The Inter-American Development Bank contracted K&M Advisors to develop a best practices guide for the extraction and sustainable use of water in hydrogen production through electrolysis, with particular emphasis on processes that incorporate desalination. In addition, prepare a methodological guide for evaluating the “water” attribute within the regional CertHiLAC certification scheme, with the objective of promoting robust and harmonized environmental criteria across the clean hydrogen value chain in Latin America and the Caribbean. As part of this assignment, K&M is responsible for: (i) comprehensive review and update of the attached Best Practices Guide for Water Use in the Clean Hydrogen Value Chain; (ii) determine water withdrawal for clean hydrogen production through water electrolysis in the region, and the expected increase in water demand according to clean hydrogen and derivatives development projections in the short term (2030), medium term (2040), and long term (2050), with emphasis on water-scarce countries such as Mexico, Brazil, Colombia, Uruguay, Chile, Peru, and the Dominican Republic; (iii) analyze water withdrawal in comparison with the main alternative uses: mining, agriculture, industry, and residential use; (iv) analyze and quantify the direct, indirect, and cumulative effects of water withdrawal for clean hydrogen and derivatives projects, using both individual project-level and regional approaches; (v) develop the necessary mitigation measures and best practices to reduce impacts, complementing the existing Best Practices Guide; and (vi) establish a specific guide for evaluating the water attribute under the CertHiLAC Regional Certification Scheme.