Preservation and expansion of green spaces in the context of acute water shortage

The rapid growth of urbanization, global warming, and climate change emphasize the urgent need to expand green spaces in urban areas. According to the World Bank, 56% of the global population currently lives in cities, and estimates show that this percentage will increase to 70–80% by 2050. In other words, 7 out of 10 people will live in urban areas. In this context, extreme weather events and recent devastating floods have further highlighted these challenges.

Green spaces play a vital role in regulating urban temperatures, filtering air pollutants, and creating a healthy habitat for the population. According to the directives of the European Union and the recommendations of the World Health Organization, cities should provide a minimum of 26 square meters of green space per inhabitant—a requirement considered essential for maintaining a balanced urban environment. However, Bucharest, like many other cities in Romania, is far below this threshold. Currently, the available green area per capita in the capital is estimated at only 9–10 square meters, significantly below European standards.

This lack of green areas in major cities generates numerous negative effects. Among them are the intensification of the urban heat island effect, which leads to significantly higher temperatures compared to rural or heavily vegetated regions. Air quality also worsens due to high concentrations of carbon dioxide and other harmful particles. Furthermore, limited access to green spaces and the lack of outdoor recreation opportunities negatively affect both the physical and mental well-being of residents.

To improve urban quality of life and align cities with European standards, it is essential to significantly expand green areas in the coming years. Achieving this goal requires substantial investments and a well-planned urban development strategy, but the positive impact on community health and well-being fully justifies these efforts.

Maintaining green spaces in optimal condition—both aesthetically and ecologically—poses a major challenge for local administrations, putting pressure on available water resources. In Bucharest, irrigating public green spaces plays an important role in managing the urban environment. According to the Bucharest City Hall, approximately 2 million cubic meters of water were used in 2022 for watering parks and public gardens.

Climate change has considerably complicated water resource management, especially for irrigation. The increasing frequency of extreme weather events, including prolonged droughts, requires efficient and responsible management of available water sources. This issue is equally relevant for urban green areas, where water requirements for irrigation can be considerable.

To conserve water resources, many European cities have imposed restrictions on green space irrigation. Countries such as Spain, Portugal, France, and Germany have introduced strict regulations to manage water consumption during drought periods.

In this context, the pressure on urban development strategies is growing, and it is necessary to identify innovative solutions to optimize green infrastructure. These solutions must not only reduce water consumption but also support biodiversity and minimize environmental impact. Sustainable measures that can be implemented include the use of smart irrigation systems, rainwater collection and reuse, and the selection of drought-resistant plant species that require less water. By applying such practices, cities can more effectively manage the challenges brought about by accelerated urbanization.

Expanding green spaces represents an effective solution to this issue, as vegetation acts as a natural sponge, absorbing significant amounts of water after heavy rainfall. Thus, green infrastructure helps prevent sewage system overload and reduces the risk of urban flooding.

In this context, landscaping can no longer be viewed solely from an aesthetic perspective; green spaces play a crucial role in improving the urban environment. They help regulate temperatures through evapotranspiration, improve air quality by capturing pollutants, produce oxygen, provide thermal and sound insulation, support biodiversity, and make cities friendlier and healthier places to live.

Urban landscaping should go beyond aesthetic concerns and also address ecological challenges, promote sustainability and biodiversity, and maximize the benefits to the urban ecosystem. The decreasing availability of water resources and the effects of climate change call for more efficient water management, leading to increasingly strict irrigation restrictions. These constraints stimulate the search for innovative solutions that provide optimal results with minimal investment in green infrastructure.

Maintaining grass-covered surfaces is a water-intensive process, especially during dry periods, when large quantities of water are required to keep them in good condition. Even with modern irrigation systems, frequent watering results in significant resource consumption. According to SNiP (Technical and Sanitary Regulations), one square meter of grass requires between 15 and 20 liters of water per irrigation, ideally one to two times per week. For compact soils, this amount can increase to 25 liters per square meter. Moreover, maintenance activities such as regular mowing, weed control, and fertilization involve substantial financial and energy costs.

To optimize resource consumption, urban greening strategies should include drought-resistant, low-maintenance plant species wherever functional requirements allow (for example, in decorative areas not exposed to daily foot traffic).

A relevant example of a resilient plant is Sedum, a species from the succulent family capable of storing large amounts of water in its leaves, allowing it to tolerate extreme weather conditions. A Sedum vegetation layer provides about 95% coverage immediately after planting, with strong roots and excellent adaptability to polluted urban environments. Additionally, these plants actively improve air quality by producing oxygen (a 500 m² Sedum area can generate the daily oxygen needed for one person) and filtering pollutants and CO₂ from the atmosphere (one square meter of Sedum can capture 0.4–2 kg of harmful substances annually).

One of Sedum’s main advantages is its ability to survive without irrigation, making it an ideal solution for conserving water resources in urban environments. These plants can endure the hot summer months without watering, adapting by turning their leaves reddish during drought and returning to green once autumn rains arrive. Thus, Sedum vegetation represents an ecological and efficient alternative for expanding urban green spaces with minimal resource use.

For tramway greening, a system similar to green roofs can be implemented, using special layers with high water retention capacity to maintain optimal moisture for plants. Such solutions enable the use of rainwater, reducing pressure on sewage systems while improving the city’s visual appeal. By integrating vegetation along tramlines and railways, cities can become more environmentally friendly, creating a more balanced and visually pleasant urban landscape.

An ecological and sustainable alternative is the use of drought-tolerant shrubs and perennial plants that can cover the soil without intensive care. Species such as rosemary, Cotoneaster, or various combinations of native perennial wildflowers can provide durable and aesthetic green areas that require neither frequent watering nor regular mowing.

Many cities worldwide have successfully implemented vegetation-based solutions adapted to harsh climatic conditions, including:

• Vienna: Implemented green roof projects using Sedum and other drought-tolerant species, contributing to water retention and reducing the urban heat island effect.
• San Diego: Uses an advanced stormwater management strategy incorporating drought-tolerant plants to control runoff and improve water quality.
• Singapore: Known for its innovative water management solutions, the city has developed technologies for water recycling and efficient irrigation, integrating climate-adapted vegetation into urban design projects.

The sustainability of urban green spaces depends on the use of low-maintenance plant species, the optimization of water consumption, and the application of modern landscaping strategies. Selecting plants such as Sedum and other xerophytic species enables the creation of green areas that not only reduce pressure on natural resources but also support biodiversity and improve urban quality of life. Through such initiatives, cities can become more environmentally friendly, more attractive, and more resilient in the face of climate change and water management challenges.