Effectively halt conversion and degradation across freshwater ecosystems

As irrigated agriculture accounts for 69% of freshwater withdrawals, improving water use efficiency in irrigated agriculture (crops, livestock and other uses) is particularly essential to reducing pressures for greater water withdrawals and minimizing ecosystem degradation.

Irrigated water use efficiency (IWUE) in agriculture is measured by value added in U.S. dollars per volume of water used in cubic meters across irrigated agricultural land. IWUE has shown continuous growth, more than tripling between 2000 and 2022. More recently, it increased by 25% between 2018 and 2022.

Existing data, though insufficient to make robust comparisons, indicates variations in IWUE across regions and countries, reflecting differences in irrigation practices, crop types and water management strategies. However, these differences do not show clear regional patterns. For instance, in 2023 the Netherlands had the highest IWUE at 35, while New Zealand at 4.4, Sierra Leone at 3.4, Germany at 2.4, Saudi Arabia at 0.99 and India at 0.65.

To further increase efficiency, efforts should include promoting sustainable agricultural practices, including water-efficient irrigation systems, developing more drought-resistant crops and implementing policies and incentives for water conservation in agriculture. Equitable and effective water governance structures are also necessary for implementing and sustaining efficient water use practices, ensuring fair allocation of water resources and promoting stakeholder participation in water management decisions.

Protected areas and other effective area-based conservation measures (OECMs) are the foundation of efforts to prevent biodiversity loss. Under the Kunming-Montreal Global Biodiversity Framework adopted in 2022, nearly 200 countries pledged to effectively conserve 30% of the world’s ecosystems by 2030 through these area-based conservation measures.

Of all measured inland waters, including wetlands, rivers, streams and lakes, intermittent stream ecosystems were protected at the highest percentage — 32% — with intermediate rivers (18%), small streams (17%) and wetlands (16%) following next.

Although a complete analysis of all freshwater ecosystems within protected areas or OECMs as of 2025 is not yet available, over 2,500 Ramsar sites — wetlands designated to be of international importance and earmarked for protection — were registered by that year, covering almost 260 million hectares (Mha) of the approximately 1,200-1,600 Mha of wetlands around the world. Similarly, more than 3,700 freshwater ecosystems around the world have been designated as Key Biodiversity Areas, indicating that countries have earmarked them for elevated protection.

While the rates of ecosystem conversion are generally lower within protected areas than outside of them, simply establishing a protected area does not eliminate habitat loss. Instead, the efficacy of protected areas and OECMs varies significantly depending on a range of factors, including size, age, proximity to cities, baseline degradation rates, existing human pressures on nearby ecosystems, governance and the degree of human activities allowed within their borders.

The extent to which an entire ecosystem is protected can also impact overall effectiveness; for instance, if only a small part of a river that is home to a fish spawning area is protected, degradation elsewhere in that river may still negatively impact the protected area. Conversely, protected areas may be particularly impactful for small wetlands — often home to disproportionate freshwater biodiversity — even when the full ecosystem can be protected.

Unfortunately, protected areas often neglect the specific needs of freshwater ecosystems. For example, while connectivity is particularly critical for these ecosystems, it is often overlooked. Case studies highlight the importance of both lateral (e.g., river-riparian and floodplain zones) and vertical (e.g., surface-groundwater) connectivity for species survival, but insufficient monitoring efforts prevent a full assessment of the effectiveness of conservation efforts. Freshwater ecosystem conservation also tends to receive fewer resources than conservation of other ecosystems.

In addition, local factors such as the quality of monitoring systems, access to finance and poor law enforcement can also impact protected areas’ effectiveness. Expanding freshwater-based protected areas will therefore need to be coupled with improved management, planning and monitoring and increased institutional capacity and enforcement. Completing a management effectiveness assessment is essential for understanding if a protected area or OECM is meeting its goals in protecting biodiversity.

Vegetated areas adjacent to water bodies, known as riparian buffer zones, maintain ecological integrity and provide ecosystem services. These zones significantly reduce soil erosion and concentration of other pollutants like nitrogen by trapping eroded soil particles, thereby reducing sedimentation in water bodies and contributing to climate change mitigation by sequestering carbon.

The vegetation in riparian zones regulates microclimates, mitigates temperature extremes in both air and water and provides habitats for wildlife, enhancing rich species diversity and ecosystem resilience against climate change. Additionally, healthy riparian zones support agricultural activities by regulating water flow, filtering pollutants, maintaining water quality, enhancing soil fertility, reducing runoff and providing habitats for pollinators essential for agriculture.

Policies promoting riparian buffer zones play an important role in safeguarding water quality, habitats and overall ecosystem health. But, given that no globally comprehensive dataset measures the number of countries that have enacted such policies, more data is needed to assess the extent to which these policies are being implemented in different countries over time.

Critically, even in the countries with regulations for protecting riparian zones, implementation is limited. Key challenges in implementing riparian management include vague policy objectives that lack measurable targets, making effectiveness hard to assess; inconsistent guidelines across regions; socioeconomic pressures in developing countries, where community needs often conflict with conservation goals; a lack of integration in environmental and land-use programs, leading to fragmented protection efforts; and inadequate protections for riparian zones.

