The FLOWS Act amends federal hydropower licensing rules to streamline maintenance and repairs at existing hydroelectric projects and create a new expedited licensing pathway for small water energy systems. For existing hydropower facilities, the bill allows routine maintenance and temporary operational adjustments without federal approval, while requiring the Federal Energy Regulatory Commission to establish clear regulations within 180 days distinguishing between routine work and major alterations that still need approval. The bill also creates a new licensing category for micro hydrokinetic projects (facilities generating up to 5 megawatts from waves, tides, currents, or free-flowing water), with licenses lasting 10 to 20 years and a streamlined approval process requiring the Commission to issue final decisions within one year of application. The legislation requires the Commission to report to Congress within five years on the environmental and economic impacts of these newly licensed small projects. Overall, the bill aims to reduce regulatory burden on existing hydropower operators and accelerate deployment of small-scale renewable water energy projects.