What happened
Following flooding in Istanbul, Özay Yerlikaya, president of the Chamber of Landscape Architects of the Union of Chambers of Turkish Engineers and Architects (TMMOB), called for blue-green infrastructure to become a required part of urban planning.
In comments reported by İklim Haber, Yerlikaya said flood risk cannot be attributed solely to the intensity of rainfall. He identified unplanned urbanisation, construction in stream corridors, the loss of flood storage areas and expanding impermeable surfaces as factors that increase cities’ vulnerability.
Concrete and asphalt limit infiltration and speed surface runoff, he said. The chamber’s proposed response is an integrated blue-green approach combining water routes, open land and planted features to hold and slow rain close to its point of fall.
Yerlikaya cited rain gardens, vegetated collection and conveyance channels, permeable surfaces and wetlands as measures that can support local water retention. Under suitable conditions, these systems can also contribute to groundwater recharge.
Why it matters
The intervention puts land-use decisions at the centre of urban flood resilience. It suggests that planning authorities, developers and infrastructure teams should assess whether projects obstruct natural drainage, reduce areas available for water storage or add sealed ground cover.
Yerlikaya said conventional engineering measures may not be enough on their own as the climate crisis intensifies extreme weather. He argued that nature-based solutions should be developed alongside infrastructure investments, rather than being treated as isolated landscaping works.
The chamber also described parks, urban forests, wetlands and ecological corridors as infrastructure with practical roles in reducing flood impacts, moderating urban microclimates and supporting ecological processes. Their value, it said, extends beyond leisure and recreation.
What planners should consider next
Yerlikaya called for development to be removed from stream beds, valleys and floodplains so these areas can resume their natural functions. He also urged planning frameworks to establish connected ecological corridors.
For sustainability and resilience teams, the call points to the need for catchment-to-street-scale planning: identify drainage pathways and retention land, protect or restore them, and connect blue-green measures across sites. Yerlikaya also said landscape architects should participate actively in climate-adaptation policy, action plans and delivery.
