While the DDPP reports recognize that pumped storage hydropower is crucial to sustaining our transition to a decarbonized grid, they do not fully account for the potential for environmentally responsible expansion of new conventional hydropower in the United States by 2050. They conclude that conventional hydropower is not expected to keep pace with electricity growth due to sustainability and resource constraints. Yet, additional hydropower development above current levels—both conventional and pumped storage—that meets modern environmental requirements must be a component of any proposal to reduce the United States’ dependence on carbon over the long term. Realizing the full potential of hydropower and even maintaining the current hydropower fleet will likely depend on overcoming a number of impediments to hydropower in the United States. Such impediments include lengthy and complex regulatory requirements, failure of the organized electricity markets to adequately compensate hydropower generators for the grid benefits they provide, environmental opposition to new hydropower, and interest in dam removal. These challenges can be overcome with targeted legal and policy reforms that would not roll back environmental standards.