Global freshwater scarcity, exacerbated by unsustainable use, affects water and food security. Harnessing non-conventional water sources, conserving ecosystems, and understanding the water, food, and energy nexus are vital for sustainability.

Globally, freshwater resources cover only 0.8 percent of the surface area, of which over 70 percent is used in agriculture. The limited freshwater resources are neither being managed nor used sustainably. This unsustainable use of freshwater resources greatly impacts the world's water and food security, particularly the Global South. Climate change and climate variability have further aggravated the situation. Due to the increase in population, urbanization, and agricultural and socioeconomic activities, freshwater demand is estimated to increase by over 40 percent by 20301. Pakistan's economy is largely dependent on water. Increased population and related activities put great pressure on freshwater resources. By all water scarcity indicators, it has become a water-scarce country. The International Monetary Fund (IMF) has also ranked it third amongst the most affected countries by an acute water shortage2. 
Over 93 percent of the available water is used in agriculture. This is the sector where maximum losses occur. For example, more than 60 percent of water is lost during conveyance and application in the field, and the crops use less than 40 percent. Groundwater provides more than 60 percent of water for agriculture, more than 90 percent for domestic and almost 100 percent for industrial purposes. Groundwater serves as a buffer against drought, climate change, and floods. Nevertheless, this resource requires a more sustainable utilization. Due to the absence of a groundwater management system, individuals can install any number of tubewells of varying sizes and depths, extracting any amount of water. Consequently, groundwater depletion and water quality deterioration are prevalent in many canal commands and nearly all urban sectors.
The unplanned expansion of cities and the cutting of trees for the construction of roads, buildings, and related infrastructure are transforming eco-friendly lands into concrete jungles. This ultimately diminishes groundwater recharge and contributes to increased urban flooding. Consequently, groundwater depletion is observed in almost all urban centers. For instance, groundwater is depleting at approximately one meter per year in Islamabad, half a meter in Lahore, and about six meters in the Quetta valley3. 

Groundwater serves as a buffer against drought, climate change, and floods. Nevertheless, this resource requires a more sustainable utilization. Due to the absence of a groundwater management system, individuals can install any number of tube wells of varying sizes and depths, extracting any amount of water. Consequently, groundwater depletion and water quality deterioration are prevalent in many canal commands and nearly all urban sectors.

How to Address these Challenges?
Pakistan's water issues are complex and are compounded further by climate change. There is a need to take stern action before it is too late. The following sections will discuss some areas that need immediate attention from all the stakeholders. 
Improving the Efficiency of the Agriculture System 
The irrigation system was initially designed to distribute water equitably to all users in the command area, maintaining a cropping intensity of approximately 60 percent. However, the cropping intensity has surged to over 150 percent, intensifying pressure on available water resources. Additionally, more than 60 percent of water is lost within the system, exacerbating water scarcity issues, particularly towards the tail end. Consequently, tail-end users face challenges in accessing canal water, leading to increased reliance on the groundwater, elevated water-table depth, and reduced profitability due to higher costs associated with tubewell installation and operation. The most commonly utilized centrifugal pumps become economically impractical as the water-table depth rises. Groundwater quality is declining due to the intrusion of saline water from deeper depths and adjacent saline water areas. The utilization of saline groundwater leads to secondary soil salinization, a gradual buildup that takes a considerable amount of time to reclaim once soils are salinized.
The average yields in Pakistan are far lower than the potential yields. For example, average wheat and rice yields are 2,276 and 1,756 kilograms per hectare (kg/ha), respectively. In addition to water shortage, lack of inputs, poor irrigation practices, and secondary salinization are the other major factors in low crop yields. The water productivity of crops is also far below its achievable levels; perhaps it is the lowest in the world. It is 0.5 kilograms per cubic meter (kg/m3) for wheat compared with 1.0 kg/m3 in India and 1.5 kg/m3 in the USA4.
Similarly, the water productivity of maize and rice is also very low (0.3 kg/m3). The water productivity of maize is the highest in Argentina (2.7 kg/m3). The potential gap in the water productivity of various crops shows a tremendous scope for improvement that can help increase both horizontal and vertical expansion of agriculture4,5.
As no more water is being injected into the system, increasing water productivity in all water-use sectors is the only option. The agriculture water productivity can be increased by increasing the crop yield or reducing the water applied. In irrigated areas, there is little potential for further increasing the crop yield due to decline in potential areas and reduced marginal benefits. However, there is great scope in increasing water productivity by reducing the water applied through these following simple methods and techniques that can help increase water productivity significantly:
▪   Precision land leveling 
▪   Proper layout of the field 
▪   Appropriate irrigation methods such as bed planting
▪   Adopting proper irrigation scheduling
Pressurized irrigation systems such as sprinklers and drip have the potential to achieve high application efficiency and water productivity. However, their installation and operational costs are very high compared to surface irrigation systems. In Pakistan, a weekly rotational canal water supply prevails where conversion from surface to pressurized irrigation is neither economically viable nor socially acceptable. Since the early 80s, several projects have been implemented by various federal and provincial agencies. However, none of these projects could provide the desired results due to the following main reasons: 
▪   High capital cost
▪   Non-availability of local material
▪   No backup support
▪   Complicated and over-designed systems
▪   Small land holdings
▪   Farmer's misconceptions about the system
▪   Lack of knowledge about irrigation scheduling
▪   Flat rate of electricity in Balochistan4
Therefore, for installing these systems, selecting the right area, the right crop, the right farmer, and the right material is very important. Moreover, the system's design should be simple so that a common farmer can easily operate it. Potential areas for these systems include the Pothwar Plateau, desert and semi-desert areas, uplands of Balochistan, riverine belts, greenhouses, and tunnels4.

