S. 3573 amends the Aamodt Litigation Settlement Act, which governs a water rights settlement involving Native American pueblos in New Mexico. The bill allows the completion deadlines for the Regional Water System to be extended if all parties involved—the pueblos, the federal government, New Mexico, the City of Santa Fe, and Santa Fe County—mutually agree that an extension is reasonably necessary. The legislation adds flexibility to the original settlement by enabling parties to adjust timelines without requiring a new law if circumstances warrant delays. This affects water delivery and rights for Native American communities in the Española Basin area of New Mexico. The bill does not establish new funding or specify particular deadlines but rather creates a mechanism for the parties to jointly extend existing completion dates.