Afghanistan Water Resources Profile Overview
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WATER RESOURCES PROFILE SERIES The Water Resources Profile Series synthesizes information on water resources, water quality, the water-related dimensions of climate change, and water governance and provides an overview of the most critical water resources challenges and stress factors within USAID Water for the World Act High Priority Countries. The profile includes: a summary of available surface and groundwater resources; analysis of surface and groundwater availability and quality challenges related to water and land use practices; discussion of climate change risks; and synthesis of governance issues affecting water resources management institutions and service providers. Afghanistan Water Resources Profile Overview Water resources can be highly seasonal, and availability can vary significantly across Afghanistan. Water stress is moderate as approximately 55 percent of freshwater resources are withdrawni and the annual per capita freshwater availability is slightly higher than the Falkenmark Water Stress Indexii threshold for water stress. Snowmelt during the late spring and summer is key to replenishing water resources, particularly for major rivers in the east and northeast. Water is scarce in the deserts and steppes throughout the south and west. The Hindu Kush’s glaciers are melting due to rising temperature caused by climate change. This is reducing a natural water storage mechanism that protects against drought in the Amu Darya and Kabul River Basins. Higher evaporation rates caused by warmer temperatures will significantly reduce water availability over the course of the century. Surface water shortages during droughts are accentuated by over allocation, inadequate storage, and reservoir management challenges. Insufficient surface water storage and poor reservoir management constrain water availability for irrigation and contributes to food insecurity in the Helmand, Northern, and Harirud-Murghab River Basins. Additionally, surface water abstractions for irrigation are high relative to supply. Natural and anthropogenic contaminants increasingly threaten the viability of water sources. While comprehensive water quality data are limited, untreated municipal wastewater contaminates surface water while and open pit mining exposes surface water to erosion, sedimentation, and toxic mine tailings. Demand for groundwater often exceeds supply. Overexploitation of groundwater in the Harirud-Murghab and Helmand Basins is reducing water supply for irrigation and water table levels are declining in the Kabul and Kandahar metropolitan areas due to over-abstraction for domestic use. Groundwater quality is poor due to naturally occurring heavy metals. Arsenic contamination is extensive in the Helmand and Kabul Basins. Poor sanitation systems in urban areas, especially around Kabul, have contaminated aquifers that are abstracted for drinking water. Legal and institutional frameworks for transboundary basin management are limited and international disputes over transboundary river management impact opportunities for collaboration and financing of hydraulic infrastructure and basin conservation. Limited surface and groundwater quality monitoring impedes implementation of evidence-based policies and strategies for water management. iSDG 6.4.2 measures water stress as the percentage of freshwater withdrawals against total renewable freshwater resources. The water stress thresholds are: no stress <25%, low 25%-50%, medium 50%-75%, high 75%-100%, and critical >100%. iiThe Falkenmark Water Stress Index measures water scarcity as the amount of renewable freshwater that is available for each person each year. A country is said to be experiencing water stress when water availability is below 1,700 m3 per person per year; below 1,000 m3 is considered water scarcity; and below 500 m3 is absolute or severe water scarcity. Water Resources Availability KEY TAKEAWAYS The Kabul and Amu Darya Basins are the most hydrologically productive basins. Most precipitation is in the form of winter snowfall, which replenishes water resources during the spring and summer. Groundwater is concentrated in broad alluvial fans following the courses of intermontane rivers and is accessible to most major urban areas. This section summarizes key characteristics of surface and groundwater resources. Table 1 summarizes key water resources data and Figure 1 presents key surface water resources, wetlands, and dams. Surface Water Resources Groundwater Resources Afghanistan manages its surface waters through five Groundwater availability and accessibility varies basins: Kabul, Helmand, Harirud-Murghab, Northern, significantly across Afghanistan due to geologic and and Amu Darya.6 The Hindu Kush Mountains form the