Environmental Flow Policies: Moving Beyond Good Intentions

Eloise Kendy and Tom Le Quesne
Calfornia’s dammed Trinity River is flowing more naturally this year, thanks to an agreement to restore environmental flows.
Calfornia’s dammed Trinity River is flowing more naturally this year, thanks to an agreement to restore environmental flows.
© Conservation Lands Foundation

a river's flow is its heartbeat. Few human influences are more deadly to freshwater ecosystems than alteration of natural hydrological rhythms. Poorly planned dams and unbalanced and unsustainable water use have brought too many of our river systems to a tipping point.

Because we have interfered with the heartbeat of so many rivers and lakes, our freshwater ecosystems are losing species and habitats faster than any other type of ecosystem. Freshwater plants and animals have evolved with, and intimately depend upon, natural patterns of hydrologic variability. Naturally high and low water levels create habitat conditions essential to reproduction and growth, and drive ecological processes required for ecosystem health. The natural rise of a river following a rainstorm may cue fish to move to spawning grounds, or enable them to move up- or downstream to access food, or freshen the water quality so it is more conducive to growth. Similarly, many wetland and floodplain plants reproduce only under certain flow conditions, such as prolonged flood recession.

Patterns of freshwater flows are crucial for a range of other services provided by river systems. For example, flood pulses move sediment that maintains the form and function of rivers. In sediment-rich rivers, such as the Yellow River in China, this movement of sediment is vital in the ongoing management of flood risk. Seasonal inundation of floodplains and wetlands supports groundwater recharge on which water supplies depend. And, the flow of freshwater to estuaries prevents saline intrusion into coastal aquifers and drinking water supplies. The patterns of river flows are therefore integral to water systems on which people depend.

Environmental flows are the seasonally and annually varying water flows and levels that support ecosystems and human livelihoods while providing for other uses such as hydropower, irrigation, and water supply.  Many governments and river-management agencies around the world have developed policies to protect environmental flows, and more are doing so all the time. Yet implementation of these policies remains weak.

Obstacles to implementation

A recent report by WWF and The Nature Conservancy reveals some of the main obstacles to the implementation of environmental flow policies across the world. Policy change alone does not result in implementation. At the highest level, political support for environmental flow policy is essential for setting strategic direction, securing resources, working with stakeholders and enforcing the policy.

Having sufficient capacity is equally key to success. Conducting a thorough assessment and developing operational rules for environmental flows at even a single dam requires significant technical and institutional capacity. A comprehensive framework for implementation requires that relevant laws, policies, regulations and institutions be in place across a wide range of water resource management functions.

Conflicts of interest can waylay the best plans. Environmental flows are inherently interdisciplinary, and may involve agencies that plan and manage hydropower, agriculture, land use, industrial development and natural resources. The conflicts of interest only intensify on transboundary rivers.


While there is no single correct approach to environmental flow policy implementation,  lessons are beginning to emerge from the growing body of international experience. We propose the following guidelines:

