Dd No 30 is a rockfill dam located in Brown County, Kansas, with a primary purpose that is currently unspecified. The dam stands at a height of 39.7 feet and has a length of 813 feet, providing a storage capacity of 490 acre-feet. Despite its low hazard potential and moderate risk assessment rating, the dam has not been rated for its condition as of the last inspection in 2011.

Managed by the Kansas Department of Agriculture, Dd No 30 is subject to state regulation, permitting, inspection, and enforcement. The dam sits on an unnamed tributary and is part of the Rock Island District within the state. Although the dam does not have associated locks, gates, or spillways, it does have a maximum discharge capacity of 4,776 cubic feet per second. With a surface area of 12 acres and a drainage area of 1.46 square miles, the dam serves as a vital infrastructure for water resource management in the region.

Designed by King Engineering, Dd No 30 remains a crucial part of the local government's water resource infrastructure. With its structural integrity and low hazard potential, the dam plays a significant role in mitigating flood risks and managing water supply in the area. As climate change continues to impact water resources, the proper maintenance and assessment of dams like Dd No 30 are essential for ensuring the safety and sustainability of water infrastructure for future generations.