Analyzing barriers for stormwater management utilities

This study analyzed barriers for implementing stormwater utilities. Public budget constraints imply a need for prioritizing scarce public funds for financing water-related investment. In this sense, municipalities have ranked stormwater management services as a low priority compared to other public needs, causing them to be underfunded. The creation of stormwater utilities for securing resources should be supported through economic, technical, and legal arguments. There is a global water and sanitation access gap. Municipalities should dedicate themselves more to investigate how these gaps can be reduced, which will bring a higher benefit–cost ratio. Overruling these local governments and financing low priority interventions seems immoral. Furthermore, compulsory charges on public services that supply universal benefits are illegal.


INTRODUCTION
Modern cities show vulnerability to extreme events demanding urban policies to deal with potential impacts, while promoting human health, economic development, and environment sustainability. Over 90% of these extreme events are water related and occur within cities' boundaries, which affect the local hydrological cycle. Floods and waterrelated events account for 70% of deaths and 50% of waterborne diseases (UNEP ).

Globally, every year, inadequate Water and Sanitation
Services (WSS) cause two million deaths (280,000 of these deaths are caused by diarrhea); contribute to malnutrition; and have infected over two billion people with parasites (although mostly are benign). Most of these health impacts occur to children under five years of age (WWDR ).
Urban water management requires a complex integrated system to supply water, meet potential user needs, control water pollution, provide proper treatment of wastewater, manage runoff waters (stormwater), prevent floods, and regulate sustainable use of water resources. A sound water management strategy helps increase environment natural resilience (WMO ; UNESCO ).
Local governments should invest on capacity building and improve urban water management through man-made infrastructure to cope with these increasing global challenges. However, the availability of public funds has decreased drastically. Public decision-making for water-related investments should be based on planning and comprehensive information, which enables clear and effective benefit-cost decisions by each stakeholder (e.g. investors, users, and public officials). Costs are straightforward to assess. However, public officials have demonstrated difficulties in converting WSS benefits in monetary terms (OECD ; Ramôa et al. ).
Public officials have struggled with different methods for ranking water-related investments and efficiently complying with increasing needs and reducing funds. There is a need for improving governance in public-financing processes, which entails distributing responsibilities and actions among stakeholders in the decision-making process (Porse ). In the natural water cycle, part of runoff water reaches the system rapidly, while a large part percolates into the ground, recharging the system in a slow base flow. In the urban engineered water cycle, the constructions over large areas, the compacted soils, and the waterproofed surfaces, increases water runoff and reduces percolation. In both cycles, at different speeds, runoff and base flow embrace their way downstream to the nearest ocean ( Historically, stormwater management services have been financed through public funding from general taxes, but recent budget constraints and increasing population demands impose a severe competition over public funds. (USEPA , ).
In this economic crisis, the preferred alternative has been attracting private investors for financing infrastructure development initiatives. However, sustainable WSS improvements demand better institutional and governance arrangements, which do not occur just by switching the operation from public to private (Pinto et al. ).
Stormwater management, as any public good, competes for financing with several other essential public needs (drinking-water, sanitation, health, education, transportation, and security) within a restrictive public funding scenario. In this scope, stormwater management services have been ranked below other priorities by local decision makers, leading them to be underfunded. For this reason, many municipalities have created utilities to secure proper funding to cover implementation and maintenance costs. In this sense, stormwater governance (narrow) would differ from water governance (broad) as the latter must compete with other demanding services (Porse ; Wang et al. ).
This study analyzed economic, technical, and legal barriers related to the creation of stormwater management utilities for securing public funds impairing more appealing public demands, which overrules public decision-making process. The analysis limited its scope to stormwater man- After this brief introduction, section two discusses the economic barriers in the stormwater services. Section three analyzes the technical barriers and section four the legal barriers. Finally, section five draws the concluding remarks.