  • Undertake a phased approach to implementation. In many of the world’s environmental flow success stories, implementation started with simple approaches in select locations, and evolved to encompass more comprehensive and sophisticated approaches nationwide. South Africa’s landmark 1998 water law, which prioritized environmental flows over economic water uses, was initially stymied by an inability to quantify, allocate, and enforce those flows throughout its large and diverse territory. Eventually, by phasing implementation geographically and by adopting an assessment hierarchy which prioritized the most important rivers, South Africa is now making strides toward implementing its inspirational policy.
  • Be opportunistic. Institutional barriers can often be overcome by introducing and implementing environmental flow policies opportunistically. Opportunities may take the form of water resource planning, creative interpretations of existing policy, legal challenges or other crises such as social reform, or climate change. Being opportunistic may simply mean finding the right legal instrument. Mexico’s lack of a clear policy regarding water re-allocation to the environment did not deter river advocates in the Colorado River delta, who saw an opportunity in the existing legal framework. Although no precedent exists for stopping irrigation to improve stream flows, moving water rights from one irrigated parcel to another is a well-established practice in Mexico. By changing the locations of irrigation rights from cropland to natural floodplain wetlands, they successfully re-allocated ecological flows to the delta without officially changing the uses associated with their water rights.
  • Don’t exceed available capacity; build capacity into the process. A common temptation is to adopt approaches that are too sophisticated for the available local capacity. It is important that at any given time the policy, methods, and approaches are within the ability of the existing institutions to actually implement them. When Florida’s (USA) water policy was reformed in 1972, it was considered visionary and potentially unachievable. However, progressive implementation of the policy in sync with capacity building has enabled methodology improvement, extensive data collection, and increasingly sophisticated environmental flow provisions over time. Nearly 40 years later, the reform survives and has established Florida’s leadership in comprehensive, science-based environmental water management.
  • Limit water abstraction and flow alteration as soon as possible. It is much easier to impose requirements on new users than to enact changes to existing use. It is better to introduce a cap now that can be relaxed later if warranted than to allow water use to impair ecosystems, resulting in the need for difficult future re-allocation processes. Even in basins that are truly over-allocated, however, a cap should not prohibit new water uses. Instead, it is the cap on new withdrawals that incentivizes legal, financial, and technical innovations for managing limited resources efficiently. These include water transactions, as in Australia and the western USA, as well as engineering solutions involving dam re-operations, for example. Many measures that drive efficient water use – water transactions, conservation, re-engineering, and other innovations – simply will not occur in the absence of an effective cap on new withdrawals.
  • Develop a clear statement of objectives based on an inclusive, transparent and well-communicated process. Support for environmental flows is bolstered where a clear, high-level statement of objectives is achieved at the national policy and river basin level, involving as broad a range of groups, interests, and stakeholders as practical. This can secure the political commitment required to ensure that implementation occurs. The shared vision need not call for a uniform level of protection for all water bodies across a jurisdiction. For example, highly biodiverse areas may receive greater levels of protection than highly utilized areas in economically important regions. Many governments, including South Africa, Maine, and Connecticut, have established stakeholder processes for classifying water bodies according to river condition goals that correspond to different degrees of allowable flow alteration. Interstate agreements pose special challenges, since each state is a stakeholder representing multiple stakeholders within it. The Mekong River process stalled in the absence of a shared vision among states. In contrast, the Great Lakes Compact directly addresses the common goal of protecting water resources within a shared basin in the US, and implementation is progressing on schedule.
  • Develop a clear institutional framework, with independent oversight. Transparent, effective institutions and rules for water allocation and management are critical precursors to effective environmental flow policy; if they are lacking, then comprehensive water policy reform may be essential. Independent oversight is an important element of an effective institutional framework. Institution building can be a long and complex process.  Nearly a decade after passing its first national Water Act, the government of Kenya has only recently established an independent national Water Resources Management Authority and six regional Catchment Area Advisory Committees to carry it out. Likewise, Australia has been comprehensively reforming its water sector for more than 15 years to address growing concerns over the deteriorating state of the country’s rivers.
  • Create sustainable financing mechanisms. Environmental flow programs, like any other government program, require sustainable funding. Revenue sources may range from general taxes to fishing license fees to hydropower compensation funds and water markets. Conflicts of interest may arise if ongoing institutional functions are funded by the regulated community through water use fees, as this incentivizes financially strapped agencies to issue excessive water use permits.
  • Conduct proof-of-concept pilot projects. Successful local pilot projects build technical capacity and political support, and show that implementation is possible at much larger scales. The engagement of stakeholders in pilot projects ensures buy-in and builds trust that catalyses broader policy reform.  National environmental flow programs from Costa Rica to Lesotho were inspired and informed by successful local pilot projects.
  • Allow flexibility for implementation methods, while setting a clear deadline and goals for implementation. Programmatic flexibility is important for adapting approaches according to learning and local circumstances. Some flexibility allows for pragmatism; too much, however, can prevent administrations from being held accountable. Deadlines for implementation counterbalance flexibility and ensure progress.

As reform efforts from every continent demonstrate, it is one thing to pass ambitious, high-level laws and policies, and quite another to implement the on-the-ground actions that protect and restore environmental flows. It is at the implementation stage that policy reforms come face to face with challenging realities, from political opposition to capacity constraints to institutional barriers. Yet case after case from around the world show that by undertaking a deliberate, incremental process over time, meaningful outcomes can be – and are being – achieved.

Dr. Kendy (The Nature Conservancy), and Dr. Le Quesne (WWF) are co-authors of the report.

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