Who Builds Big? | Career Info Index | Engineering Webography
Andrew T. Straz is the Principal in charge of the Civil and Mechanical Engineering Group for E/PRO Engineering & Environmental Consulting in Augusta, Maine. He has been involved in a broad range of civil engineering activities related to the design, management, and construction of buildings, roads, bridges, and hydro projects over the past 28 years.
Check out a project that Andy worked on: Edwards Dam Removal, Augusta, Maine
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Yes, for as long as I can remember! As a young kid, I enjoyed playing with trucks and playing in the dirt. I was always interested in how things were built and how to take things apart -- even though I wasn't particularly good at it. I guess I just don't remember a time when I didn't want to be an engineer.
I went to the University of Maine at Orono and majored in civil engineering. It was kind of happenstance, really. I'm from Weymouth, Massachusetts, originally, and when I was looking at colleges, I happened to get a scholarship from the Society of American Military Engineers in Boston. I needed a school acceptance to get the scholarship, and I had one from Maine. The Society of American Military Engineers recommended it highly, so that's where I ended up.
I enrolled in a four-year civil engineering program, so I took math -- lots of math, physics, and chemistry the first year. As I progressed through the civil engineering ranks at the University of Maine, I had to make a decision as to what type of civil engineering program I wanted to be in. Structure has always interested me, so I chose the structural civil engineering program. But my career kind of led me through all kinds of things. I've really been a general engineer, in the civil sense. I've done just about everything.
I started out working for a steel fabricator where I did some small design work for steel structures. But really, I acted more as a project manager, making sure everything got done.
After working for the steel fabricator, I went to work for a small civil engineering consulting firm called Doten Associates here in Augusta, Maine. I spent eight years with them, and I did the structural design and the foundation work for small buildings. Basically, I analyzed buildings for large loads. The paper industry has something called a yankee dryer, which is part of the paper-making process. These dryers weigh hundreds of thousands of pounds, and to get them from a barge to the plant, they would have to go over certain bridges. I would analyze the bridges to make sure they could carry the heavy weight.
I got into dams in 1980 when I joined Central Maine Power. Central Maine Power owns 22 dams, and I've done work on all of them. I was primarily looking at the structural aspects of the dam. But I also did a lot of project management, pulling together all of the electrical engineers and outside consultants that we use, and making sure everything got done and the schedule was met and the budget was met. In 1999, a bunch of us at Central Maine Power got together, bought the engineering department, and formed our own engineering consulting firm, called E/PRO Engineering and Environmental Consulting. That's where I work today.
Yes! We removed the Edwards Dam on the Kennebec River in Augusta, Maine. It was the first hydroelectric dam in the United States removed despite opposition from the owner at the time.
Well, the process really started in 1983, when a lot of the hydroelectric dams on the Kennebec River became due for relicensing. The Edwards Dam was one of those licensees. Because the dam was only producing 0.1 percent of Maine's electrical power and there were many concerns about fish migration and passage at the dam, many local groups began to call for removal of the dam. Local support for removal was so strong that the federal government began to look at the removal of the Edwards Dam as an option.
There was a lot of concern about whether the steep reservoir embankments would slump into the river once the water level dropped. A lot of people -- who really hadn't been on the river -- envisioned massive mudslides and houses falling into the river if the dam was removed.
So the Federal Energy Regulatory Commission hired Stone & Webster, an engineering consulting firm, to study the entire river system and to develop an environmental impact statement regarding its removal. They also hired Oakridge National Laboratory to do an estimate of the removal of the dam. The Kennebec Coalition, an independent association of environmental groups, conducted its own study and came up with a substantially lower estimate for its removal. So the original studies had the dam coming out over a two- or three-year period, and the coalition ended up with a plan that took it out in one year. The savings was just dramatic. It went from a $10 million project down to what they envisioned was a $2 million project. The estimate wasn't far off. It actually ended up costing about $2.5 million.
Well, after the agreements on technical issues were established, we were hired by the state of Maine to actually remove of the dam. So our team had to develop a scheme to remove the dam. Nobody had ever submitted a dam removal plan before to the federal government. There were no guidelines. So we had to develop the whole process. I was the chief engineer for the project, the project manager.
We had originally planned to do a control demolition, a blasting, of a previously breached section in the middle of the dam. In order to remove or breach a dam, you need to divert the river while you're doing it. We do this with a temporary dam, called a cofferdam. But the Kennebec River is rather flashy. This means when it rains, the river comes up and goes over the top of the dam. To build a cofferdam high enough to prevent it from flooding becomes costly, and it becomes an economic balance of how high do you make the cofferdam, and how big do you make the breach in the dam, and how long is that going to take? It was too risky to have a cofferdam for what we thought would be an eight-week period. If the cofferdam overtopped and we didn't have all of the dam out, we wouldn't be able to rebuild the cofferdam. We'd have to start all over again.
We ended up not doing that because a contractor came in with a better idea: making a breach on the west shore.
The contractor, H.E. Sargent, Inc., believed that they could build a small cofferdam from the west shore and remove a section of the Edwards Dam in a few weeks. This reduced the risk involved with blasting a breach of just the right size and of overtopping an earth cofferdam left in the river for an extended period of time.
No, we didn't. There's some risk with the explosives. In fact, we had all kinds of offers. We had an offer from a special forces group to helicopter in and blow the dam up. We had all kinds of people who wanted to shoot it with a Howitzer cannon or a cruise missile.
Well, because of the concern of the embankments slipping in, we actually brought the dam down in two stages. In the first stage, we built essentially a couple-hundred-foot cofferdam from the west shore to the dam and then excavated out about 90 feet of dam. The dam is actually a timber crib -- a log structure filled with rocks -- with a concrete cap. On July 1, 1999, we breached the cofferdam. This breach lowered the reservoir behind the dam about eight feet.
We then moved over to the east side of the dam, built a smaller cofferdam over there, removed about 300 feet of dam on that east side. On August 12, 1999, we breached that cofferdam and lowered the pond the rest of the way, about five feet, which is quite a contrast from the July 1 one, where there were thousands of people watching and all this hoopla. On the 12th, I think there were five of us there, and one small local TV crew who stayed about five minutes. Then it was all over.
I've had some calls from other engineering firms asking how we went about this or that. I've also had inquiries from other people who are taking dams out. But we haven't undertaken another project.
Yes! Concentrate on math, science, and writing courses. You could be the greatest engineer in the world, but if you can't convey your ideas to somebody else, it's useless. Your ability to communicate your ideas to somebody else becomes a big part of what you're doing. It was lacking in me originally, and it's something that I think all engineers have to develop. Even though you're going to be a technical person, you need to have the writing background to be able to communicate your ideas to other people.
Physics. I liked the problem-solving, hands-on nature of physics.
I like to hike and fish. I also canoe with my family a lot. In fact, my family and I went down the Kennebec River in May prior to the Edwards Dam removal. Then we did it again after the dam removal just to see the effects of the breach. We've seen a dramatic change in the fish population in the river.