COMBAT WATER DILLEMAS IN URUMQI: STORAGE AND REUSE

Background

Ürümqi is the capital city of the Xinjiang Province located in the northwest part of China. It holds the title for being the world’s farthest metropolis from the ocean, and it has a semi-arid climate characterized by cold and dry winters and hot and dry summers. It is a rapidly growing megacity with a strong economy and a high population density (source).

The main source of water for Urumqi comes from surface water, specifically from the five river basins in the region. These basins include the Urumqi River Basin, the Toutun River Basin, the Baiyang River Basin, the Chaiwopu Basin, and the Alagou Basin (source). Over 50% of Urumqi’s water supply comes from the Wulabo Reservoir. This reservoir is fed by the Urumqi River, which is also known as the mother river of Urumqi city. (source). While Ürümqi is not situated directly on top of an aquifer, it is located close to many in the surrounding area. The region’s groundwater is primarily found in alluvial aquifers that are recharged by seasonal runoff from adjacent mountains. Additionally, there is a desert located on the northern side of the city, and aquifers are present beneath this area as well. These aquifers are crucial sources of water for agriculture, industry, and urbanization in Ürümqi and the surrounding areas (source).

Both surface and groundwater are recharged by precipitation. The city of Ürümqi typically receives low levels of precipitation throughout the year, with the majority of rainfall occurring between June and September. However, precipitation in Ürümqi is irregular, with occasional torrential downpours triggering flash floods and prolonged periods of dryness. On average, the city receives 100mm to 200mm of precipitation per year, which is lower than other regions of China (source).

Challenges

The climate in Ürümqi is dry, with low precipitation and high evaporation rates, leading to a scarcity of water resources. This scarcity limits local socioeconomic development, particularly in farming, husbandry, economic growth, and ecological and environmental preservation.

Glacier Melting

In recent years, Urumqi has been rapidly draining its available water sources and confronts an impending catastrophe exacerbated by a rapidly increasing population and a poorly managed environment. An important source of water for Urumqi is the meltwater from its nearby glaciers, mainly by the Tian Shan glacier and Bogda Peak. The Urumqi River, fed by the Tian Shan glacier, is one of the primary sources of urban water provision for the capital’s main reservoir (source). According to government estimates, the average temperature in Xinjiang has increased by 1.6 degrees Celsius since the 1980s, which is three times the normal rate of warming in the Northern Hemisphere. As a result, the glaciers in the region are melting at an alarming pace. (source).

Interestingly, the melting of the Tianshan glaciers is not all negative for the city of Ürümqi in the short term, particularly since the government has always placed great importance on the city’s economic development. For example, the availability of glacial meltwater has significantly supported the creation and operation of some tourist facilities in Ürümqi, such as the ski slopes on the golf course. This has aided the city’s economic development in the near term, enabling it to become a multi-billion dollar megacity (source).

However, from a long-term perspective, the human glacier issue’s scope and severity should not be underestimated. According to the Intergovernmental Panel on Climate Change (IPCC), meltwater from glaciers and periodic snowpacks supports one-sixth of the world’s population. The World Glacier Monitoring Service conducted a worldwide survey last year and found that mountain glaciers, which directly provide water to humans, are retreating three times faster than they were in the 1980s. While hundreds of millions of people are facing significant water supply disruptions due to climate change, the 4 million people in Ürümqi are experiencing a higher degree of difficulty (source). At the current pace of global warming, nearly 11,000 glaciers in Xinjiang (which is about 55% of the number of glaciers in Xinjiang) will be gone within 50 years. (source)

Physical Scarcity

The major issue in water management in Urumqi is water scarcity, particularly in meeting the demand for municipal water supply. In 2019, the total usable water resources in the city were around 1.1 billion cubic meters, with an average of less than 350 cubic meters per person, which is one-eighth of the national average (source). Due to the unique geography of Urumqi, it is challenging to find additional sources of water beyond the existing ones. The city is experiencing rapid economic and population growth, leading to a growing demand for water pipes and sewage systems. The city population rose from 3.11 million in 2010 to 4.05 million in 2020.

In order to increase the water supply, the city expanded its water pipe network by a total of 470 kilometers between 2005 and 2012 (source). The expansion of water pipes in Urumqi did not fully address the capacity issues in existing lines. As industrial land was repurposed for commercial and residential use, the 200mm and 300mm pipes installed for industrial purposes became inadequate compared to the 500mm pipes required for commercial and residential areas (source). Furthermore, the city’s planning relied on the geographic elevation differences to build water treatment plants in the southern part of the city. As a result, the old water supply system was designed to operate using gravity flow with minimal pumps and pressure stations. However, as the northern part of the city experienced rapid development and more residents moved to the southern region, there has been a rise in water demands that require higher pressure control in the pipelines. Due to the lack of pressure stations, residents in the southern area often experience low water pressure and insufficient supply, resulting in conflicts over water (source). With the ongoing expansion of the city, water scarcity issues are expected to become increasingly severe in the near future.

