Beyond the Flow: The Many Facets of Gazelle Valley Park (Jerusalem), an Urban Nature-Based Solution for Flood Mitigation in a Mediterranean Climate

Rapid urban expansion and increasing population density intensify the loss of open spaces, exacerbate flooding frequency and runoff pollution, increase the urban heat island effect, and deteriorate ecological resilience and human well-being. This study presents Gazelle Valley Park (GVP) in Jerusalem (Israel), a unique large-scale ecohydrological infrastructure within a dense Mediterranean city. GVP was established in 2015 following a public-led campaign and comprises a multifunctional nature-based solution designed to collect and circulate stormwater through a series of vegetated ponds, enhancing filtration, aeration, and pollutant removal, while sustaining a wetland ecosystem. Its design follows international ecological standards and embodies the principle “from nuisance to resource”, transforming urban runoff into an asset that supports rich biodiversity while offering recreational, cultural, and educational activities. During the dry summer, reclaimed wastewater is introduced in order to support a perennial aquatic habitat, which introduces various challenges due to increased salinity, oxygen demand, and contaminants. Hydrometric and geochemical monitoring demonstrates strong correlations between rainfall and runoff and point at the role of sedimentation and vegetation in reducing pollutant loads. The park benefits from its holistic operation, where hydrology, ecology, education, and public engagement are integrated, thus making the whole greater than the sum of its parts.