Mosquito of Harrison B is a local government-owned earth dam located in Neola, Iowa, along the TR- Mosquito Creek. Built in 1987 by the USDA NRCS, this dam serves multiple purposes including fire protection, stock watering, and small fish pond management. With a height of 31 feet and a length of 590 feet, it has a storage capacity of 20 acre-feet and covers a surface area of 1 acre. Despite being categorized as a low hazard potential structure, it is considered to have a moderate risk level (3) due to its location and potential impact in case of failure.

The dam is not state-regulated and does not have any associated structures or inspection history. It is primarily funded and designed by the Natural Resources Conservation Service and falls under the jurisdiction of the Rock Island District. With no outlet gates or spillway control, Mosquito of Harrison B relies on an uncontrolled spillway for excess water discharge. While its condition assessment is marked as 'Not Rated' and there is no Emergency Action Plan in place, the dam is still considered to be in moderate risk due to its age and lack of recent evaluations. For water resource and climate enthusiasts, this structure serves as a reminder of the importance of regular maintenance and monitoring of aging infrastructure to prevent potential hazards and ensure public safety.