Wastewater Management Issues

Furthermore, Urumqi is facing challenges with the wastewater system. The problems include:

Inadequate wastewater discharge pollution
Sewage runoff due to capacity overload in the city
Clogging of sewage systems

According to the report, in 2015, 60,000 tons of wastewater were being directly discharged daily, out of which 4,000 tons were from chemical manufacturers. Additionally, it was found that the wastewater treatment plants were discharging sludge from the treatment process to forestry land (source). The direct pollutants discharge affects the water quality in rivers and soils. Urumqi suffered from sewage runoff despite a relatively dry climate and low precipitation. The city has a combined sewage system with a total of 870 kilometers that channel the wastewater treatment plants in the city. Due to the geographic feature of high elevation on the south, lower elevation on the north, and lower elevation at the city’s center, Urumqi would experience sewage runoff in the north and center of the city during heavy rainfall and ice melting season, with the increasing population and associated water usage (source). With the increasing population and associated water usage. The sewage system in Urumqi is likely to become overloaded in the near future. In addition to capacity overload issues, trash in the sewage pipelines also poses a significant problem. In 2016, 1182.2 tons of trash were cleaned out from the sewage pipeline, including various objects such as plastic bottles, stones, and wooden boards, as well as larger items such as sofas, tires, and TV shells (source). There are few applicable policies in place to address the trash problem, and it is challenging for municipalities to track down the sources. Furthermore, with the anticipated increase in water supply from melting glaciers over the next 55 years, the sewage system and wastewater treatment plants in the city are likely to face severe overburden issues in the next 50 years and beyond.

Insufficient Wastewater Treatment Pricing

The Urumqi Water Group Co., Ltd, established in 2003, is a state-owned company responsible for the unified control and management of all water resources in Urumqi. As the primary owner and operator of the water provider, the company offers water supply and waste purification services to Urumqi and the surrounding regions (source). Although most utilities companies in China are state-owned and receive government funding, the wastewater prices are not self-sustaining. In Urumqi, the wastewater fee consists of two components: the wastewater treatment charge and the piping network maintenance fee. The wastewater treatment charge is based on usage, while the piping maintenance fee is the same for all users. In the past, the wastewater price was not enough to maintain the city’s wastewater treatment system. However, in 2017, Urumqi’s water authority announced an increase in the wastewater fee. For residential wastewater, the price rose from 0.5 RMB to 0.95 RMB per cubic meter, while for non-residential use (including industrial, commercial, and others), the price increased from 0.5 to 1.4 RMB per cubic meter. The piping network maintenance fee also increased from 0.1 to 0.25 RMB per cubic meter (source). Although most utilities companies in China are state-owned and receive government funding, the wastewater prices are not self-sustaining. In Urumqi, the wastewater fee consists of two components: the wastewater treatment charge and the piping network maintenance fee. The wastewater treatment charge is based on usage, while the piping maintenance fee is the same for all users. In the past, the wastewater price was not enough to maintain the city’s wastewater treatment system. However, in 2017, Urumqi’s water authority announced an increase in the wastewater fee. For residential wastewater, the price rose from 0.5 RMB to 0.95 RMB per cubic meter, while for non-residential use (including industrial, commercial, and others), the price increased from 0.5 to 1.4 RMB per cubic meter. The piping network maintenance fee also increased from 0.1 to 0.25 RMB per cubic meter. (source)

Solutions

Among the many chanllenges Urumqi are facing, we are going to focus on glacier melting and physical scarcity issues.

Glacier Melting

Urumqi’s heavy reliance on meltwater from the Tian Shan glacier and Bogda Peak for its water supply is increasingly threatened by global warming. While there may be some short-term benefits such as increased water availability for agriculture and tourism, the melting of glaciers can also result in sudden, destructive floods that can damage the city’s infrastructure and threaten the safety of its residents.

To mitigate the potential damage caused by flooding, it is crucial to implement an early flood warning system. Such a system would enable us to monitor water levels, rainfall, and other weather-related factors that can contribute to flooding. By doing so, we can notify residents in advance and take appropriate safety measures to protect lives and property. Additionally, this system would help us manage our water supply more effectively and ensure that it is used efficiently to meet the needs of the community (source).

As the glaciers melt, the water supply will become increasingly uncertain, leading to more water shortages, reduced water quality, and higher costs for the Urumqi Water Group Co., Ltd. In addition, the loss of glaciers will negatively affect the ecosystem and biodiversity in the region, which will have far-reaching consequences for the environment and the community’s well-being. Therefore, it is critical to develop a comprehensive water management plan that accounts for the melting glaciers and includes strategies to mitigate the negative impacts on the water supply, ecosystems, and society (source).

Building reservoirs to hold the water that melts from the snow mountains is one approach to addressing this issue. Reservoirs have proven to be effective in other regions, and they can be vital in protecting Urumqi’s water supply. Besides storing water, well-designed reservoirs can also control its flow, prevent flooding, and even generate power.