Groundwater quality is declining due to the intrusion of saline water from deeper depths and adjacent saline water areas. The utilization of saline groundwater leads to secondary soil salinization, a gradual buildup that takes a considerable amount of time to reclaim once soils are salinized.

Community Engagement 
Involving all the stakeholders in planning, implementation and monitoring is very important. The stakeholders include policymakers, planners, academia, professionals, executors, service providers, and the users (community). However, in Pakistan, the top-down approach (a trickle-down approach) is adopted, and the most important stakeholder–the user communities–is neglected. Due to this reason, there is neither ownership nor any involvement of the users. As a result, most of the projects and water conservation and management programs are implemented with sub-optimal success and unsustainability of the interventions introduced. 
The Agriculture Service Provider (ASP) is another crucial stakeholder that is often overlooked. The ASP serves as a link between professionals and farmers (users), acting as a skilled or semi-skilled worker who offers services to farmers at reasonable costs. They acquire knowledge from professionals and translate it into action by providing services to farmers. However, ASPs also require training and capacity building to enhance their ability to deliver services. For example, cultivating crops on ridges or beds is crucial as it conserves a significant amount of water, enhances crop yield, and subsequently increases farmers' net income. However, over 90 percent of farmers in Pakistan own small land holdings (less than 5 hectares) and cannot afford to purchase ridge or bed planters. The ASP plays a vital role in offering timely and cost-effective services to these farmers. However, if the ASP is not well-trained and lacks the knowledge to calibrate machines (e.g., bed planter) for the desired seed rate and uniform seed placement, all his efforts may fail, potentially undermining farmers' confidence in new interventions. The same applies to other services like installing tubewells, drip and sprinkler irrigation systems, laser land leveling, and using combine harvesters. Therefore, involving local communities and enhancing the capacity of ASPs are crucial for the success and sustainability of any water management practice.
Water Policies and Governance
Water and related policies serve as overarching principles for assessing, regulating, managing, and governing water resources. Fortunately, Pakistan has endorsed several national policies, including the National Water Policy 2018, the National Climate Change Policy 2012 (updated in 2021), and the National Food Security Policy 2018. Additionally, provinces have approved various policies, strategies, and water-related legislation such as the Punjab Water Policy 2018 and Punjab Water Act 2019, Sindh Water Policy 2023, Balochistan Integrated Water Management Policy 2006 and Groundwater Rights Ordinance in 1978, Khyber Pakhtunkhwa (KP) Integrated Water Management Strategy 2019, and KP Water Act 2020, among others.
These policies and related documents are very good and cover almost all aspects of water resources development, management, and governance. However, despite these policy documents, a significant breakthrough has yet to be made in the water sector. This is mainly due to the typical approach of build-neglect and rebuilds, as during the last half-century, the maximum focus has been on irrigation infrastructure development.
Moreover, in Pakistan, governance is generally perceived as a set of policies, laws, rules, and regulations. However, in the true sense, these legal instruments are only one governance component. Governance is a process involving strong science-based knowledge supported by legal instruments. Figure 1 shows a process for the better management of groundwater resources. Assessment and monitoring of the resource in time and space is crucial and a starting point for any groundwater management effort. 
Unlike surface water, groundwater resources are invisible and are least understood and focused. Each year, World Water Day (WWD) is celebrated on March 22 with a unique theme. During 2022, the theme of WWD was “Groundwater: Making the Invisible Visible”. Assessment and monitoring of groundwater (Figure 1) helps make the groundwater visible, such as how much total groundwater is available, the specific yield of the aquifer, and how water quantity and quality varies over space and time. This information also helps identify hotspots and bright spots. Once hotspots and bright spots are known, informed decisions can be made using legal instruments, ultimately leading to sustainable groundwater management. Therefore, only legal instruments are not sufficient unless supported by science-based evidence. Hence, such efforts must be led by those who have the knowledge and understanding of the system rather than those who merely have management experience. 
Use of Non-Conventional Water Resources 
Over time, the gap between water availability and demand has increased. In the near future, no more freshwater is expected to be added to the system. Therefore, this gap can be filled using non-conventional water resources such as wastewater, hill torrents, rainwater, drainage effluent, and saline groundwater (Figure 2).
It is estimated that more than 2.5 MAF of municipal and 1.5 MAF of industrial wastewater is generated annually, and only 3 percent of that is claimed to be treated, whereas 1.5 MAF is disposed of directly into water bodies. About 30,000 hectares of land are irrigated with wastewater, and 25 percent of vegetables consumed in Pakistan are produced with wastewater irrigation. The contaminants from the untreated wastewater directly or indirectly enter the food chain, resulting in multiple diseases.
