Panama No. 1 - Northwest, also known as Baller Lake or Swede Lake, is a private dam located in Boulder, Colorado. Built in 1904 for irrigation purposes, this rockfill dam stands at a height of 7 feet and stretches 1900 feet in length. With a storage capacity of 6979 acre-feet and a surface area of 370 acres, Panama No. 1 - Northwest plays a crucial role in water management in the region.

Managed by the Colorado Department of Water Resources, this dam on Boulder Creek-OS is regulated, inspected, and enforced to ensure its safety and functionality. Despite its low hazard potential and satisfactory condition assessment as of 2015, the dam is subject to moderate risk due to its age and the surrounding environment. With a maximum discharge of 4150 cubic feet per second and an uncontrolled spillway, Panama No. 1 - Northwest is a key structure in the water resource infrastructure of Colorado.

As a significant part of the water supply and irrigation system in the area, Panama No. 1 - Northwest not only serves practical purposes but also offers opportunities for recreation. With its historic background dating back over a century, this dam continues to be a vital component in managing water resources and adapting to the changing climate conditions in the region.