Based on the topography and hydrology of the Kaidu River valley, it seems like a feasible location for a reservoir that could help mitigate Urumqi’s water scarcity problem. However, it is important to conduct a thorough environmental impact assessment before proceeding with such a project. The construction of a reservoir can have significant environmental consequences, including changes to the river’s flow, water quality, and aquatic habitats. Careful planning and management are necessary to minimize the negative impact on the local ecosystem. Additionally, the project’s economic feasibility must be evaluated, including the cost of construction, maintenance, and operation, as well as potential benefits such as increased water availability for agriculture and tourism, flood control, and power generation (source).

Physical Scarcity

With the limited existing water resources around Urumqi, it is almost impossible to address the city’s physical water scarcity issue by increasing water sources. However, a sufficient way to meet the city’s increasing water demand would be to increase the circulation rate of the existing water source. This can be achieved through three methods:

Increasing the the number of reclaimed water treatment plants
Optimization of current reclaimed water use
Improve wastewater treatment efficiency

1.Increasing the the number of reclaimed water treatment plants

The definition of reclaimed water in China refers to sewage that has gone through wastewater treatment plants and has a water quality that meets the “Water Quality Standard for Reclaimed Water.”(SL368-2006), which can be use for non-portable purpose. Previously, the municipal office has already taken reclaimed water into consideration as a solution for the city’s water supply. Currently, there are five existing reclaimed water plants that have been transformed from wastewater treatment plants. Additionally, there is one reclaimed water pipe that discharges the reclaimed water from the plants located in the south at a high elevation to a reservoir in the north at a lower elevation. (source)The introduction of the reclaimed water plants has alleviated the city’s water stress issue by using reclaimed water for industrial and landscaping purposes.(source)

Dark Brown Dot: Wastewater Treatment Plant

Dark Brown Dots: Wastewater Treatment Plants Yellow Dots: Existing Reclaimed Water Plants

With the resulting benefits, upgrading the five existing wastewater treatment plants to reclaimed water plants, as indicated in the map below, would be a viable solution. Additionally, three new reclaimed water plants can be built around canals and other waterways that connect to areas where landscape and industrial water use are needed. There could also be an expansion of pipes that transport the reclaimed water to the reservoirs and lakes nearby.

Purple Dots: Planned Reclaimed Water Plants

2. Optimization of current reclaimed water use

In the planned municipal reclaimed water project, reclaimed water will be used for green infrastructure in 12 sites around the city, including water-scape parks, wetlands, and recreational community gardens. The implementation of these green infrastructures will bring various benefits, such as beautifying the city’s landscape, treating reclaimed water through artificial wetlands, improving water quality, controlling flooding, increasing biodiversity, and restoring the ecosystem.

Planned Municipal Reclaimed Water Project Landscape Rendering

In fact, the green infrastructure project would bring many benefits as intended. However, a more optimal use of reclaimed water would be to manage it for agricultural use, as agriculture accounts for 61% of the city’s total water usage. As the population continues to grow, the increasing demand for food would further deepen the city’s water stress level. Therefore, in this situation, using reclaimed water for agriculture instead of green infrastructure would better improve the city’s water efficiency.

As shown on the map below, four major agricultural areas in Urumqi – Midong district, northern Gaoxin district, Tianshan district, and southern Urumqi county – currently rely on water supplied from the main supply line and nearby reservoirs. Among these areas, Midong district accounts for 46.6% of Urumqi’s farmland and is known for cultivating water-intensive crops such as rice. To address the water scarcity issue in these areas, more reclaimed water can be channeled and used (image below).

For the Midong district, a new reclaimed water pipeline could be constructed to transport water from Erdonggou reservoir to Shierhu Lake, which would provide easy access to reclaimed water for farmland in the district. In the northern Gaoxin district, expanding the current canal to Qinggeda Wetland would enable the reclaimed water treated at three downstream plants to reach the farmland in the district. The two agricultural areas in the southern part of Urumqi are currently facing farmland abandonment due to water scarcity. Expanding the nearby canal to Wulabo Reservoir, which is the largest reservoir in Urumqi, and building reclaimed water plants downstream would provide more water access and enable water reuse for agriculture purposes in these areas.

New Recommendation Plan

3. Improve wastewater treatment efficiency
Another way to increase the water circulation rate is by improving wastewater treatment efficiency through a water elevation piping system. In 2022, such a system was constructed in the eastern part of the city. (source) This water elevation piping system can pump reclaimed water treated from sewage in the north back to the reservoir located in the south. Originally, the city had a higher elevation in the south and a lower elevation in the north. The reclaimed water plants mostly located in the lower elevation area are likely to create a surplus of reclaimed water supply. With this elevation pipe, more sewage-turned reclaimed water can be directly used for non-portable purposes throughout the entire city. This artificial water transition would enable an increase in water circulation throughout the city.

Built Water Elevation Piping System

The proposed construction of a new elevation pipe on the western side of the city would facilitate the supply of reclaimed water from the existing plants to the northwest agricultural area. This would increase the efficiency of water usage in the city and improve the overall water circulation rate. The new pipe can be connected to the main water channel that flows from the northwest area to the reservoir in the south, enabling the direct transfer of reclaimed water for agricultural use.

Urumqi Water Solutions Map

urban water atlas

COMBAT WATER DILLEMAS IN URUMQI: STORAGE AND REUSE

Background

Challenges

Solutions

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