1. General information Location and description of the intervention City or FUA Cagliari (FUA) Region Europe Native title of the NBS intervention Mitigazione del rischio idraulico Rio Mannu-Cixerri Short description of the intervention In 2020, the Metropolitan City of Cagliari launched a project to enhance flood resilience and ecological integrity in the Mannu-Cixerri river system in southern Sardinia. The river traverses several communes within the metropolitan area, ultimately feeding into the Santa Gilla Lagoon, a vital wetland ecosystem west of the city. The project, with a budget of €21 million, focuses on three key communes: Assemini, Decimomannu, and Uta. Rather than solely emphasizing structural flood defenses, the initiative integrates nature-based solutions (NbS) to mitigate flood risks while restoring riverine ecosystems. The Metropolitan City of Cagliari, in collaboration with the Sardinian Regional Public Works Department, is responsible for its implementation. Key interventions include reinforcing and revegetating embankments, improving water flow along the Rio Mannu, and constructing new levee sections in a manner that enhances natural water retention. Additionally, the project involves upgrading bridges to facilitate better floodwater management. These measures align with the Sardinian Flood Risk Management Plan (PGRA) and aim to reduce flood hazards while promoting ecological benefits. The project timeline began with a two-year preparation phase for the Preliminary Design Document, followed by a year-long tendering process for construction. These efforts represent a crucial step toward long-term flood resilience and environmental sustainability in the region. (Ref. 1, 2, 3) Website of the intervention https://www.unionesarda.it/news-sardegna/provincia-cagliari/rio-mannu-cixerri-2… Principal problems Climate-Related Hazards River flooding Extreme weather events (e.g. storms, hurricanes) Land use and Socio-economic change Economic losses due to disasters and environmental degradation Implementation area characterization Climate Temperate ( Humid subtropical, Hot-summer Mediterranean, Warm-summer Mediterranean, Warm-temperate with dry winter) Ecosystem Rivers/streams Address Cagliari Italy Location The NBS is situated in an area, with clear delineation of boundaries and a specific shape (polygon). The NBS project can also have more than one area location (more than one polygon, situated close by). Area boundary (map-based) NBS area image Source of NBS area image Source image: https://pianogestionerischioalluvioni.regione.sardegna.it/documenti/1_617_20211222120316.pdf Area description Freshwater landscape (e.g. river, lake) Type of area before implementation of the NBS Freshwater setting (e.g. river, channel, lake, pond) Timeline of intervention Start date of the intervention (planning process) 2020 Start date of intervention (implementation process) 2023 End date of the intervention ongoing Present stage of the intervention Ongoing 2. Objectives of the intervention Objectives of the intervention Goals of the intervention To reduce flood damage, particularly in areas surrounding the Santa Gilla Lagoon. To improve the response to flash floods. As climate change causes shifts in weather patterns, leading to more intense and unpredictable rainfall, the project aims to mitigate the impact of these events. To strengthen and raise existing levees, improve the water flow capacity of the Rio Mannu, and construct new sections of levees and riverbanks where necessary, and maintain existing riverbanks. These upgrades are designed to manage water levels during heavy rain and reduce the risk of overflow. To reinforce and complement the Flood Risk Management Plan of Sardinia (PGRA), a strategy that aims at mitigating flood hazards and enhancing resilience in vulnerable areas. (Refs. 1, 2, 3, 5, 6, 8 & 9). Key Priorities Climate action (adaptation and/or mitigation) Sustainability challenge(s) addressed Climate action for adaptation, resilience and mitigation (SDG 13) Climate change adaptation Green space, habitats and biodiversity (SDG 15) Green space creation and/or management Water management (SDG 6) Flood protection Stormwater and rainfall management and storage Inclusive and effective governance (SDG 16) Disaster-risk reduction Climate change adaptation: What activities are implemented to realize the conservation goals and targets? Implement measures that prevent/manage desertification, soil erosion and landslides Implement sustainable urban drainage schemes to manage stormwater Restore rivers and other fresh water bodies to reduce flood or drought risk Implementation activities and NBS focus Implementation activities The project is ongoing. In 2020, an agreement was signed between the Department of Public Works of the Sardinia Region and the Metropolitan City of Cagliari. From 2020 to 2022, the project focused on preparing the Preliminary Design Document. After consultation with regional offices, this document will be submitted for approval by the Metropolitan Mayor, paving the way for the tender procedure to begin. In 2023, the tendering process for the assignment of construction work was set to be completed. Planned activities include