Not a drop goes to waste with a recycled water programme and rain-fed greenspaces

Location: Lisbon, Portugal

Population: 2,719,000 (urban area)

Climate: Mediterranean

Duration: 2019-2025

Sector: Water

Funding sources: Public

City networks: C40

Savings: The city is already saving 10% on the cost of recycled water over potable water.

Solutions: Lisbon is securing its water supply for the future by protecting drinking water reserves and expanding the use of recycled water for various city purposes.

Multiple benefits: Social, health, economic and environmental co-benefits.

Droughts are growing more severe and frequent in Southern Europe, with Portugal suffering extended droughts in recent years. Although Lisbon’s water supplies are not in immediate danger, the city has found an opportunity for improvement.

Objective – The goal is to have a recycled water network throughout the city (source).

Solutions – Rather than flushing drinking water down the drain, Lisbon has established a strategy to maximize the use of recycled wastewater for non-potable purposes, which has the added benefit of emitting half the greenhouse gases that potable water does.

The construction of a city-wide recycled water distribution network and a working group to ensure water quality public safety are among Lisbon’s Strategic Plan for Water Reuse goals. The strategy is part of a larger Water Efficiency Strategy, which is based on a vision of a city with resilient green infrastructure that uses the least amount of water possible. Rain-fed native species are used to plant greenspaces, reducing irrigation requirements. When irrigation is employed, a system is installed to detect and repair water leaks quickly and efficiently. Lisbon has added greenspace by more than 10% in the last decade, intending to reach 20% by 2021.

Funding – With a municipal investment in the order of 16 million euros, it will be implemented in 3 phases until 2025 (source).

Innovation –Before the initiative, there was no existing regulation regarding re-use water quality or a regulatory framework for the distribution and pricing of this new water product. These activities were spearheaded by a working group that included representatives from the governmental, private, and academic sectors.

Success factors – 1) Invest in the future: Previously, Lisbon relied on tankers to transport reclaimed water; now, it has adopted a more permanent and efficient alternative. 2) Be open to non-traditional resources: Public acceptability of recycled water was an early worry in the project’s development, which was handled by a thorough investigation and action plan to mitigate any potential health risks. The municipality anticipates that the community will receive the project well as severe droughts become more frequent.

Significant outcomes

• The city has proposed a new business model for introducing recycled water, enabling chances for more inexpensive and sustainable water sources to be integrated into a wide range of businesses such as cooling systems;
• By increasing the city’s greenspaces without increasing water consumption, the city will retain its water reserves while enabling the use of green infrastructure as an effective tool for heatwave adaptation.

Synergies with local policies:

• Lisbon Strategy for Adaptation to Climate Changes, approved in 2017, presents water as an important in the city’s climate adaptation plans. Water efficiency initiatives have already reduced municipal water consumption by 17%. Meanwhile, drainage and recycling activities will assist the city address local concerns, including rising sea levels and heavy rainfall;
• Lisbon Resilience Action Plan (RAP). Lisbon designed the RAP around its city limits (urban area). The current planning horizon is ten years, from 2020 to 2030, aligned with the Lisbon strategic planning objectives. This plan aims to improve climate change resistance by focusing on water;
• Lisbon Sustainable Energy and Climate Action Plan. The City of Lisbon has signed the European Covenant of Mayors’ 2030 pledges. It presented an ambitious Sustainable Energy and Climate Action Plan to cut CO2 emissions by 70% by 2030 and become carbon neutral by 2050.

Political alignment:

• National Water Plan and 15 River Basins Plans. This plan was developed in Portugal after assessing the current water resource status, the challenges of a new policy approach, socio-economic development possibilities, and the key water resource demand. A timetable for their implementation and assessment are established in these Plans;
• The National Water Plan (PNA). It establishes the country’s coordinated water management strategy. It outlines the major options for the national water policy and the policy’s concepts and guiding principles, which will be implemented through hydrographic region management plans and other water planning instruments.

Marketability: Lisbon’s bold initiatives to use recycled water influence national and EU policy, allowing smaller cities to follow suit.