Policy Options to Support Climate-Conscious Urban Water Planning

Abstract

Urban water systems are increasingly vulnerable to climate change. Traditional planning, often based on past conditions, fails to address these new challenges. We suggest policy options for integrating climate scenarios into urban water planning, which will enhance the resilience of drinking water, wastewater, and stormwater systems. The policy options are (1) requiring climate scenario analysis in planning processes, (2) developing climate-resilient infrastructure standards, (3) promoting low-impact development and nature-based solutions, (4) creating regional planning bodies, (5) educating professionals for climate-responsive planning, and (6) securing funding for climate adaptation. We discuss our experience in the state of Utah, USA, and summarize case studies in Copenhagen, New York, and Melbourne. The policy options align with Sustainable Development Goals and offer a roadmap for building adaptable, sustainable urban water systems.

1. Introduction

As the global climate diverges from its past conditions, the need to integrate climate scenarios into urban water planning becomes increasingly important. Urban water systems, including drinking water, urban irrigation, wastewater, and stormwater systems, are directly exposed to climate impacts. Rising temperatures, altered precipitation patterns, and more frequent extreme weather events challenge traditional approaches to water management, yet planning processes often rely on historical data and implicit assumptions that the future will resemble the past. This outdated approach overlooks potentially profound changes in climate, threatening the sustainability and resilience of urban water services.

We discuss why urban water systems need climate-conscious planning and outline six policy options: (1) requiring climate scenario analysis in planning processes, (2) developing climate-resilient infrastructure standards, (3) promoting low-impact development and nature-based solutions, (4) creating regional planning bodies, (5) educating professionals for climate-responsive planning, and (6) securing funding for climate adaptation. We then summarize successful cases and discuss the cases and policies in context.

2. The Need for Climate-Responsive Planning

Climate change presents a multifaceted threat to urban water systems. For drinking water, the reliability of supply is at risk due to changing precipitation patterns, reduced snowpack, and more frequent droughts. Warmer temperatures can exacerbate water quality issues by increasing the risk of algal blooms and other contaminants. These changes require a reevaluation of water sources, treatment processes, and storage capacity. Wastewater systems are similarly vulnerable. Increased rainfall intensity can overwhelm combined sewer systems, leading to more frequent and severe sewer overflows, and rising sea levels threaten coastal wastewater treatment facilities. Stormwater systems, designed to handle runoff from rainfall events, are particularly challenged by the increasing frequency and intensity of storms, leading to higher risks of flooding and infrastructure damage. Standards for design storms are becoming outdated.

Despite these challenges, urban water planning often overlooks the implications of climate change. Some developing countries struggle with basic planning and governance of infrastructure, while in most developed countries, water infrastructure is highly regulated. Whether developing or developed, all countries should engage in planning that considers climate change. Where regulation does exist, it often rigidly and unintentionally [1] locks onto a single conservative value rather than a range of possible scenarios. Many plans focus on projections of population growth, water demand, and land use changes, assuming that future climatic conditions will be similar to those of the past. This assumption leaves water systems vulnerable to the very conditions they are likely to face and for which they should be designed.

To build resilient urban water systems, it is essential to integrate climate scenarios into every stage of water management. This requires a shift from reactive to proactive planning and from viewing climate as stationary to nonstationary. In a complex global climate system, uncertainty abounds and newcomers trying to make decisions may be paralyzed by talk of ensembles, concentration pathways, and GCMs. Still, the concept of resilience should be motivating: When disruptions occur, urban water systems so critical to daily life need to fail safely and then swiftly recover [2].

3. Policy Options for Climate-Integrated Urban Water Planning

With the foregoing discussion in mind, we present the following six policy options (Figure 1).

