Izmir has a surface area of 12.019 km2, a population of 4.4 million inhabitants, and lies in the western part of Turkey. As a well-known and fast-growing port city in the Eastern Mediterranean, the population of Izmir is predominately urban, with 91% of inhabitants residing in urban areas and the remaining 9% in rural zones.

The project area, the Peynircioglu Stream, is located in the Mavisehir neighbourhood, at the starting point of the old Gediz River Delta,  a wetland site designated to be of international importance under the Ramsar Convention and recognised as being of significant value not only for the country or the countries in which they are located, but for humanity as a whole. Although Gediz Delta has Ramsar Wetland protection status, it is adversely affected by pressures of rapid urbanisation, which has left the surrounding urban population vulnerable to extreme flooding.

The Gediz Delta plays a vital role for the city. It features a unique variety of biodiversity, diverse ecosystems and natural habitats, and significantly contributes to the city’s efforts to combat CO2 emissions. Thus, it has been nominated for inclusion on the UNESCO Natural World Heritage List. Accordingly, the tributary of Peynircioglu Stream is being managed through a series of NbS. 

In the pre-implementation phase of the project, a nature-based solutions (NbS) design workshop was organized in collaboration with various design institutions and associations. This workshop, hosted by the Izmir Metropolitan Municipality (IMM) at Fablab İzmir, was attended by approximately 70 design students and workshop coordinators. One notable outcome of the workshop, a pollinator house, was subsequently implemented in the project area. Additionally, the contributions of residents were integrated into the project during the implementation process, facilitated through the involvement of neighbourhood managers.

The project brought together key stakeholders to undertake the restoration of 1.6 km of the stream bed. During the project implementation, permeable stream bed restoration for flood management, permeable concrete applications for stormwater management, and various green space expansion and enhancement initiatives were carried out. Through the implementation of NbS, IMM focused on measures related to coastal flood and flood management on the banks of the Peynircioglu Stream. Tree cover and permeable surfaces have been greatly increased and the intensive use of pollinator-friendly plants has curbed the loss of urban biodiversity.

The project has formed the basis for many other practices and strategies applying NbS. For instance, the plants selected for the project have been incorporated into the "Natural Green Project", which is intended to restore the city's natural vegetation in its parks using local plant species. The aim is to foster a citywide approach to landscaping that prioritizes plants with lower water requirements and high adaptability. Moreover, the project's permeability capacity and green infrastructure were assessed as part of the "Sponge City Program", a scheme designed to enhance the permeability of rainwater in heavily urbanized areas.

The project also blazed a trail for the city’s “Living in Harmony with Nature” Strategy, which positions Izmir to actively combat the climate crisis, develop into a city where nature and people live in harmony, and focus on "creating partnerships for the administration of urban and rural areas across physical, economic, and cultural plans." This approach seeks to merge the concepts of urban and rural landscapes, instead of viewing them as separate entities, thereby uniting nature and culture within the flow of life.

The  Peynircioglu Ecological Restoration Project in Mavisehir district was realized by the Izmir Metropolitan Municipality (IMM) as the lead agency, utilizing both its own budget and co-financing from the European Union under the HORIZON 2020 framework. Local project partners included universities (Izmir Institute of Technology and Ege University) and SMEs (Demir Energy, and Bitnet). Throughout the project’s implementation, many different professionals had the opportunity to collaborate. For example, environmental engineers, mechanical engineers, landscape architects, computer engineers, architects, civil engineers, electrical engineers, agricultural engineers and city planners all came together to bring the project to life.

The results of the extensive use of pollinator-attracting plants within the redeveloped and expanded green spaces in and around the Peynircioglu Stream, as well as the effect of pollinator houses, were carefully observed and quantified during a two-year monitoring period. Baseline values, recorded before and after the enhancements, revealed a notable increase in the number of birds and pollinators within the newly planted areas and the expanded green spaces. This level of biodiversity was previously unseen in the area.

Similarly, trees within these green areas also had their baseline pollutant and carbon absorption rates measured before the implementation of the project and were subsequently monitored throughout the two-year period. The monitoring of the newly planted trees revealed a significant decrease in the amount of carbon present and a marked reduction in the urban heat island effect. Furthermore, the project area demonstrated high permeability in conducted tests. Interestingly, despite a flood disaster in the region in 2020, which caused houses and cars nearby to be inundated, the project area was found to be free of puddles.

In an effort to enrich biodiversity, the green spaces in the project area were populated with native, pollinator-attracting plants. Approximately 1,200 trees and 30,000 carbon sequestrant plants were planted along the 1.6 km Peynircioglu Stream Ecological Corridor.

Izmir is a fast-growing city and grapples with environmental threats such as air pollution, heat island effect, heavy traffic, and loss of natural areas. The project is located in a highly urbanized area where the heat island effect is particularly intense and harmful. The region’s topography, being predominately below sea level, poses additional risks. Storms and waves have been known to breach coastal structures and cause coastal flooding during extreme rainfall periods. 

The project encompasses a learning network for knowledge exchange between five "follower-cities" that are developing their own NbS strategies. Several workshops, ideally scheduled alongside consortium meetings, are key elements of this process. These day-long events feature representatives from Izmir Municipality sharing best practices and insights gained from their experience with the planning and implementation of urban NbS. Interspersed between these workshops, additional virtual sessions will be held. Designed to include representatives from all five participating cities, these sessions are facilitated to address any queries, enable discussions around suggestions and concerns, and promote deeper understanding of the subject matter.

Moreover, a dedicated platform will be put into place to facilitate ongoing communication between the selected representatives. This will ensure a readily available resource for exchanging ideas, posing questions, gaining insights, and ultimately supporting the follower cities throughout the process.

Additionally, the project lays the groundwork for the formation of a larger, international cluster. This cluster, which will include the follower cities, aims to be a global leader in advocating for NbS in urban planning, thereby contributing to the project's international dimension. The ultimate goal of the cluster is to promote the replication of these NbS on a global scale.