Introduction
Accelerating climate change, and particularly the rise of hydrological hazards such as flooding, sea-level rise and erosion, has intensified interest in nature-based solutions (NbS) as approaches that can simultaneously address climate adaptation, biodiversity loss and human wellbeing. In many regions, these hazards intersect with Indigenous territories where long-standing relationships to land and water, and rich Indigenous knowledge systems, shape both vulnerability and capacity to adapt. While international and national policy frameworks increasingly reference NbS and Indigenous knowledge, it remains unclear how, in practice, different knowledge systems are brought together in NbS projects, and with what implications for justice. This paper presents a systematic review of NbS that involve Indigenous communities, with a particular focus on hydrological risks, to examine: (1) how such NbS are conceptualised and in which ecosystem contexts and hazard types they are implemented; (2) through which governance models, participatory methods and epistemic frameworks bridging between scientific and Indigenous knowledge is operationalised; and (3) what kinds of benefits, tensions and gaps emerge from the perspective of epistemic, procedural and distributive justice.
Methodology
The study adopts a systematic review design, combining elements of environmental evidence synthesis and qualitative meta-synthesis. A structured search was conducted across major academic databases and selected grey-literature sources, using combinations of keywords related to nature-based solutions, Indigenous or tribal communities, climate adaptation and water- or flood-related hazards. Inclusion criteria targeted empirical studies and policy-oriented reports that: (a) explicitly framed actions as NbS or closely related concepts (e.g. ecosystem-based adaptation, natural climate solutions); (b) involved Indigenous communities as knowledge-holders, partners or rightsholders, rather than generic “local populations”; and (c) addressed climate-related risks, with particular attention to hydrological impacts.
After screening titles, abstracts and full texts, the final corpus was coded using a mixed deductive–inductive scheme. Deductive codes captured NbS types, ecosystem and hazard context, governance and leadership models, and three justice dimensions (epistemic, procedural, distributive). Inductive coding allowed emergent themes around power relations, land tenure, funding architectures and critiques of “knowledge integration” to be captured. The coded material was then synthesised thematically and interpreted in dialogue with existing theoretical debates on NbS, Indigenous knowledge and climate justice.
Results and discussion
Across the corpus, NbS involving Indigenous communities spanned a wide spectrum of interventions: restoration and protection of riparian zones, floodplains, wetlands and salt marshes; forest conservation, improved forest management and peatland protection; grassland and fire stewardship; and green infrastructure such as community gardens and nature-based coastal defences. These were implemented in coastal, riverine, forest and northern cryospheric systems, mostly in settler-colonial states of the Global North. In contrast to technocratic NbS narratives that centre cost-effectiveness and ecosystem services, the reviewed cases consistently framed NbS as part of broader processes of biocultural restoration, land and water stewardship, and the continuation or renewal of Indigenous relationships to place.
Regarding knowledge bridging, four broad models emerged: Indigenous-led NbS, co-governed or co-managed NbS, NGO-driven projects with Indigenous participation, and state-led initiatives with varying degrees of consultation. Methods and tools included participatory workshops and talking circles, participatory mapping, land-based and seasonal approaches, scenario planning, and more formal frameworks such as community-based participatory research and Two-Eyed Seeing. Where Indigenous institutions held leadership and principles such as ownership and control of data were respected, these processes supported substantive co-production of knowledge and strengthened community agency. Conversely, state-led or consultancy-driven projects often reduced participation to tokenistic consultation and treated Indigenous knowledge as an auxiliary “data source” to be translated into pre-existing scientific or policy frames.
From a justice perspective, NbS generated both enabling and constraining outcomes. Positively, some initiatives enhanced epistemic justice by recognising Indigenous knowledge as a valid and necessary basis for monitoring, planning and evaluation, and by embedding Indigenous worldviews and languages into tools and indicators. Procedurally, co-governance arrangements, Indigenous guardianship programmes and community-designed adaptation plans broadened spaces of decision-making and supported intergenerational knowledge transmission. Distributively, NbS occasionally improved access to livelihoods, employment and funding, particularly where rights to fisheries or conservation revenues were reconfigured in favour of Indigenous communities.
However, pervasive power imbalances, insecure land tenure, short-term and conditional funding and dominant legal–scientific standards often undermined these gains. Critiques of “green colonialism” and “carbon colonialism” were evident where NbS frameworks were used to justify new forms of land control or offsetting without meaningful Indigenous leadership. Several studies questioned the very language of “knowledge integration”, warning that, without decolonial governance and financing arrangements, it can entrench the primacy of Western science and instrumentalise Indigenous knowledge.
Conclusion
The review shows that NbS involving Indigenous communities are not inherently just or unjust; their outcomes hinge on who defines the problem, who leads, whose knowledge counts and how benefits and burdens are distributed. To move beyond symbolic inclusion, NbS must be re-designed as Indigenous-led and justice-centred processes that treat Indigenous knowledge systems as co-equal, uphold land and water rights, and embed long-term, flexible funding mechanisms. Future research should expand beyond the current geographic concentration, address intersectional inequalities within Indigenous communities and co-develop evaluation frameworks that reflect Indigenous values and visions of a good life in a changing climate.