creating, raising, and reinforcing riverbanks and embankments, which will allow vegetation to cover and stabilize the land. The project may also involve removing certain bridges to enable natural vegetation growth. Additional activities include maintaining existing banks, constructing flood discharges, creating overflow thresholds, reorganizing flood-prone hydraulic networks near existing banks, and improving the flow capacity of the Rio Mannu. (Refs. 1, 2, 3, 5, 6, 8 & 9) Type of NBS project Creation of new green areas Creation of any other green urban spaces Management and improved protection of rivers and other blue areas River rehabilitation/ restoration Restoration, protecion and sustainable manage floodplains Restoration of riparian vegetation Ecological restoration of ecosystems Soil remediation and revegetation Strategy, plan or policy development Development of disaster-risk prevention strategies (e.g.fire management, flood alleviation scheme) 3. NBS domains, ES and scale NBS domain and interventions Ecological domain(s) where the NBS intervention(s) is/are implemented Blue infrastructure Rivers/streams/canals/estuaries Riverbank/Lakeside greens Amenities offered by the NBS Unknown Design elements for well-being None of the above Services Expected ecosystem services delivered Regulating services Flood regulation Scale Spatial scale Meso-scale: Regional, metropolitan and urban level Beneficiaries Demographics in implementation area The project is being implemented across Cagliari and its municipalities. In 2022, Cagliari had a population of 150,679. The most populous age group in the city is the 50s, with 25,764 people (17.10%), followed by those in their 60s, numbering 22,212 (14.74%). There are 78,403 families in Cagliari; of these, 49.06% are single-person households, and 25.36% consist of two people. Larger families are relatively rare, with only 2.64% of households having five or more members. Cagliari has a positive migration balance of 895 people, with 4,510 immigrants and 3,615 emigrants. There are 9,480 foreign nationals residing in the city, an increase of 253 from 2021, making up 6.29% of the total population. In 2022, the largest foreign communities were Filipino, Ukrainian, Romanian, and Chinese, collectively representing 45.30% of the foreign residents (Ref. 12) Socio-economic profile of the area Unknown Communities vulnerable to environmental hazards or climate change impacts Yes Specification of climate or environmentally vulnerable communities Riverfront communities Communities located in floodplains Non-government actors Public sector institution (e.g. school or hospital) Private sector/Corporate/Business Primary Beneficiaries Citizens or community groups Food producers and cultivators (i.e. farmers, gardeners) Specify primary beneficiaries The primary beneficiaries of the Mannu-Cixerri project are the residents and farmers located close to the river. Local residents will benefit from reduced flood risk, improving safety and protecting homes and infrastructure. Farmers, who rely on the fertile land in the area, will see reduced damage to crops and soil, safeguarding their livelihoods and experiencing fewer disruptions and infrastructure damage, promoting economic stability and growth in the region (Refs. 1, 2 & 3). Marginalized groups Vulnerable populations in disaster-prone areas Measures for inclusion of marginalised groups The project addresses the risk of floods and aims to address it from its root cause (Refs. 1, 2 & 3). Other beneficiaries Native plant vegetation Natural habitats (e.g. wetland, forests, coastal areas) City infrastructure (e.g., reduced flooding, improved water quality) 4. Governance and financing Governance Governance arrangements Co-governance with government and non-government actors Please specify the roles of the specific government and non-government actor groups involved in the initiative The Metropolitan City of Cagliari is tasked with managing and executing the project, which includes the design, planning, and coordination of the various interventions aimed at reducing flood risks in collaboration with local municipalities affected and with private actors charged with construction work or rehabilitation of the river. Overseeing the initiative is the Sardinian Regional Department of Public Works, which ensures that all activities align with regional policies and established flood risk management plans. The project is funded by CIPESS (the Interministerial Committee for Economic Planning and Sustainable Development). ( (Refs. 1, 2, 3 & 11) Key actors - initiating organization Regional government Local government/municipality Key actors - Other stakeholders involved (besides initiating actors) National government Local government/municipality Private sector/corporate actor/company Participatory methods/forms of stakeholder involvement (all stakeholders) Co-planning (e.g. stakeholder workshops, focus groups, participatory mapping) Joint implementation (e.g. tree planting) Co-management/Joint management Uncommon actors ("Missing actors") Unknown Land owners Public space owned by the city Policy drivers NBS intervention implemented in response to a Regional Directive/Strategy Yes Please specify