climate conditions. Most groundwater recharge is linked headwaters of all river basins. Most basins conclude their to infiltration along rivers.12 Broadly, Afghanistan’s aquifer flows in low-lying deserts, wetlands, or inland lakes and systems can be grouped into three regions.13,14 The seas. However, the Kabul River, which is a tributary of the Central Highlands (the Hindu Kush Mountain Range) Indus River, drains to the Arabian Sea. The Kabul and contains the Kabul River Basin and has three connected Amu Darya River Basins contain 83 percent of surface aquifer systems (Kabul, Paghman, and Logar) with high water.7,8 The Amu Darya River Basin includes several water tables. Their layers are highly permeable and small lakes, including the Chaqmaqtin and Zorkul in the thickness can range between 20 and 70 meters.15 There Wakhan Corridor and Lake Shiva in the north. The Amu are over 5,000 mountain springs, mostly in the upper Darya River is one of the longest and most important catchments of the Helmand River Basin, that supply rivers in Central Asia, with Afghanistan contributing 15 surface water systems.3,16 Groundwater in the Northern percent of its totals flow.8,9 The Amu Darya River is also Plain (Northern River Basin around Mazar-e Sharif) is less vital to regional agriculture and historically sustained the accessible due to naturally high salinity. There are several Aral Sea.10,11 The Band-e Amir Lakes are located west important alluvial aquifers along the Balkh, Saripul, Shirin of Kabul in the Kabul Basin. The Helmand River is the Tagab, and Qaysar River Valleys where recharge is higher. longest in Afghanistan and flows almost 800 miles before Aquifer characteristics such as thickness, depth to water reaching the Hamun Wetlands along the border with table, and the presence of freshwater are highly variable Iran.13 The Helmand Basin also contains brackish lakes around Mazar-i-Sharif, and municipal supply wells tend to and wetlands, including the Nawur and Abe Istada and be quite deep.12,17 Aquifers in the Great Southern Plain Gowd-I Zerrah. The Harirud and Murghab Rivers (Harirud- (Dasht-e Margo and Registan Deserts in the southwest) Murghab Basin) flow into desert oases in Turkmenistan.8 are not well understood but groundwater is readily available along major watercourses. Central and South TABLE 1. WATER RESOURCES DATA Year Afghanistan Asia Region (Median) Long-term average precipitation (mm/year) 2017 327 691 Total renewable freshwater resources (TRWR) (MCM/year) 2017 65,330 65,330 Falkenmark Index - TRWR per capita (m3/year) 2017 1,839 2,529 Total renewable surface water (MCM/year) 2017 55,680 55,680 Total renewable groundwater (MCM/year) 2017 10,650 10,650 Total freshwater withdrawal (TFWW) (MCM/year) 2017 20,280 20,280 Total dam capacity (MCM) 2019 2,930 22,160 Dependency ratio (%) 2017 28.72 28.72 Interannual variability 2017 2.5 2.15 Seasonal variability 2017 2.5 3.15 Environmental Flow Requirements (MCM/year) 2017 28,290 36,310 SDG 6.4.2 Water Stress (%) 2017 54.75 83.60 Source: FAO Aquastat 2 FIGURE 1: MAP OF WATER RESOURCES Surface Water Outlook KEY TAKEAWAYS Surface water is primarily abstracted for irrigation along the Kunduz, Kabul, Harirud, and central reaches of the Helmand River. Irrigation methods tend to be inefficient and total abstractions are high relative to supply. Low reservoir storage capacity impedes irrigation and compounds water stress caused by high inter-seasonal and inter-annual variability. High abstractions on the Helmand River limit environmental flows needed to protect biodiversity in the transboundary Hamun Wetlands. Surface water quality is not well characterized, but fecal contamination appears to be widespread, while a burgeoning mining sector may expose surface water to chemical toxins and heavy metals. This section describes key sources of demand and uses of surface water, and associated challenges stemming from water availability and water quality challenges. Surface water withdrawals for irrigation are high 80 percent of irrigated agriculture depends on surface 12,18 relative to water supply. Nearly 98 percent of all water. Intensive irrigation, particularly of wheat, freshwater abstractions are for irrigation and 85 percent occurs along the Kunduz, Kabul, Harirud, and central of these withdrawals are from surface water.1 Around reaches of the Helmand Rivers. Rainfed agriculture is 3 predominant in lowland regions throughout the Northern, not a member of the Ramsar Convention, but the Iranian Harirud-Murghab, and Amu Darya Basins.2 Most irrigation portion of the wetlands have been designated as a systems are community-managed canals.16 Irrigation Ramsar Site.32,33 The Hamun Wetlands almost dried up in efficiency in traditional and irrigation schemes is low (25- the early 2000s after years of drought, over-abstraction,