Mirror Pond will drop even lower this week

Photos by Rob Kerr / The Bulletin

Starting Monday, the company that owns Newport Avenue Dam will lower the water level a couple of inches per hour until it is low enough to investigate a recently discovered leak in the dam.

What's happened

PacifiCorp discovered a leak in the dam Oct. 2, and Mirror Pond dropped by roughly 2 feet in the days that followed, turning much of the area into mudflats. The pond then rebounded briefly as water managers upstream adjusted flows in the Deschutes River to prepare for the end of irrigation season. The water level has since receded a second time, stabilizing around 2 feet below its typical winter level.

What's happening now

PacifiCorp plans to draw down the water even further starting Monday, to get a better look at the damaged area. How far the water will drop this week is unclear; workers will lower it until they can get a good look at the problem. The drawdown will likely take two to three days.

What needs to be done

Though the inspection is this week, any repairs to the dam will probably happen later, which could mean water levels fall for a fourth time. In the past, dam operators have found and repaired three seemingly similar leaks in the last five years by bolting large sheets of metal to the more than 100-year-old wooden dam.

One pond, two views

This is how Mirror Pond looked in March in a satellite photo taken when its level was approximately 2 feet higher. The silt buildup that is at the heart of the debate of whether to dredge Mirror Pond, partially dredge it, remove the dam and let the river run its natural course, or do nothing.

Contrast the March photo with aerial photos of the river as it is today.

PacifiCorp plans to draw down the water even further starting Monday, to get a better look at the damaged area. How far the water will drop this week is unclear; workers will lower it until they can get a good look at the problem. The drawdown will likely take two to three days.
This is how Mirror Pond looked in March in a satellite photo taken when its level was approximately 2 feet higher.
Contrast the March photo with aerial photos of the river as it is today.
This aerial photo taken Friday faces west; Mirror Pond - with its exposed mudflats - is pictured on the left. To the right of Newport Avenue, you can see the gush of water from the dam leak.
PacifiCorp discovered a leak in the dam Oct. 2, and Mirror Pond dropped by roughly 2 feet in the days that followed, turning much of the area into mudflats.
Looking straight down on the river gives an idea of the natural banks of the river and the depth before this week's drawdown begins. How low it'll go will be determined by the depth workers need to get a good look at the leak.
Contrast the March photo with aerial photos of the river as it is today.