the "Regional Directive/Strategy" The intervention is related to the regional Flood Risk Management Plan, envisaged by Directive 2007/60/EC which aims to reduce the negative consequences of floods on human health, the environment and society (Ref. 7). NBS intervention implemented in response to a national regulations/strategy/plan Yes Please specify the national regulations/strategy/plan Legislative Decree 49/2010, which aims to reduce the negative consequences of floods on human health, the environment and society (Ref. 7). If there is a relevant strategy or plan, please specify the theme/type of the plan National Disaster Risk Reduction Plans NBS intervention implemented in response to a local regulation/strategy/plan Yes Please specify the "local regulation/strategy/plan" Il Piano di Gestione del Rischio Alluvioni della Sardegna (PGRA) (1) Relevant strategy or plan Other Please specify other local relevant strategy Risk reduction strategy (1) Mandatory or voluntary intervention Mandatory (based on policy) Intervention is mandatory Other Please specify other type of mandatory intervention Disaster risk regulation (1) Enablers & Barriers Type of enablers Change agents (individual with major role influence on launching) City network or regional partnerships focused on climate change, sustainability, GI or NBS in the city Funds, subsidies or investment for GI/NBS in the city (available for the city or provided by the city) Please provide details (e.g, name of the plan or strategy) for the selected policies or initiatives. 1.The councilor for Roads, Mobility, and Waterways, Antonello Floris, is a key figure in the project, highlighting the importance of mitigating hydraulic risk and ensuring that the project moves forward efficiently (Refs. 1, 2 & 3). 2. The intervention extends on many municipalities, as the river goes through all of them, which are collaborating for the planning process (Refs. 1, 2 & 3). 3. The funds come from the government which allocated them through the Interministerial Committee for Economic Planning and Sustainable Development (CIPESS), which is responsible for the public investment policies oriented towards the pursuit of sustainability objectives (Ref. 11) 4. Private actors charged with construction work or rehabilitation of the river. (Ref. 11) Governace and decison-making instruments Legislative and regulatory instruments (e.g. laws, strategies, regulations or restrictions) Strategic instruments (e.g. GI strategies, green space strategy or plans) Joint regional planning between municipalities (e.g. inter-municipal exchange platforms, regional plans for environmental management) Economic and fiscal instruments (e.g. subsidies or grants, charges or fees, payments for ecosystem services (PES)) Public - private business agreement (e.g. public private collaborations, public-private-partnerships (PPP)) Arrangements for governance cooperation Information-sharing platforms or networks (e.g. websites for sharing best practices, data or resources pertinent to the project) Barriers unknown Financing Total cost More than €4,000,000 Please specify total cost (EUR) € 21,000,000 (Refs. 1, 2, 3 & 4) What is/was the Cost/Budget (EUR) of the NBS or green infrastructure elements? n/a Source(s) of funding Public national budget Type of fund(s) used Direct funding (grants, subsidies, or self-financed projects by private entities) Non-financial contribution Unknown Co-finance for NBS No Entrepreneurship opportunities No Business models Business models Risk reduction model Which of the involved actors was motivated by this model? Public actor (e.g. municipality) 5. Evaluation and learning Impacts, benefits Environmental impacts Climate change Strengthened capacity to address climate hazards/natural disasters Expected strengthened capacity to address climate hazards/natural disasters Environmental quality Improved stability of slopes Expected improved stability of slopes Water management and blue areas Increased protection against flooding Expected increased protection against flooding Description of environmental benefits - Strengthened capacity to address climate hazards/natural disasters: "will include interventions for the reinforcement and raising of the banks, the improvement of the flow capacity of the Rio Mannu, the construction of sections of new banks and work on some bridges." (Ref. 2) - Improved stability of slopes: "will include work to reinforce and raise the embankments" (Ref. 1) - Increased protection against flooding: "The sum allocated does not have as its objective the securing pursued by the AMP, but rather the mitigation of hydraulic risk, i.e. the reduction of flood damage" (Ref. 1) Economic impacts Unknown Description of economic benefits unknown Social and cultural impacts Safety Improved community safety to climate-related hazards Expected improved community safety to climate-related hazards Description of social and cultural benefits - Improved community safety to climate-related hazards: "The intervention is part of those planned by the C.B.S.M. aimed at protecting the built-up area of Uta from flooding of the extra-urban drainage network from the terminal sections of the Fluminimannu and Cixerri rivers, which have