This action is intended to promote the infiltration of rainwater and the reduction of rainfall runoff, through the promotion of retention basins in green areas.

It also includes an important social dimension, because of the need to alert urban gardeners about good practices in water use.

This action is be supported by the Lisbon Drainage Master Plan (2016-2030), whose objectives have a close relationship with adaptation to climate change.

Expected sub-actions:

• Improvement of the retention basin at the lake in Bela Vista south

Currently, this 200 m2 retention basin has some weaknesses that compromise its performance and usefulness. This sub-action aims to improve the basin and renew the aquatic plants, contributing to a healthy habitat that can support aquatic biodiversity without compromising water saving and retention capacity.

• Installation of an area of ​​zero rainwater waste at LNEC

• Although all tender documents have been launched, it was not possible to carry out the initial sub-action 3.2 – Installation of an area of zero rainwater waste at National Civil Engineering Laboratory (LNEC). The tender for this contract had no interested company, which led to its cancellation and closure of the respective procedure at the end of 2023.  However, considering that we requested an extension to complete the planting activities, we took the opportunity to propose an adjustment to this sub-action, and to consider a possible prototype for a monitoring system in a public area where infiltration and retention basins had already been implemented (Gonçalo Ribeiro Telles Park in Praça de Espanha). In addition, it was important to continue the partnership with LNEC. The implemented solution includes the creation of a local monitoring station, consisting of the following equipment:

A system for measuring the flow of inflow to the drainage network;
A weather station;
An air quality measuring station;
A noise station;
Two piezometers.

In addition to the monitoring equipment, within the scope of this sub-action, the installation of interpretative panels on Biodiversity is included. These panels represent an opportunity to enhance the natural heritage of the park and strengthen its pedagogical and environmental awareness dimension. The information presented in the panels will be permanently updated through a biodiversity data collector created on the citizen science platform Biodiversity4All/iNaturalist, with the following ULR (the respective QR Code appears on all panels): https://www.inaturalist.org/projects/biodiversidade-do-parque-goncalo-ribeiro-telles

• Implementation of a pilot for water management in urban gardens and training of gardeners

This sub-action aims at reducing water consumption in urban gardens. The regulation of horticultural parks does not allow automatic irrigation systems, to promote human presence in the parks. Irrigation is therefore a 100% human process, and water consumption is high.

Thus, this sub-action involves the installation of individual water meters to make water consumption more conscious and sessions addressing issues of irrigation efficiency, soil organic matter, integrated soil conservation actions and plant selection. 

As a result of this sub-action guidelines on water consumption sustainability are developed, to be applied in other urban garden areas. 

Results:

Improvement of the retention basin in the lake at Bela Vista Sul

In the medium and long term, this initiative will strengthen the city's network of real-time environmental monitoring stations, making it possible to quantify the cost-benefit of nature-based solutions in climate adaptation.

Strategic point in the drainage network, integrated into the Alcântara basin, responsible for draining two-thirds of the city;

Space built in close relationship with nature, less demanding in terms of maintenance and irrigation, and enriched in biodiversity.

This action, implemented in 2025, allows monitoring the co-benefits resulting from the transformation of an urban square into a green park:

Connection between the Green Corridor of Monsanto Forest Park and the city center;

The retention basin implemented in 2024 is a Nature-Based Solution (NBS) of relevance to the Bela Vista Sul Urban Park, with the potential to be replicated in other green spaces in the city.