Modern dams are much more than rock, gravel, and in the case of Chimney Hollow Reservoir, hydraulic asphaltic concrete. They hold instrumentation to make sure they remain safe and effective for decades to come. 

While building a modern structure that will hold water for hundreds of thousands of residents in Northern Colorado, the team at Chimney Hollow Reservoir is placing sensitive equipment and access points in the dam to measure many variables.  

Among those sensors are devices called piezometers (pronounced pi-ZOM-eters) that can detect water levels and possible seepage through and around the dam. All dams have seepage, and piezometers gather data to help dam engineers monitor the performance of the dam and underlying foundation.

Another device, a shape accel array, can detect real-time subtle movements in a dam to determine potential hazards. When Chimney Hollow Reservoir is full, more than 122 million tons of water will be pushing against the rock-fill dam. A shape accel array can detect how much flex occurs in the dam, and Northern Water engineers will compare those readings against expected performance of the embankment. 

As Chimney Hollow Reservoir moves toward completion, the placement of these safety features will play a critical role in keeping the state’s newest dam operating smoothly.