The Hydropower Sustainability ESG Gap Analysis Tool (HESG Tool) enables hydropower project proponents and investors to identify and address gaps against international good practice.

Example report card from a HESG assessment.

Example report card from a HESG assessment.

The HESG Tool is based on the framework of the Hydropower Sustainability Assessment Protocol (HSAP). It assesses projects against the requirements of the HSAP’s environmental, social and governance topics. 

The tool provides an action plan to help project teams address any gaps against good practice. It is divided into 12 sections which are compatible with IFC’s Environmental and Social Performance Standards and the World Bank’s new Environmental and Social Framework.

Origin and governance

A key driver in the development of the HESG Tool was the demand for an effective, lower cost alternative to a full HSAP assessment which is accessible for projects seeking eligibility for green or climate bond financing. The HESG Tool was developed by International Hydropower Association (IHA) between February 2017 and June 2018 under the mandate of the Hydropower Sustainability Assessment Council, with the support of the Swiss State Secretariat for Economic Affairs (SECO).

To ensure the highest quality and rigour in the assessment process, all commercial use of the HESG Tool is carried out by accredited assessors. These assessors have significant experience in the hydropower sector or with relevant sustainability issues, and have passed a rigorous accreditation course with specific training on the assessment principles of both the HSAP and the HESG Tool.

Topics Covered

The 12 sections of the HESG Tool cover the environmental, social and governance elements of the HSAP:


Labour and Working Conditions

Downstream Flows, Sedimentation, and Water Quality

Project Affected Communities and Livelihoods

Infrastructure Safety


Biodiversity and Invasive Species

Indigenous Peoples

Cultural Heritage

Environmental and Social Issues Management

Climate Change Mitigation and Resilience

Communications and Consultation

Governance and Procurement