ECONOMIC BARRIERS
The United Nations states that adequate access to WSS is a basic human right. Countries are at distinct development stages concerning their water-related infrastructure. Developed countries are demanding compliance with stricter environmental regulations and investing in improving wastewater treatment, while most developing countries still need to make considerable investments in WSS infrastructure to reduce the 'access gap' to water, sanitation, and hygiene services (OECD ; UN ).
In any situation, it is important to guarantee an efficient decision-making process for analyzing, prioritizing, and, selecting water-related investments. Given the current severe public budget constraints worldwide and the substan- Benefits assessment on treating contaminated water relates to improvements of water quality through the removal of different polluting substances, which is hard to calculate due to their inherent diffuse nature. Sequentially, the benefits of stormwater management are even less obvious and tougher to evaluate, especially in places where flooding is not a major challenge.
Local governments have perceived stormwater management as supplying lower BCR than other competing public needs.
The lack of information cannot be a sound reason for prioritizing stormwater investments. Improving information databases and methods on water-related services could help to define the situations in which the stormwater service could be an investment priority (OECD ; Wang et al. ).
There are other obstacles for evaluating benefits because they vary consistently with the actual WSS development stage of a specific country. In developing countries, there is a large 'access gap' so that supplying water and sanitation must be the main priority because these actions deliver the highest BCR. Additionally, hygiene education can also supply enormous benefits at a relatively low cost ( A well established water governance plan should enforce efficient investment decisions, requiring policy makers to gather information on costs and benefits of each different water-related investment. However, investments that produce the highest benefits may also be the most expensive ones. That is the reason why information on benefits alone might not be enough to persuade public officials to invest in a specific water-related activity (e.g. stormwater management), which may not be the most effective use for limited public funds In flood-prone areas, municipalities have raised the necessity for creating utilities to guarantee dedicated financing for existing and future infrastructure to divert runoff waters. However, there are technical barriers for stormwater charging because the assessment of each property contribution to stormwater management is not a simple task.
That is why most stormwater utilities that are trying to make the technical approach easier use a charge scheme based upon impermeable surface ratio as proxy for private properties contribution to runoff waters.
Nevertheless, impervious surfaces ratio does not supply a good estimate of the contibution of runoff waters or properties to stormwater drainage systems, because runoff water patterns vary over space and time according to: (i) diverse runoff rates may occur simultaneously in adjacent areas; (ii) soil types vary over space and depth; (iii) the use and land occupation varies from property to property; (iv) many properties store stormwater for reuse; and (v) some properties have a green infrastructure that can retain stormwater.