already caused serious damage in the past." (Ref. 11) Evidence for use of assessment Presence of an assessment, evaluation and/or monitoring process Yes Actors involved in the assessment, monitoring or evaluation of NBS impacts Local government/municipality Presence of indicators used in reporting Yes Type of indicators Process indicators Progress indicators Presence of monitoring/evaluation reports No evidence in public records Availability of a web-based monitoring tool No evidence in public records Name of any specific impact assessment tools unknown Link to the output of assessments https://www.regione.sardegna.it/atti-bandi-archivi/atti-amministrativi/tutti-gl… Use of GIS in mapping impacts No evidence in public records Cost-benefit analysis Yes Transparency Public disclosure of project funding sources and/or budgets Online disclosure of technical reports (e.g. project documents, reports, or data) Justice Community satisfaction Unknown Description of locals satisfaction with the project unknown Trade-offs & Negative impacts Unknown Emphasis of existing social inequalities or injustices No information reported related to negative social justice-related impacts of the NBS project Measures to prevent gentrification or displacement No initiatives or policies were implemented High-quality & Transformative NBS Multiple impacts delivery (climate, biodiversity, just community) No Goal setting and impacts delivery No, project goals were not set, and benefits were not delivered in all 3 key areas. Reaching original project goals Inconclusive as the project is still undergoing implementation, or is still on its planning stages Please specify the achievements of the project goals The project is currently in the implementation stage, but there are no available sources indicating the progress of this process. Long-term perspective Yes Cost-effective solutions Yes Equitable impacts A. All stakeholders benefit fairly from the project Transformative capacity Technical change (e.g. built infrastructure of cities and their parts, roads, buildings and so on) Magnitude of change Reformist: by focusing on addressing underlying drivers of change but failing to address the problem structurally or systemically Application of lessons learned The NBS has informed policy and regulatory processes Perception of Environmental Change Unknown 6. Sources References 1. L'Unione Sarda (2020). Rio Mannu-Cixerri, 21 milioni per la mitigazione del rischio idraulico. Accessed on September 12, 2024, [Source link] [Archive]; 2. Cagliari Post (2020). Rio Mannu-Cixerri, al via progetto per la mitigazione del rischio idraulico. Accessed on September 12, 2024, [Source link] [Archive]; 3. Casteddu Online (2020). Rio Mannu-Cixerri, al via progetto da 21 milioni di euro per la mitigazione del rischio idraulico. Cagliari: Casteddu Online, Accessed on September 12, 2024, [Source link] [Archive]; 4. Regione Autonoma della Sardegna (2020). Ordinanza Commissario di Governo N.55 protocollo n. 1096 del 27/05/2020. Accessed on September 12, 2024, [Source link] [Archive]; 5. Regione Autonoma della Sardegna (n.d.). Normativa. Accessed on September 12, 2024, [Source link] [Archive]; 6. Regione Autonoma della Sardegna (2021). Piano di gestione del rischio di alluvioni . Accessed on September 12, 2024, [Source link] [Archive]; 7. Giunta regionale Sardegna (2020). RISCHIO IDROGEOLOGICO, SOLINAS: OLTRE 160 INTERVENTI FINANZIATI. AL VIA LA PROGETTAZIONE DELLE OPERE SUL RIO MANNU-CIXERRI PER 21 MILIONI. Accessed on September 12, 2024, [Source link] [Archive]; 8. Regione Autonoma della Sardegna (2021). Scenari di intervento strategico e coordinato: Rio Cixerri . Accessed on September 12, 2024, [Source link] [Archive]; 9. Regione Autonoma della Sardegna (2021). Scenari di intervento strategico e coordinato: Flumini Mannu . Accessed on September 12, 2024, [Source link] [Archive]; 10. Regione Autonoma della Sardegna (2023). MANUTENZIONE DEGLI ALVEI NATURALI E CANALIZZATI PRESSO LE SEZIONI IDROMETRICHE DELLA RETE DI MONITORAGGIO METEOROLOGICO E IDROPLUVIOMETRICO DELLA REGIONE SARDEGNA . Accessed on September 12, 2024, [Source link] [Archive]; 11. Dipartimento per la programmazione e il coordinamento della politica economica (n.d.). Il Comitato interministeriale per la programmazione economica e lo sviluppo sostenibile. Accessed on September 12, 2024, [Source link] [Archive]; 12. Comune di Cagliari 2022 (2022). Atlante Demografico di Cagliari 2022. Accessed on September 12, 2024, [Source link] [Archive]; Comments and notes Public Images Image vegetation-takes-over https://pianogestionerischioalluvioni.regione.sardegna.it/documenti/1_617_20211222120316.pdf Image embankment https://pianogestionerischioalluvioni.regione.sardegna.it/documenti/1_617_20211222120316.pdf Image aerial-view https://pianogestionerischioalluvioni.regione.sardegna.it/documenti/1_617_20211222120316.pdf
Image vegetation-takes-over https://pianogestionerischioalluvioni.regione.sardegna.it/documenti/1_617_20211222120316.pdf
Image embankment https://pianogestionerischioalluvioni.regione.sardegna.it/documenti/1_617_20211222120316.pdf
Image aerial-view https://pianogestionerischioalluvioni.regione.sardegna.it/documenti/1_617_20211222120316.pdf
