fodders also useful for livestock.

New Compact for Sustainable River System Management:

Sustainable management of the river system requires a renewed Indus Compact which will effectively de-centre the technical engineering approach based on expertise of water engineers, and harness instead the expertise and experiences of a whole lot of social constituencies across the basin.  This will involve a co-operative dialogue between different river-based communities on either side of the border such as fishermen, irrigation-dependent farmers, river ecologists, water historians, sociologists, water experts, agriculture economists, etc.  These plural narratives can impart the new Indus Compact with the much needed social and ecological perspective, and has the potential to transform the  hydro-politics of the basin into  mutually beneficial co-operation aimed at  more prudent management of the basin’s fast depleting water resources, besides addressing environmental degradation issues as well as climate change challenges..


Leave a Reply