Ethiopia is in the midst of a major nation-building project, constructing the Grand Ethiopian Renaissance Dam (GERD). Upon completion, GERD will become the largest hydropower plant in Africa, providing much needed electricity for the country’s growing population.
The project dams the Blue Nile, a river which later flows into neighbouring Sudan, where it merges with the White Nile and then flows on to Egypt. Like all rivers that flow across political boundaries, concerns have been raised about the equitable management of the water resources to the benefit of those upstream and down. Too much water dammed upstream in GERD could have negative effects on Egyptian agriculture reliant on river flows, for example. Efforts are ongoing to find a peaceful solution that suits all parties. Recently, suggestions have been made to supplement the dam’s power output with solar and wind to minimise disruption to the river’s users.
Continue reading “Solar And Wind Could Help Support Ethiopia’s Grand Dam Project”
More than two years ago, the largest dam in the United States experienced a catastrophic failure of its main spillway, the primary means by which operators of the dam prevent the lake from cresting its pen. The spillway failure caused so much erosion that the hydroelectric plant could not operate, further worsening the situation. In a few days, the dam was finally put to its design limitations, and water began flowing down an emergency spillway that had never been used, prompting the evacuation of 188,000 people living in downstream communities.
Since the time that this crisis came to a head, crews have been working around the clock to repair the main and emergency spillways in order to ensure that one of the largest pieces of infrastructure in the wealthiest country in the world does not suffer a complete failure. The dam’s spillways were reopened recently on April 2, in time for this year’s snow melting, and so far everything looks good.
The repair work was a true feat of engineering, and perhaps a logistics miracle as well. The video below goes over a lot of the raw materials inputs that were needed, but the one that stuck out the most was that a dump truck full of roller-compacted concrete was emptied every five minutes over the entire course of the repair — enough to build a sidewalk from the Oroville Dam to Texas. Part of the reason for the use of such an incredible amount of concrete was that it wasn’t just used to repair the main spillway. An enormous “splash pad” for the emergency spillway was also constructed to limit erosion in the event that it must be used again. But the full change goes beyond concrete and rebar. Join me after the break as I try to wrap my mind around the full scope of the Oroville Dam repair.
Continue reading “Repairing A Catastrophic Failure: The Oroville Dam Update”
Infrastructure seems so permanent and mundane that most of us never give it a second thought. Maintenance doesn’t make for a flashy news story, but you will frequently find a nagging story on the inside pages of the news cycle discussing the slowly degrading, crumbling infrastructure in the United States.
If not given proper attention, it’s easy for these structures to fall into a state of disrepair until one suddenly, and often catastrophically, fails. We’ve already looked at a precarious dam situation currently playing out in California, and although engineers have that situation under control for now, other times we haven’t been so lucky. Today we’ll delve into a couple of notable catastrophic failures and how they might be avoided in future designs.
Gaining Weight While Delaying Repairs
Most of us take infrastructure for granted every day. Power lines, roads, pipelines, and everything else have a sense of permanence and banality that can’t be easily shaken. Sadly, this reality shattered for most people in Minneapolis, Minnesota in August 2007.
Continue reading “Failing Infrastructure And The Lessons It Teaches”