3.1. Incorporate Climate Scenario Analysis in Planning Processes

One option is to mandate climate scenario analysis in urban water planning. The requirement from regulatory agencies might extend to all water systems or just those of a certain size or risk category. The requirement would ensure that climate impacts are systematically considered in planning, design, and operation. High-level endorsement of climate scenario planning can allow flexibility to fine-tune climate models and develop more prescribable, “streamlined” analysis tools [3]. For example, urban water utilities might use CREAT [4,5] or equivalent tools to evaluate climate change scenarios specific to water infrastructure like increased storm intensity or decreased water supply availability. Others might apply a safety factor to existing results to account for climate variability that was not previously considered. Either way, such an analysis could be a condition for receiving federal or state funding for water projects. Incorporating climate scenarios will increase redundancy in system capacity, and redundancy improves resilience.

3.2. Develop Climate-Resilient Infrastructure Standards

Infrastructure design standards must be updated to reflect the realities of a changing climate. Current design criteria, often based on historical climate data, are inadequate for future conditions. “That assumption is what we rely on to design and build infrastructure projects that are safe and long-lived”, said one expert [6]. “Now, these climate-based engineering standards are no longer reliable. We have to revise our codes, standards, and practices”. Stormwater systems designed for a 100-year storm may no longer provide adequate protection if the frequency and intensity of such events increase [7]. New standards should incorporate the latest climate normals and provide guidance on designing infrastructure that can perform in a range of climate scenarios due to large uncertainties in current projections [8]. These standards would help urban water systems adapt to changing conditions, making them fail less (but not necessarily never) and recover faster, thus increasing resilience. Professional societies, government agencies, and other groups are already working on such standards [9], and water professionals can participate and soon adopt them.

3.3. Promote Low-Impact Development and Nature-Based Solutions

Low-impact development (LID) and nature-based solutions (NBS) offer sustainable approaches to enhancing urban water resilience [10,11]. Features include bioswales, rain gardens, and restored wetlands, which can mitigate the impacts of climate change by absorbing excess rainwater, reducing heat island effects, enhancing biodiversity, and sequestering carbon. Practically speaking, LID and NBS provide deliberately lower topography for stormwater systems to fail safely—without permanent damage or loss of performance—and thereby increase resilience. The technologies are well established, but policy support is needed to tip infrastructure planning preferences from hard to soft, from gray to green. Many regulatory agencies have become “path dependent”, or rigorously, even if not intentionally, stuck in patterns of traditional infrastructure design [12]. An engineer might want to include LID or NBS in a project but might be unsure about compliance or payback and may not have regulatory support to try adaptive measures. Specific policy options to overcome these barriers might include regulatory encouragement, financial incentives, public awareness programs, and technical assistance [13], which are many of the same policies we recommend for climate change response overall.

3.4. Create Regional Climate Planning Partnerships

Water planning does not occur in isolation; it intersects with land use, transportation, energy, and public health. Integrating climate scenarios into water planning requires an approach that fosters collaboration across sectors and scales. Policies should encourage multi-sectoral partnerships and the formation of regional planning bodies that can coordinate climate resilience efforts by leveraging the strengths, knowledge, and resources of multiple parties. Depending on the way in which the regional planning structure is organized, some smaller municipal water systems may initially resist participating in regional planning bodies because they fear losing autonomy or being outvoted by bigger, more influential jurisdictions [14]. However, doing so can also support those systems that would otherwise not have the needed resources themselves but that can benefit from and contribute to regional planning efforts. It will also prevent one municipality from adapting in a way that harms its neighbor. In fact, a collaborative may well use resources allocated to climate-oriented initiatives more effectively than if they were spent on a more local, site-by-site basis [15]. Climate change does not respect municipal boundaries or sectoral jurisdictions, so pooling resources for adaptation is sensible for everyone involved.

3.5. Educate for Climate-Responsive Planning

Climate-responsive urban water planning requires building capability at all levels, from customers to utility operators to policymakers. Training programs, workshops, and educational initiatives should be developed to equip water professionals with the knowledge and skills needed to incorporate climate scenarios into their work. Professional associations can play a major role here through conference programming and publications. Additionally, technical assistance can help smaller utilities and communities that may lack the resources to undertake climate scenario analysis on their own. Policymakers need to be taught about the nonstationary climate and why they should commit to leadership and resources to help urban water systems plan accordingly. This activity contributes to a mindset that supports resilient infrastructure.

