Iowa Noname18 is a privately owned earth dam located in Harrison County, Iowa, near Missouri Valley. Built in 1961 by the USDA NRCS, this dam serves multiple purposes including fire protection, stock, and small fish pond management. With a height of 37 feet and a length of 450 feet, the dam has a storage capacity of 148 acre-feet and covers a surface area of 5 acres.

Managed by the Iowa Department of Natural Resources, Iowa Noname18 is regulated, inspected, and enforced to ensure compliance with state regulations. The dam's spillway type is uncontrolled, with a low hazard potential and a moderate risk assessment rating of 3. While the condition assessment is currently not rated, the dam is deemed to be in good standing overall.

Situated along the TR-Soldier River in the Omaha District, Iowa Noname18 plays a crucial role in water resource management in the area. With its historical significance dating back to the early 1960s, this dam continues to contribute to the local ecosystem while providing essential services for fire protection, livestock, and recreational purposes.