The purpose of the Water Preservation and Affordability Act of 2025 is to enhance the Federal Water Pollution Control Act by incorporating resource preservation techniques into various water management programs. The goal is to improve water efficiency, energy efficiency, and sustainability in water-related projects. Key provisions of the Act include a new definition of "resource preservation technique," which encompasses methods that promote water reuse, energy efficiency, stormwater management, sustainable project planning, and environmentally innovative practices.