Water systems and climate change put cities at heightened risk

Climate scientists predict that global warming is changing weather patterns, making catastrophic flooding more unpredictable, more frequent and more costly. Since 2000, flood-related disasters have increased by 134%, compared with the two previous decades.³ Flood incidence, damage and costs are rising amounting to losses in the double-digit billions, and overall economic losses totaling in the hundreds of billions, annually.⁴ With USD 135 billion in damages, floods and storms caused the most economic losses in 2021.⁵

The mounting costs of extreme weather expose the vulnerability of many municipal water systems and underscore the need for investments in water infrastructure. Over the years many urban areas have underinvested in water infrastructure; building flood and climate resilience will mean reversing that trend.

The average age of 2.6 million kilometers of water and sewer pipes in the United States is almost 50 years old, with portions stretching back more than a century.⁶ The American Society of Civil Engineers gave the US stormwater infrastructure a dismal D on a scale of A to F and estimates an investment gap of 8 billion annually just to comply with current regulations.⁷ Investments in climate resilience will run even higher. System-wide, to close the water infrastructure gap, investments will need to reach USD 109 billion annually, or over 2 trillion by 2040.⁸ Biden’s recently passed infrastructure bill which devotes nearly USD 50 billion in funding to modernize aging drinking water, stormwater, and wastewater systems will help but still falls short.^9,10

The US is not alone. Segments of the EU’s seven million kilometers of pipes have been in operation since the first World War. Policymakers complain that investment in water infrastructure is not keeping pace with 21st century challenges which in addition to climate change, include population growth and rapid urbanization. An EU report from 2019 estimated flood-related losses in member states to range between EUR 20-30 billion in the 2020s. Losses from 2021 floods in Germany alone were EUR 40 billion, meaning member states have woefully underestimated the cost of future damage.^11,12

All told, the OECD estimates that to achieve sustainable economic growth and development (from flood protection to safe and equitable access), global investments in water infrastructure should reach USD 6.7 trillion by 2030.¹³

The rising incidence of hurricanes, cyclones and typhoons along with rising sea levels, mean the risk of inaction for urban areas along coastlines are accelerating faster then the average.

The island city-state of Singapore is one of the world’s most advanced in developing water management solutions. In addition to a dense network of drains, reservoirs and catchment areas that collect and re-distribute rain waters, local water utilities are also investing in state-of-the-art technologies to help monitor and react to storms in real-time. Storm radar tracks offshore rain volumes while sensors in pipes and valves monitor water network pressure, volume, and quality so loads in mains, pipes and reservoirs can be shifted to maintain system balance. Similar approaches are being advocated in the US, EU to ensure the municipal water infrastructure is climate prepared.

As an alternative to traditional flood resistance infrastructure, coastal cities like Hong Kong and San Francisco are implementing natural solutions to improve climate resilience. Both are developing open green spaces inside city interiors as well as on waterfront borders that act as parks in the dry season but function as massive sponges to soak up excess waters in stormy ones. Washington DC’s water utility recently completed a massive USD 2.6 billion project that combined both innovative green and traditional gray water management measures to keep floodwaters from polluting the Chesapeake Bay. Gray measures included installing underground diversion tunnels while green methods included installing vegetated roofs, permeable pavements, and bioswales (entrenchments along borders to collect runoff) in key areas throughout the city.

Whether green or gray, investing in water infrastructure is capital-intensive early on but given the exponential costs related to climate change, the cost of inaction far exceeds the cost of prevention. Extreme events, together with their extreme costs, are moving from outliers to the norm. To protect not only water supplies but public and private assets, municipalities and companies (many of which operation their own water utilities) should fortify their defenses now.

From smart sensors and precision analytics to massive mains and tunnels, advanced wastewater management to natural watershed maintenance, companies all along the water value chain are providing private companies and public utilities with climate-adaptive solutions that protect water supplies, public infrastructure and human health. Investments in water help dampen climate risk, strengthen climate resilience and keep urban growth and development safely afloat.