Osullivan, also known as Potholes, is a fascinating earth dam located in Grant, Washington, with a primary purpose of flood risk reduction. Completed in 1948, this Federal-owned structure stands at a height of 200 feet and has a maximum storage capacity of 546,300 acre-feet. Its design allows for multiple uses, including hydroelectric power generation, irrigation, and navigation, making it a vital resource in the region.

Managed by the Bureau of Reclamation, Osullivan boasts a controlled spillway with a width of 96 feet, ensuring efficient water discharge during periods of high flow. With a hazard potential rated as high and a risk assessment indicating a very high level of risk, this dam plays a crucial role in mitigating flood risks and safeguarding the surrounding areas. Despite its age, the condition assessment for Osullivan is currently listed as not available, highlighting the need for ongoing monitoring and maintenance to ensure its continued effectiveness.

Situated on the Lower Crab Creek, Osullivan serves as a key asset in the region's water resource management strategy. With its strategic location, impressive storage capacity, and multi-purpose design, this dam stands as a testament to the importance of sustainable water infrastructure in addressing the challenges posed by climate change and ensuring the long-term resilience of communities in Washington.