3.6. Secure Funding for Climate Adaptation

Financial constraints are one of the most significant barriers to integrating climate scenarios into urban water planning. Without adequate funding, even the most well-designed plans cannot be effectively implemented. Policymakers must advocate for dedicated and sustained funding streams specifically for climate adaptation within the water sector. This support could come in various forms, such as expanding existing federal and state grant programs to include more comprehensive climate adaptation projects. Additionally, offering low-interest loans for climate-resilient infrastructure can help municipalities finance necessary upgrades. Promoting climate-based financing mechanisms for watershed management can also play a critical role [16]. Furthermore, encouraging public–private partnerships can leverage private capital, thereby sharing the financial burden and accelerating the implementation of climate-resilient initiatives [17].

4. Case Studies

We describe below our experience in Utah, where we work and live and have some experience, alongside examples in Copenhagen, New York City, and Melbourne. The cases are not exhaustive and not necessarily representative; nevertheless, they highlight how the six policy options have been implemented in various settings and how governments have chosen to take new steps in water planning.

Table 1. Presence of suggested policies found in case studies.

Policy	Utah	Copenhagen	New York City	Melbourne
Incorporate climate scenario analysis in planning processes	✔	✔	✔	✔
Develop climate-resilient infrastructure standards	✔	✔	✔	✔
Promote low-impact development and nature-based solutions	✔	✔	✔	✔
Create regional climate planning partnerships		✔	✔	✔
Educate for climate-responsive planning			✔	✔
Secure funding for climate adaptation		✔	✔	✔

maps the cases to the suggested policies.

4.1. Utah

In the state of Utah, USA, where we live and work, policy is already evolving in the directions we suggest above. The state’s future water conservation goals include allowances for increased evapotranspiration and longer irrigation seasons associated with urban landscapes due to increasing temperatures [18]. Wholesale water suppliers and a few municipal water retailers are voluntarily considering climate scenarios in their drinking water supply plans, recognizing the likelihood of lower snowpack and earlier runoff. This level of planning exceeds that of typical master plans, which only seek to close the gap between supply and projected but stationary demand. While only a few of several hundred Utah public water suppliers are currently engaged at this level, many of them are located in close proximity and would likely experience the same risks, emphasizing the benefits of regional partnerships for planning and adaptation. We believe that climate-conscious planning will become standard among Utah drinking water suppliers because it is useful, perhaps before it is mandated.

As for stormwater, in 2020 Utah updated its regulations to promote low-impact development. With a few exceptions (e.g., poor soils), new developments must retain the 80th percentile runoff on-site. The state has wisely developed a guidebook with design standards and best management practices [19]. So far we have observed that the design and construction of LID are sound but that maintenance by the utility and/or the customer is the weak link: A well-installed bioswale is soon undone by an unwitting homeowner who fills in what he believes is an undesirable depression, and not a functional water quality and drainage feature, at the edge of his property. Clearer policies on maintenance responsibilities and deliberate education on the function of LID systems would be worthwhile next steps.

4.2. Copenhagen

Copenhagen, Denmark, has developed a comprehensive cloudburst management plan to address the increased risk of flooding due to climate change [20]. This plan integrates climate scenarios into stormwater management by creating new standards that combine traditional infrastructure upgrades, such as expanded drainage systems, with green infrastructure solutions, including parks and permeable surfaces that double as water retention areas during heavy rains. This hybrid approach not only mitigates flood risks but also enhances urban livability. The city cooperated with nearby municipalities in order to preserve the communities’ well-being, and “future work in the city will be a pooled effort with neighbouring local authorities and utility companies” [20]. The project is being funded through a combination of public and private financing, including municipal taxes and utility charges.

