A set of indicators transparently assesses the health of freshwater systems in their ecological and social dimensions, quantifying and mapping the multiple benefits that freshwater naturally provides.

The Freshwater Health Index focuses on three main components:

Ecosystem Vitality: The integrity and functioning of the ecosystem itself.

Ecosystem Services: The benefits to people provided by a freshwater ecosystem.

Governance & Stakeholders: The structures and processes by which people make decisions related to water resources.

Each of these components is assessed with a suite of measurable indicators that are aggregated into an index. Evaluation of the indicators requires hydrologic and water allocation models, ecosystem service models, valuation techniques and stakeholder surveys.

Water Quantity

Definition: Amount and flow of water through the basin. 


Water Quantity is determined by assessing the following sub-indicators:


1) Deviation from Natural Flow: The degree to which current water flows have shifted from historic, natural flows.


2) Groundwater Storage Depletion: Changes in the availability of water stored in aquifers.

Water Quality

Definition: The state of water quality necessary for maintaining healthy aquatic ecosystems, rather than for human consumption.

Basin Condition

Definition: The extent of physical modifications to land cover and streams, rivers and channels.


Basin Condition is determined by assessing the following sub-indicators:


1) Bank Modification: the percentage of channelization or human-caused disturbance to stream banks, affecting the size and effect of floodplains.

2) Flow Connectivity: the fragmentation of the stream network, due to natural and human-made obstructions that affect fish passage.

3) Land Cover Naturalness: Alteration of the land cover from its natural undisturbed state.


Definition: Population status and trends of species that depend on freshwater ecosystems.


Biodiversity is determined by assessing the following sub-indicators:


1) Species of Concern: Threatened aquatic or riparian species and other species of particular interest to the basin.


2) Invasive & Nuisance Species: Alien species in the ecosystem that thrive at the expense of native species.


Definition: Physical outputs (primarily water and fish) of freshwater ecosystems for human benefit.


Provisioning is determined by assessing the following sub-indicators:


1) Water Supply Reliability:  The ability to meet water demand from various sectors, with respect to total water available.


2) Biomass for Consumption: Fish, wild food and other materials people harvest from freshwater ecosystems.

Regulation & Support

Definition: The indirect benefits of freshwater ecosystem that either support provisioning services or reduce hazards.


Regulation & Support is determined by assessing the following sub-indicators:


1) Sediment Regulation: The degree to which the drainage basin regulates erosion and controls sediment transport and deposition.


2) Water Quality Regulation: The ability of the freshwater ecosystem to deliver water of the required water-quality standards for different sectors.


3) Flood Regulation: Exposure of people and property to floods.


4) Disease Regulation: Exposure to water-associated diseases such as dengue, malaria, Cryptosporidium and schistosomiasis.


Definition: Non-material benefits or experiences that people receive from freshwater ecosystems.


Cultural is determined by assessing the following sub-indicators:


1) Conservation Areas: The water-related natural resources and structures that are under protection or formal management for science, culture, religion or other values.


2) Recreation: Time people spend engaging in recreational activities that depend on freshwater ecosystems.

Enabling Environment

Definition: Policies, regulations, market mechanisms and social norms used in governing and managing freshwater resources.


Enabling Environment is determined by assessing the following sub-indicators:


1) Water Resource Management: Degree to which institutions are performing key management functions such as coordination, planning and financing, and conflict resolution.


2) Rights to Resource Use: The clarity of rights to water and water-related resources.


3) Incentives and Regulations: Availability of different management instruments, such as impact assessments and economic incentives.


4) Financial Capacity: Investment gap between allocated and required finances for water resource protection measures.


5) Technical Capacity: The number and skill level of professionals working in water resource management.

Stakeholder Engagement

Definition: The ways stakeholders interact and the degree of transparency and accountability around these interactions.


Stakeholder Engagement is determined by assessing the following sub-indicators:


1) Information Access: Accessibility of data on water quantity, quality, resource management and development.


2) Engagement in Decision-Making Processes: Scope of stakeholders involved and the degree to which they have a voice in the cycle of policy and planning.

Vision & Adaptive Governance

Definition: Capacity to collect and interpret information, and then use this information to set goals for the basin and adapt to changing circumstances.


Vision & Adaptive Governance is determined by assessing the following sub-indicators:


1) Strategic Planning and Adaptive Governance: Degree to which comprehensive strategic planning at the basin or sub-basin scale takes place and whether the capacity to adapt plans to new information or changing conditions exists.


2) Monitoring and Learning Mechanisms: Adequacy and use of physical, chemical and biological monitoring of water resources, as well as socioeconomic data, to guide policy and planning.


Definition: Outcomes from water-related policies and investment decisions.


Effectiveness is determined by assessing the following sub-indicators:


1) Enforcement and Compliance: Degree to which laws are upheld and agreements are enforced.


2) Distribution of Benefits: Impacts of decisions about water resource management, with special attention to vulnerable populations.


3) Water-Related Conflict: Presence of conflicts over water services, including allocation, access, pollution, diversion or infrastructure development.