Cleaner Water, Stronger Communities: Restoring Maspalomas Pond with Nature-Based Solutions

Unlike conventional drainage systems that move water away as quickly as possible, SUDS are designed to work with natural processes. By slowing runoff, increasing infiltration, and filtering pollutants, they reduce pressure on drainage networks while creating healthier conditions for ecosystems.

In Maspalomas, the intervention is supported by a network of monitoring sensors and advanced hydrological models that track water quality and stormwater dynamics. This evidence base helps local authorities understand how the system performs over time and identify opportunities for future expansion.

Rainfall & Combined Sewer Overflow (CSO) → Filter Trench → Bioretention System → Purified Discharge to Maspalomas Pond.

Restoring the pond is not only a technical challenge but also a governance challenge. Maspalomas brings together residents, tourists, businesses, and multiple layers of government, all with different interests and responsibilities. To build consensus around the intervention, a series of events (Transformation Labs) created a space where public authorities, researchers, environmental organisations, schools, neighbourhood groups and representatives from the tourism sector could develop a common vision for the area.

A central ambition was to ensure that the economic ecosystem linked to tourism comes to see Nature-Based Solutions (NΒS) as a genuine option for enhancing destination quality, promoting processes such as the ecological enhancement of the Maspalomas pond and the widespread adoption of Sustainable Urban Drainage Systems in surrounding areas that are currently deficient in stormwater management infrastructure. The collaborative approach also highlighted the importance of long-term governance arrangements capable of coordinating action across municipal, island and regional administrations.

A complete report of the activities and results obtained can be found in test link

The NATALIE project combined monitoring and modelling to assess the NBS’s technical performance and its environmental, social, and economic benefits. Results show that nature-based infrastructure can match or outperform concrete culverts while improving water quality and reducing pollutant loads.

The SUDS treats a mixture of water from Combined Sewer Overflows (CSOs) and surface runoff from Oceanía Street. Monitoring is used to assess the total suspended solids (TSS), organic matter (BOD and COD), nutrients, and heavy metals removed by the bioretention system. Pollutant removal efficiencies are compared with reference values reported in the scientific literature and SUDS design guidelines, which indicate removal efficiencies ranging from 70% to 89% for total suspended solids, nitrogen, and phosphorus. For organic matter, the constructed wetland operates within the recommended loading range of 20–40 g BOD/m²/day. The information generated provides a valuable knowledge base for the design, sizing, and optimization of similar future interventions.

The system also provides approximately 115 m³ of storage capacity, enabling the retention of rainfall events with a return period of more than eight years. This capacity reduces the volume of water entering the drainage network, improves local hydraulic management, decreases water accumulation in the lowest areas of Oceanía Street, and reduces the pollutant load reaching the Maspalomas coastal wetland. The total reduction of pollutant discharge to local waterbodies is being assessed.

The environmental performance of the NBS is assessed through indicators related to ecosystem quality and biodiversity. Monitoring includes the changes in bird populations associated with the bioretention area and will track the number of plant species as a biodiversity indicator. In addition, the establishment and resilience of the planted vegetation are evaluated to identify the species best adapted to local conditions. The monitoring programme also includes a specific indicator on the presence and evolution of invasive species to assess their influence on ecosystem development.

From a social perspective, the new green infrastructure improves the environmental quality of the surrounding area and enhances residents' well-being by increasing the perception of the space as a more pleasant, accessible, and restorative environment (Check WP2 indicators).

From an economic perspective, the solution has contributed to reducing the costs associated with cleaning operations following Combined Sewer Overflow (CSO) events. These benefits were assessed using the indicators presented below in the Making the Economic Case for Nature section, which also provided the basis for the multi-criteria analysis developed within the project.

The performance of the implemented solution was also assessed under different climatic scenarios. The results show that the NBS maintains its capacity to improve water quality, increases the resilience of the urban drainage system and represents a technically feasible and replicable solution for implementation in other areas of Maspalomas and across the rest of the island.

The analysis carried out in the NATALIE project suggests that investing in NBS can deliver measurable economic returns alongside environmental benefits. Using a 30-year assessment period, the cost-benefit analysis found that benefits outweigh costs under both moderate and high climate change scenarios. Preliminary estimations show that under a moderate scenario, every euro invested is expected to generate €1.14 in benefits. Under a more severe climate scenario, this increases to €1.42, with the initial investment recovered after approximately 14 years (final assessment under preparation).

Perhaps most striking is where these benefits come from. More than half of the total value generated is not linked to avoided damages, but to new economic opportunities created by a healthier environment. Increased tourism attractiveness, biodiversity enhancement, carbon sequestration, recreational value, and green employment together account for 51% of total benefits.

The findings challenge the perception that climate adaptation is primarily a cost. In destinations such as Maspalomas, a healthy environment is central to the local economy, making investments in ecosystem restoration increasingly relevant for both public authorities and private actors.

Detailed cost-benefit analysis is under preparation and will be accessible here in the full report for Gran Canaria (Report Link).

The experience in Maspalomas points to a wider opportunity for Gran Canaria. While the current intervention focuses on a specific catchment, its lessons are already informing discussions about how NBS can be mainstreamed across the island.

The Maspalomas project addresses three critical barriers to NBS mainstreaming: knowledge, governance, and financing. By generating robust technical evidence on hydrological performance, ecosystem outcomes, and co-benefits, the project will demonstrate the viability of nature-based approaches in arid island contexts. This knowledge will be instrumental in designing and refining subsequent NbS interventions across Gran Canaria, building institutional confidence and establishing best practices that can guide future investments. Through this learning-by-doing approach, Gran Canaria positions itself as a leader in adaptive climate strategies.

When it comes to financing these projects, one promising avenue is the development of innovative financing mechanisms that combine public funding with private investment. Because many of the benefits generated by the intervention accrue to the tourism sector, utilities, and property owners, these actors have a clear economic interest in supporting future projects. The Canary Islands' Reserva para Inversiones en Canarias (RIC) could offer a potential pathway for channelling private capital towards environmental infrastructure while providing fiscal incentives for participating businesses.

By combining scientific evidence, economic valuation, and community engagement, the Maspalomas initiative demonstrates how NBS can move beyond isolated pilot projects and become part of a broader climate adaptation strategy.

SUDS can be adapted to a wide range of urban and semi-arid contexts facing stormwater pollution and flash flooding. The mitigation potential, costs and benefits depend on local environmental, social, and economic conditions.

You can use the NATALIE tools to perform a preliminary evaluation of the suitability of this solution for your specific case scenario.