Rio Grande Pueblos Irrigation Infrastructure Improvement Act

Rio Grande Pueblos Irrigation Infrastructure Improvement Act - Directs the Secretary of the Interior, acting through the Commissioner of Reclamation, to: (1) conduct a study of irrigation infrastructure for 18 Rio Grande Pueblos in New Mexico; and (2) develop a list of projects recommended to be implemented over a 10-year period to repair, rehabilitate, or reconstruct such infrastructure.

Directs the Secretary: (1) in developing that list, to prioritize the projects recommended for implementation based on consideration of specified factors, including the extent of disrepair, economic and cultural impacts, and overall benefits of the project to efficient water operations; and (2) to notify each Rio Grande Pueblo in writing, inviting the Pueblo to consult with the Secretary regarding the study if it notifies the Secretary in writing of such intent within three months after receiving notice.

Authorizes the Secretary (subject to specified limitations) to provide grants to the Pueblos to plan, design, construct, or otherwise implement recommended projects to repair, rehabilitate, reconstruct, or replace Pueblo irrigation infrastructure to: (1) increase water use efficiency and agricultural productivity for the benefit of a Pueblo; (2) conserve water; or (3) otherwise enhance water management or help avert water supply conflicts in the Rio Grande Basin.

Sets the federal share of the project's cost at 75%, with an exception based on financial hardship.

Provides that nothing in this Act shall affect existing project-specific authority, U.S. responsibilities to any such Pueblo, Pueblo water rights, state water law, or an interstate compact governing water.