Green Mountain Spillway Upgrades Finished Early

Northern Water and the Bureau of Reclamation together found a silver lining within this year’s devastating drought, taking advantage of historically low water levels to complete a needed project ahead of schedule, with fewer operational disruptions and at a lower cost.  

The scarce supplies in Green Mountain Reservoir have created their share of challenges, but the depleted water levels also provided unexpected easy access to the bottom of the dam’s spillway. That allowed crews to replace the concrete apron along the floor of the structure and make other associated repairs to the approach section of the spillway, which is now more than 80 years old. 

This critical work wasn’t initially slated to take place until 2028, before this year’s low water levels created an opportunity. The project was also completed with fewer operational complications due to the naturally low water levels, rather than requiring some of the extensively coordinated steps typically needed to dewater a work site within a reservoir.  

The combination of easier access to the site, fewer operational complications, and being done ahead of schedule all helped the cost of the project come in lower than expected, at about $1.25 million.   

The Green Mountain Reservoir work took place from August to October. That followed Northern Water and Reclamation’s efforts this summer at Shadow Mountain Reservoir, where crews for a second consecutive year replaced portions of the concrete floor along the dam’s spillway.