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While the amount of research on NBS is growing rapidly, there is a lack of evidence on community experiences of NBS design and implementation, particularly from low-income and informal settlements of African cities. This article adds new empirical evidence in this space through grounded analysis of NBS “niche” projects co-developed by intermediary organizations and communities in five sites across three settlements in Nairobi and Dar es Salaam. Findings are organized around four established NBS knowledge gaps: (1) NBS-society relations; (2) Design; (3) Implementation; (4) Effectiveness. We find that across the five studied sites, residents' perceptions and valuation of urban nature has changed through processes of co-design and co-implementation, enabling community ownership of projects, and hence playing a crucial role in NBS effectiveness over time. The integration of gray components into green infrastructure to create hybrid systems has proven necessary to meet physical constraints and communities' urgent needs such as flood mitigation. However, maintenance responsibilities and cost burdens are persisting issues that highlight the complex reality of NBS development in informal settlements. The cases highlight key considerations for actors involved in NBS development to support the replication, scaling up and institutionalization of NBS. These include the need to: (i) develop forms of engagement that align with co-production values; (ii) capture communities' own valuation of and motivations with NBS development for integration into design; (iii) elaborate technical guidance for hybrid green-gray infrastructure systems that can be constructed with communities; and (iv) help define and establish structures for maintenance responsibilities (especially governmental vs. civil society) that will enhance the environmental stewardship of public spaces.
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This content will become publicly available on March 1, 2026
Scaling Nature‐Based Solutions for Fluvial Floods: A Worldwide Systematic Review
ABSTRACT Despite increased understanding and adoption of nature‐based solutions (NBSs) within urban and coastal areas, large‐scale NBS for fluvial flood mitigation remain challenging to study and implement. A stronger evidence base is needed to identify critical research gaps and to best inform the design and deployment of NBS on the watershed scale. We synthesize evidence of the performance and co‐benefits of NBS for fluvial flood mitigation based on a systematic review of 131 peer‐reviewed papers worldwide, developing an Ecosystem Focus Type (EFT) to compare flood mitigation across large‐scale NBS. While we find that NBS can mitigate fluvial floods across all EFTs, our study also highlights that inconsistencies in measurement methods, a dearth of empirical case studies, and large variability in reported values limit generalization and comparison across NBS. Co‐benefits for fluvial flood NBS are numerous, but few are quantified, and study methods vary with regard to specific NBS. Social benefits of NBS, including benefits to communities most in need of support, are infrequently part of these studies. There is a clear need to develop common design and performance standards for large‐scale NBS and for guidance on which measures are key to consider and monitor for flood mitigation and co‐benefits. The success of large‐scale NBS for fluvial flood mitigation will depend on research and practice guided by transdisciplinary systems thinking approaches that can deliver evidence‐based, community‐driven outcomes.
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- PAR ID:
- 10617136
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- WIREs Water
- Volume:
- 12
- Issue:
- 2
- ISSN:
- 2049-1948
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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