Evaluation of Tajrish neighborhood based on indicators of water sensitive cities

Introduction: Cities are currently facing significant challenges. Urban life has been profoundly impacted by climate change. The rise in the Earth's average temperature is a key factor driving the increased frequency and intensity of extreme weather events such as floods and droughts, which directly affect the lives and well-being of millions of people and the environment. Additionally, cities are rapidly expanding, consuming land and water in surrounding areas, often at the expense of agricultural lands. Many cities around the world suffer from inadequate infrastructure and unequal access to essential services, which disproportionately affect vulnerable groups. Urbanization and growing competition among different land uses and economic sectors are making water an increasingly scarce resource. Climate change further exacerbates these pressures by heightening the risk of floods, droughts, and heatwaves. These challenges demand a systemic approach and a shift in urban planning and water management. Traditional urban water management systems provided services such as water supply, wastewater management, drainage, and flood control. However, urban water management is now increasingly integrated with broader goals of livability and sustainability. In recent decades, several countries have developed new approaches to urban water management. These approaches all embrace sustainable development as a core objective, with the concept of Water Sensitive Cities emerging as a notable model. This concept is linked to a new paradigm in urban water management that advocates for the use of decentralized water systems. Since the introduction of practical water-sensitive indicators, substantial efforts have been made to implement them in cities with diverse social, organizational, and biophysical conditions worldwide Iran is not exempt from this crisis, and its water resources are far from ideal. Situated in the arid and semi-arid belt of the world, Iran is considered one of the countries with limited water resources. Its share of the world’s fresh water is relatively low compared to other regions. With Iran’s growing population, the annual per capita renewable water resources decreased to about 800 cubic meters in 2021, below the water scarcity threshold of 1,000 cubic meters. The decline in groundwater resources is a clear sign of unsustainable management and national water bankruptcy. At the current rate of exploitation, 12 out of 31 provinces in Iran will completely deplete their groundwater reserves within the next 50 years. Tehran, the capital, faces one of the most critical water resource conditions. Factors such as population growth, urbanization, green spaces, industries, unsustainable water consumption, lack of rainfall, and evaporation contribute to water loss in the Tehran area. Tehran Province, which accounts for more than 20% of the country's population, occupies less than 1% of its land area. It is evident that providing water for this dense population is a challenging task. Over the past two years, Tehran has been recognized as the country’s highest water-consuming city. The city of Tehran comprises 22 districts and 376 neighborhoods, each differing in physical, environmental, and cultural aspects. One of Tehran’s neighborhoods, Tajrish in District 1, has been particularly notable because of its
historical significance and location. This neighborhood is noteworthy in terms of water management because it has numerous active Qanats. Additionally, the presence of the Darband River Valley is one of its unique features. A review of Iran’s flood history shows that one of the most destructive floods occurred in this neighborhood, highlighting the need for measures to achieve sustainable water resource conditions. This study aims to evaluate the Tajrish neighborhood based on Water Sensitive Cities (WSC) indicators and to answer the question of how Tajrish stands in terms of WSC criteria. It also seeks to provide solutions for achieving water sustainability in Tehran. Implementing the necessary measures to become a Water Sensitive City can help reduce costs and foster a sustainable and socially committed approach to urban water resource management.
Methodology: This research is an applied study aimed at assessing the status of the Tajrish neighborhood based on the indicators of Water Sensitive Cities. To achieve this objective, we employed multiple methods for data collection and analysis, which are detailed below:
In the first phase, we gathered information using library and documentary methods, which included documentary studies, library research, and a thorough review of the literature. In the next step, we used a questionnaire to collect information for assessing the status of the Tajrish neighborhood in relation to a Water Sensitive City, utilizing the Likert scale. These questionnaires were distributed among 30 water and urban planning experts and reached theoretical saturation. After distributing the questionnaires among the experts and scoring each criterion and sub-criterion, we used the one-sample t-test in SPSS software to determine the status of each of these criteria and sub-criteria in this neighborhood relative to a Water Sensitive City. Subsequently, we categorized these criteria into five ranges, from very weak to very good.
Results: To identify the most significant deficiencies among the main components and sub-criteria, we use a classification method. In the t-test, we considered the highest level, representing a Water Sensitive City, as one, and we ranked the criteria into five groups within the range of zero to one. According to experts, Tehran has the smallest gap regarding equity and equality compared to Water Sensitive Cities, while the worst situation pertains to efficiency and performance. By examining each criterion and sub-criterion based on their importance in the Tajrish neighborhood, we found that most indicators fall within the range of 0-0.2, which is weak, and 0.21-0.4, which indicates moderate conditions. Only three sub-criteria—equitable access to safe and reliable water resources, equitable access to a safe and reliable sewage network, and vegetation cover—were classified as good.
Conclusion: Population growth and the lack of consideration for water elements in urban planning have resulted in significant challenges for today's cities regarding water resource availability, impacting their sustainability. It is evident that traditional urban water management models are insufficient, and modern cities require the adoption of new approaches for urban water management. The Water Sensitive Cities model, which has emerged in the past two decades, represents a novel approach to urban water management, advocating for the use of decentralized water systems. This model aims to maximize opportunities for better living conditions and efficient resource utilization, including the reuse and management of water and wastewater, to promote and support human health while minimizing the impacts of urbanization on the natural environment and the water cycle. In this study, we assessed the status of the Tajrish neighborhood based on the indicators of Water Sensitive Cities using the one-sample t-test. The results indicated that Tajrish predominantly falls within the weak and moderate categories for these indicators. Only three sub-criteria—equitable access to safe and reliable water resources, equitable access to a safe and reliable sewage network, and vegetation cover—were classified as good. Consequently, Tajrish requires long-term planning across all dimensions and strategies ranging from micro to macro levels.