4.3. New York City

New York City has integrated climate projections into its water supply management to enhance resilience against climate change impacts and develop metrics to measure that resilience [21,22]. Following Hurricane Sandy (and the disaster-related funding that came with it), the city implemented strategies to protect critical infrastructure from future flooding and rising sea levels through green infrastructure and “blue belts”. The city’s Water Demand Management Plan also includes climate scenario analysis to ensure a reliable water supply, even under conditions of prolonged drought or extreme weather events, safeguarding the city’s future water security. The city’s declared focus in its recent One Water initiative includes prominently a need for education about water stewardship and a specially designed app that connects residents to the harbor’s water quality on a day-to-day basis. Institutions examining regional plans for the city have included the area’s sprawling water and wastewater systems as a core pillar of future infrastructure needs and of future climate risk and resilience assessments.

4.4. Melbourne

Melbourne, Australia, faced severe water shortages during the Millennium Drought, leading Melbourne Water to integrate climate scenarios into its long-term planning and require water utilities in the Greater Melbourne region to include climate adaptation measures in their urban water strategies [23]. With those regional partners, the utility adopted a portfolio approach, incorporating desalination, water recycling, and stormwater harvesting (using LID techniques), all being supported and informed by climate projections. Their water management strategy fosters collaboration and training across public and private stakeholders, aligning water management with urban planning. The adaptive approach has built a resilient, diversified water system capable of withstanding future climate challenges.

5. Discussion

Climate-conscious water planning aligns with several Sustainable Development Goals (SDGs). SDG 6 calls for ensuring the availability and sustainable management of water and sanitation for all, and as crucial steps to achieving this goal, it recommends “capacity-building support to developing countries” and “transboundary cooperation”, two of the policy options illustrated here [24]. SDG 11 emphasizes the need to make communities inclusive, safe, resilient, and sustainable [24], specifically mentioning protecting against water-related disasters and implementing sustainable planning practices [25]. It also highlights planning for mitigation and adaptation to climate change as an important action item for sustainable settlements. SDG 13, which is entirely focused on combatting and mitigating the effects of climate change, calls for integrating climate considerations into both policies and planning efforts, extending education and building capacity for climate response, and securing funding for groups that otherwise would not be able to address the challenges that climate change presents. SDGs 9, 12, and 14 could also be considered immediately relevant to the intersection of climate change and water resources management, although all aspects of sustainability are connected in a globalized world. Climate threats are interwoven into a community’s ability to deliver these goals and cannot be ignored. By incorporating climate considerations into their own urban water planning efforts, cities can contribute to the aspirational SDGs.

The six policies we outline above are being used in the few case studies we have presented. Some are fairly new and their performance has not been measured. They may not be universally applicable or immediately portable outside the case studies to other jurisdictions, climates, or planning programs. Rather, the policies should inspire local, problem-specific solutions that practitioners can pursue. Our purpose here is to bring attention to the elevated level of climate awareness in these cases relative to typical water planning.

The first step is to recognize that it is misguided to plan for a climate like the one in the past. Good planners know that populations change, land uses change, and economies change. No planner would assume that a city’s population would remain static over a period of 40 years, but that is what many of them do with climate. Climate needs to be elevated to the same status as other planning variables before the foregoing policies can be useful. With that mindset, supporting policies will be natural to implement.

6. Conclusions

Integrating climate scenarios into urban water planning is no longer optional. It is necessary. The impacts of climate change on drinking water, wastewater, and stormwater systems are already being felt, and these challenges will only intensify. By adopting the policy options outlined here, governments and utilities can build water systems that are resilient, sustainable, and capable of adapting to an uncertain climate future.

The policy options we suggest have been demonstrated in several cases. They align with global commitments to sustainable development and provide a roadmap for cities to enhance their climate resilience. Many tools and resources are already available; what is needed now is the political will to implement them. By prioritizing climate-responsive planning, we can ensure that our urban water systems continue to provide safe, reliable, and sustainable services for generations to come.