Soil health underpins the regulation of green water flows, or the water that infiltrates soil and is taken up by plants. Healthy soils act as a natural reservoir, enhancing infiltration, water retention and slow release to vegetation. When soils degrade through erosion, compaction, nutrient depletion or loss of organic matter, their capacity to absorb and retain green water declines, increasing surface runoff, reducing plant-available water and intensifying vulnerability to droughts and floods. Accordingly, soil degradation poses a significant threat to agricultural productivity, food security and more.

Soil degradation and climate change are closely connected, creating a vicious cycle: Degraded soils lose their ability to store carbon and support vegetation, leading to increased greenhouse gas emissions that drive climate change. At the same time, climate change contributes to and exacerbates soil degradation through changes in temperature, precipitation patterns and extreme weather events such as droughts and floods.

Measures that promote, guide or require agricultural practices aimed at minimizing soil degradation are necessary to maintain soil health, productivity and environmental sustainability, as well as safeguard broader green water flows. These measures encompass a range of sustainable land management practices, including conservation tillage, crop rotation and cover cropping, contour farming and terracing, integrated nutrient management, agroforestry and windbreaks, and sustainable irrigation techniques.

By promoting these practices through comprehensive national policies, economic incentives, research and capacity-building, countries can combat the severe consequences of soil degradation. However, there is currently no comprehensive global dataset tracking national policies aimed at minimizing soil degradation.

Water tenure rights define how people can access, use, manage and make decisions about water resources. Secure and well-defined water rights are central to safeguarding access to water by Indigenous Peoples, Afro-descendant Peoples and local communities and enabling them to manage resources sustainably and equitably.

By contrast, threats to communal waters held by Indigenous Peoples, Afro-descendant Peoples and local communities can undermine water-based livelihoods and deepen water insecurity among already marginalized communities. Recognizing and establishing secure water rights for these communities is therefore critical to protecting their human and territorial rights and supporting sustainable, community-led resource management and resilient livelihoods.

Adapting from the Rights and Resources Initiative (RRI) land and forest tenure methodology, the RRI and the Environmental Law Institute developed a framework that defines community-based water tenure regimes as systems in which a local community has legally recognized rights to use and manage a freshwater resource or decide who is allowed to use it. Examples include the right to manage the rivers and lakes in their region, or to set up and control small-scale irrigation systems stemming from communal freshwater sources.

In their 2020 report “Whose Water?” these partners identified 39 community-based water tenure regimes in 15 countries, providing a baseline for tracking legal recognition of community freshwater rights. The report also evaluated these regimes based on their ability to support community survival, culture, livelihoods and development — particularly for Indigenous Peoples, Afro-descendant Peoples and local communities.

While the report finds that rights to use and govern freshwater exist in 14 of the 15 countries assessed, significant legislative gaps and administrative barriers continue to limit communities’ ability to effectively manage and protect their freshwater resources. Data for more countries is also needed to more comprehensively assess global trends.

In the global freshwater system, corruption can be particularly prevalent in megaprojects commonly associated with water resource development such as hydropower; it can also emerge in other areas of the water sector, from water resources management to drinking water services and irrigation.

Protecting freshwater ecosystems depends not only on governments strengthening conservation policies but also on their willingness to act with integrity and apply the rule of law consistently, including to those with political and economic power.

Abuses of power for private gain can occur across all levels of government. And, in some cases, corrupt interests can become so deeply ingrained within governments that they influence environmental policymaking and legalize actions that harm ecosystems.

According to the World Justice Project Rule of Law Index, corruption is relatively low in roughly 43% of countries, a figure that has remained fairly stable in recent years. The lack of marked progress highlights the need for continued efforts to curb corruption in all its forms. Evidence suggests that in countries with significant freshwater resources — such as those in the Mekong River Basin — corruption continues to pose a challenge. 

Increasing dedicated financial flows to support ecosystem protection, and the local communities using these ecosystems, is vital to limiting warming to 1.5 degrees C (2.7 degrees F) and conserving biodiversity. Despite these measures’ substantial potential to help combat both crises, as well as their relatively low costs and clear co-benefits to sustainable, climate-resilient development, public and private finance lag far behind estimated needs.

Globally consistent, annually updated data on funding dedicated to effectively halting the conversion and degradation of freshwater ecosystems is currently not available. However, the United Nations Environment Programme publishes the State of Finance for Nature, which routinely estimates public and private funds flowing to nature-based solutions, including measures to protect freshwater ecosystems. Its most recent assessment finds that total tracked finance to support these critical solutions reached just $220 billion in 2023, as compared to the estimated $571 billion needed by 2030 to meet global commitments under the Rio Conventions.

This gap is concerning, especially given that the finance flows measured by this indicator are not exclusive to freshwater ecosystem protection and that freshwater ecosystems tend to receive less dedicated funding than other ecosystems.

Worse still, the most recent available evidence also suggests that even these limited funds often fail to reach the local level, where most implementation occurs.