LEGAL BARRIERS
Lawfully, stormwater management is a local government responsibility associated with three fundamental goals: urban flood control, water resource management, and environmental protection (NAFSMA ).
Typically, municipalities charge a user fee for funding public services, e.g. drinking water, and wastewater systems.
Historically, stormwater management has been financed by public funds, mostly originated from general taxes. However, as discussed earlier, competition with other public needs has often resulted in the stormwater management services being under funded. Thus, stormwater utility supporters defend that municipalities should create a dedicated funding for supporting drainage services, which are perceived as low priority In this scope, stormwater utilities funding has been operationalized in terms of property taxes or service fees.
Legally, property taxes or service fees approaches will have different consequences in terms of who will pay, what procedures should be followed to implement and collect the charge, and how the funds can be employed. The creation of utilities to supply basic public needs often raises legal concerns leading to judicial disputes. Regulatory systems require that governments should give back what they have collected from general taxes (NAFSMA ).
This study analyzed legal barriers of stormwater utilities services for managing runoff waters using completely separated pipelines and that do not receive any further treatment prior to final release to the environment. The analysis used general law principles to supply a broad legal overview on stormwater charges validity. A customized legal analysis for a specific stormwater utility reflecting a country/state/municipality funding approach is not part of the scope of this study.
In most countries, funding public services with taxes raises a yellow flag on legal legitimacy, because a tax is an amount of money demanded compulsorily for supporting public services that can be individualized (uti singuli) in terms of their incurred costs and generated benefits. As discussed in the previous section, most of the expected benefits from environmental preventive actions, such as flood control, are diffuse (uti universi) and cannot be individualized. The actual incurred costs of individual contribution to runoff water cannot be calculated. Plainly, as utilities cannot individualize the costs, they just find an effortless way to split them. The overall stormwater management costs are divided by a property's impervious surface ratio (simple to calculate), assuming that this is the major root cause for runoff waters leading to flooding events (NAFSMA ).
The fundamental attributes for ensuring user-fee or taxscheme lawfulness are non-discriminatory, reasonable to individual costs/benefits, and voluntary. In stormwater utilities, none of these occurs. The benefits of stormwater utilities affect the environment and the society as a whole (NAFSMA ).
In stormwater tax schemes, it is expected that taxexempt entities (e.g. churches and government) will dispute their obligation to contribute. Usually, governmental properties (street, sidewalks, and parks) are tax exempted, despite being the largest impervious surface contributors. Additionally, there will be social demands for exempting low-income communities. These discriminatory exemptions will create a huge burden on remaining taxpayers, which will destabilize the service funding system, demanding for direct or indirect subsidization (NAFSMA ).
Likewise, any tax-scheme implementation requires formal legislation process, which creates an extra burden for stormwater managers. Stormwater taxes cannot be associated with property taxes because the latter are mostly based on property value, which is irrelevant for determining stormwater management costs, as it is not equitable (NACWA ).
Consequently, many stormwater utilities have implemented a service-fee approach to reduce the risk of litigation. In this sense, stormwater utilities must be user oriented, like water and wastewater utilities; service fees should be based on the use of stormwater management services by each individual property. (NAFSMA ).
The U.S. Supreme Courts ruled that taxes charges are a mandatory common burden, while fees are paid voluntarily; nonetheless both need to generate specific benefits. On several occasions, the U.S. Supreme Courts have ruled that user fees can only be charged non-compulsorily to specific benefit users and cannot be applied to stormwater services as expected benefits are universal. In this way, legal decisions have ruled that mandatory stormwater fees are illegal, because these would be taxes in disguise (NACWA ).
Conclusively, a stormwater management utility implies a compulsory compensation for supplying a flood control service throughout separated drainage systems without runoff water treatment, delivering uti universi benefits that cannot be individualized. Furthermore, these public services cannot be measured in terms of their individual incurred costs, which are usually estimated based on an impervious surface. Moreover, it is an essential service that should be supplied irrespective of any payment in return. Lawfully, stormwater management is a public good that can only be financed through public funds that have originated from general taxes. This is already the situation in Germany, among other countries (Geyler et al. ).

CONCLUSIONS
Worldwide, the low-hanging fruits are related to investments for supplying water, sanitation, and hygiene. In developed countries, most of these high-return BCR were captured in the late 19th or early 20th century when basic water and sanitation infrastructure was provided to the population.
Investments in basic WSS generate larger economic, environmental, and social BCR. This is the public managers' judgment call for ranking stormwater management as low priority compared to other society needs for receiving public funds.
Thus, improving funding for urban drainage became a finance challenge, particularly because in most developing countries there is a severe access gap for more compelling water-related services.
This study analyzed economic, technical, and legal barriers for stormwater management utilities created to control floods through dedicated drainage systems that do not supply any further treatment on runoff waters. The basic assumption for creating a stormwater utility is the essential nature of the service, which imposes the need for overruling municipal authorities that give low priority for drainage investments, causing them to be underfunded. The stormwater management service is an essential service, so that society should bear the costs for operating it. Thus, as a utility, the proper dedicated financing solution will be achieved. Municipal authorities should be focusing on investing their scarce public funds to reduce existing water and sanitation access gap, which entail higher BCR. Overruling local governments and financing low priority interventions is immoral. Likewise, a compulsory stormwater charge for services that supply universal benefits and that should be already funded through existing general taxes is illegal.
Thus, this creation of a utility for securing stormwater dedicated funds is based upon unacceptable arguments.

DATA AVAILABILITY STATEMENT
All relevant data are included in the paper or its Supplementary Information.