One of the major reasons for the non-treatment of wastewater is the centralized approach. Water and Sanitation Agencies' approach has been to collect wastewater from the whole or part of the cities and treat it. This requires huge infrastructure and high operational and management costs. Due to the non-availability of operation and maintenance costs, the wastewater treatment plants constructed in Karachi, Lahore, and Islamabad are either non-operational or working at sub-optimal levels. Therefore, the decentralized wastewater treatment systems at or near the pollution sources must be constructed and operated by applying the polluters pay principle. This would force the polluters to reduce, reuse, and recycle the wastewater. This would also help achieve Sustainable Development Goal (SDG) 6 Target 6.3, which says, "By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and increasing recycling and safe reuse globally."
Similarly, hill torrents have a huge potential (about 19 MAF). Proper harvesting and management of this vital resource will not only help mitigate the gap between water supply and demand. However, they would also improve the country's food security and reduce flooding, which has become a regular feature now. According to the National Food Security Policy 2018, the untapped potential of about 19 MAF generated from hill torrents (Rod Kohi), if harvested, can bring about 7 million hectares (Mha) area under cultivation in Balochistan (67 percent), KP (13 percent), Punjab (8 percent), Sindh (8 percent), and erstwhile FATA (4 percent). 
Rainwater is another non-conventional resource that, if harvested, can help reduce the gap between the water supply and demand, replenish the depleting aquifers, and mitigate the impact of climate change, drought, heatwaves, and floods6. Moreover, about 10 MAF of the drainage effluent is available. The disposal of it has been an issue. Left Bank Outfall Drain (LBOD) and Right Bank Outfall Drain (RBOD) were constructed to dispose of the drainage effluent. Despite huge investments, these projects could not achieve the intended objectives. The drainage effluents are mostly of marginal water quality and can be used directly or conjunctively with fresh water. Moreover, it can be used to irrigate salt-tolerant crops, grasses, fruit trees, forest trees, etc., for which sufficient knowledge is available.
Ecosystem Conservation 
The ecosystem is a dynamic arrangement of living things with non-living things and is one of the most important components of the planet Earth. It connects humans with nature, flora with fauna, soil with water and air, etc., and provides huge "ecosystem services." Ecosystems exist in various forms, including deserts, forests, rangelands, mountains, and aquatic environments. Any disruption in an ecosystem has far-reaching consequences on ecosystem services, contributing to climate change, heatwaves, droughts, floods, loss of plant and animal species, and human migration. Regrettably, unsustainable water practices, urban expansion, deforestation, and untreated wastewater discharge into freshwater bodies have resulted in the degradation of crucial ecosystems. Examples of deteriorated ecosystems include the Indus Delta, Thar and Cholistan deserts, Ravi and Sutlej rivers, and several lakes such as Kallar Kahar, Hanna, Keenjhar, etc.
The SDG 15 of the 2030 Agenda for Sustainable Development is devoted to "protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and biodiversity loss." The key to sustainable development is balancing exploiting natural resources for socioeconomic development and conserving ecosystem services critical to everyone's well-being and livelihoods. There needs to be a blueprint for obtaining this balance. However, understanding how ecosystem services contribute to livelihoods, who benefits, and who loses from changes arising from development interventions is essential. SDG 6, Target 6.6 stresses that “By 2020, protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers and lakes”. Three important national policies, such as National Water Policy 2018, National Climate Change Policy 2021, and National Food Security Policy 2018, place great importance on protecting and restoring the related ecosystems. However, there is a dire need to integrate ecosystem values into planning, development processes, and strategies to keep the ecosystems alive, healthy, and sustainable.
Water, Food, and Energy Nexus 
Water is an integral component of the food and energy system. Any decline in water quantity and quality will badly impact the food, and energy security of the country. Therefore, ensuring that everyone has access to a reliable supply of water, food, and energy is crucial to human survival and sustainable progress. The changing climate further compounds the interdependence of the three sectors on each other. Understanding and managing the complex interactions between water, energy, and food security is essential to cope with changing climate and achieve the SDGs.
Figure 3 shows an interaction with the three sectors. It is important to understand the interconnections between these systems, the challenges, and opportunities this interaction provides and the tradeoffs that can be achieved. However, strong collaboration among the various stakeholders is essential to better plan and manage these resources.
Increased population and its corresponding demands have placed significant strain on the country's freshwater resources, and climate change has heightened their vulnerability. Traditional approaches to water resource management and governance have yielded suboptimal results, lacking a substantial breakthrough. Recognizing that water security is intricately tied to food and national security, maintaining the status quo is no longer viable. Stern actions, involving all stakeholders, are imperative. 

The writer is the former Chairman of the Pakistan Council of Research in Water Resources, Islamabad.
E-mail: [email protected]

References
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