The Mill Creek Dam near Walla Walla, Washington has served its purpose admirably for over 67 years but according to a recent report by the US Army Corps of Engineers, the dam received a Dam Safety Action Category (DSAC) rating of 1 out of 5 which means that the risk to public safety is too great when Bennington lake which is formed by the dam is more than 17% full for an extended period of time. More after the break. (Photo by USACOE)
LANCASTER — Months of explosive blasting are expected to begin at the site of Center Hill Dam next week as the U.S. Army Corps of Engineers prepares to begin construction work at the aging dam in Lancaster.
"The blasting will be to excavate a platform for construction, about 40 feet wide and will look similar to a road cut through a hill," [Corps Project Manager Linda Adcock] said. "Just the nature of how we grout, and moving equipment back and forth on the current slopes, which are as much as 40 percent and greater, is just really difficult. So for these reasons, for safety, quality, the accuracy and the consistency of the drill holes are much better done from a platform, they proposed this road cut type of a platform."
The drilling is for grouting remediation of the dam foundation. Story from Herald-Citizen, Cookeville, Tennessee.
The Association of State Dam Safety Officials publishes monthly news items related to levee and dam safety and associated projects. Their April news items were just published this week and there are several interesting items. Read on for more info.
The San Diego County Water Authority board of directors last week certified the environmental impact report to raise San Vicente Dam by 117 ft.
The $568-million project, to be built on top of the existing San Vicente Dam in Lakeside, will expand the reservoir to hold an additional 52,000 acre-ft of water for use during emergencies and another 100,000 acre-ft of water to supplement imported supplies during dry periods.
The Dam will be constructed of roller compacted concrete and will reportedly be the largest dam raising ever performed in the US and the largest using roller compacted concrete in the world. (Photo by O’Connor Construction Management, Inc.)
An article in the Seattle Post Intelligencer discusses how the era of building massive dams that ended in the late 1960s with the completion of Glen Canyon Dam may be on its way to a resurgence because of booming populations throughout the west and a desperate need for water. This comes at a time when the USBR and other agencies are in the process of tearing down some dams. Of course the environmental hurdles and opposition to new dam projects will likely kill many of the projects before they get started. But in the absence of any kind of limits on population growth, there may not be many other options. Read on to see where major dam projects are being considered. (Photo by Molas)
On December 14, 2005, the upper reservoir of the Taum Sauk pumped storage plant, a hydroelectric power plant in the Missouri Ozarks, suffered a catastrophic failure. The resulting flood severely damaged the Jonhson’s Shut-Ins State Park and swept away the park superintendent and his family. Fortunately all of them survived. (Photos by Federal Energy Regulatory Commission and USGS)
Last week, the Missouri Attorney General’s office announced a settlement of $180 million between the facility’s owner, Ameren Corp. The failure reportedly was a result of negligence on the part of the company. More details after the break.
The Mosul Dam in Iraq is in danger of an "imminent collapse" according to a Washington Post article. The dam threatens the lives of as many as 500,000 people in Mosul which could be innundated by over 60-ft of water if the dam fails. Parts of Baghdad could see as much as 15-ft of water. Read on for more info.