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| Oldman River Dam spillway, May 17, 2014 C. Davis photos/video |
An open house was held at the Oldman Dam on Thursday evening May 15. Several information sessions were presented to interested members of the public. I attended the first of these. Oldman Basin Operations Manager Terrence Lazarus presented information about how the dam is operated, its purpose, and its role in flood mitigation. Once his main presentation was concluded it became evident that some in attendance were there with a purpose, specifically to question whether last June's flooding event could have been better handled.
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| Oldman Basin Operations Manager Terrence Lazarus |
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| Dave Ardell, Director, Alberta Water Management Operations |
Lazarus began his presentation with a dissertation on the importance of snow-pack to the dam's operation.
"Think about it," he said. "You have flooding in May but the most sustainable source of water is snow melt. Without this, we may not be able to live (here). There wouldn't be enough water. The snow melts generally in March, and finishes about in the early part of June. Not this year (2013) of course, that was a spectacularly unusual year."
"It's the snow high in the mountains that sustains the rivers right through the year."
According to Lazarus, on average snow melt contributes 85% of the dam's flow. "That's like money in the bank.”
"If you look at rain, rain comes later, and over less (time). Often, the end of May, beginning of June, it rains."
Lazarus also talked about the role of snow pack measuring stations in the dam management process, and how different elevations melting at different times affects the process of predicting water levels.
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| Oldman Dam spillway, May 15, 2014 |
"You get cold wet loads that form off of the Aleutian Islands," Lazarus said. Those loads move with the jet stream, and sink down as summer approaches. Air pressure changes in the arctic and at the equator. "They are pushed by the prevailing winds, they then move easterly. What often happens, and it happens in June, it also gets very hot in the Gulf of Mexico."
"So you get a cold, wet pressure swirling just like a hurricane, and it pulls up this warm air and they meet, guess where? In Alberta."
"That thing can hit anywhere in Alberta," he said, causing "Intense, intense rain."
"Other ways it rains in Alberta in the summer is convection."
"These mechanisms are our greatest flooding mechanisms in the area."
"Why do we have reservoirs? I think that is a legitimate question. Quite simply, it is because we need to save water."
"If you look at evaporation, we get 500 milliliters coming down, and 800 going up, I think you can do the math, right? It's dry. In this Oldman Valley between BC and Saskatchewan, there's about 250,000 people. Farming, agriculture, industry and we live here. All four require water. We require sustainable, secure water."
"The other part of this equation is that this is some of the best agricultural land in the country. We have suffered from a lot of droughts here, and they come in very long cycles. We know that. And it can come quite quickly. The spring is wet, and suddenly, we have a drought."
"Most of you wonder what do I do, what does my staff do, how do we operate, why do we operate," Lazarus continued, referring to a graphical demonstration of a reservoir. "This schematic is this reservoir. You have to pick a reservoir that is in a steep valley to store water. You know that, all dams are in big valleys. This is the bottom of the reservoir, and this is the top of the reservoir. So think of that green area as volume."
"The simple story of that is all the storage of the water is in the top, not the bottom. It's about volume, not height."
"We don't just haphazardly fill reservoirs. We need a plan, and the plan there is a fill-curve. The fill-curve is risk management. Like everything in life, we have to manage our resources."
According to Lazarus, by measuring to the top of the curve "you have a reasonable chance of dealing with any flood, and assure that you are going to fill the reservoir."
"Our primary purpose is to fill the reservoir. Because that is what we spent a million, billion dollars on, is to have storage of that water supply. We monitor the situation, we see what is happening, we don't divorce ourselves from the outside world."
"Right now, we know that there's a lot of snow. And it makes our life really difficult because right now it is May the 15th, and the snow only started melting more or less yesterday. So now we have to make decisions about where we are in this curve. What should we do? How are we going to handle this?"
"We have to deal with statistics, what the average is, what we might reasonable expect. These two red lines are the range of where we normally go. Winters, we can be all over the place. Most years, we don't fill the reservoir, because we try to fill it conservatively. Where we are, between those lines, is were we are most, fifty percent of the time.
Lazarus then discussed two exceptional weather events, the flood of 1995 and the flood of 2013.
"I had a week of sleepless night in 1995," he said. "If we look at 1995, this green line is the volume that came in. It reached nearly 3,500 cubic metres per second. From beginning to end was 12 hours." He said that volume was not forecast. "The red line is what we released. We dropped that peak by about 10%.
"Of course, there comes the pain. There's a volume in the flood that you can't remove. As much as you reduce the flood, then you have got to deal with it afterwards. We reduced that peak by about 10%, and delayed it by about 4 hours."
"Just go to look at the reservoir level. If it goes up, it means that less went up than came in. It's very simple math, if you can't get rid of the water. You need to look at a reservoir level to say did they create a flood, or reduce it? The answer is in the elevation of the reservoir."
At this point a woman in the crowd, Maryanne Sandberg, interjected. "In 1995, it rained for a good week, week and a half before they opened those gates, and I can tell you that my husband had been phoning prior to that, when it started to rain. We were asked questions, and asked questions. The morning that they opened the gates, he was told please, this is like nothing you have ever seen in your lifetime is coming. He said thank you very much, at the last minute. People phoned and offered their advice, people who have lived on the river all their life, and they see the rain, and they see the snow pack and they ask questions and their is no courtesy given back. That was in 95."
Lazarus assured her he would address her concern when he was finished his presentation.
"I am just going to do some stats on 2013," he said. "The time of 2013 lasted 36 hours. during that time (2,000 cubic metres of rain fell). That is a phenomenal amount in an incredibly short period of time. In one hour, the inflow was increased by 430 cubic metres an hour." Picture enough water to serve the Lethbridge region for one year, in one hour.
"Our primary purpose is to fill the reservoir. Because that is what we spent a million, billion dollars on, is to have storage of that water supply. We monitor the situation, we see what is happening, we don't divorce ourselves from the outside world."
"Right now, we know that there's a lot of snow. And it makes our life really difficult because right now it is May the 15th, and the snow only started melting more or less yesterday. So now we have to make decisions about where we are in this curve. What should we do? How are we going to handle this?"
"We have to deal with statistics, what the average is, what we might reasonable expect. These two red lines are the range of where we normally go. Winters, we can be all over the place. Most years, we don't fill the reservoir, because we try to fill it conservatively. Where we are, between those lines, is were we are most, fifty percent of the time.
Lazarus then discussed two exceptional weather events, the flood of 1995 and the flood of 2013.
"I had a week of sleepless night in 1995," he said. "If we look at 1995, this green line is the volume that came in. It reached nearly 3,500 cubic metres per second. From beginning to end was 12 hours." He said that volume was not forecast. "The red line is what we released. We dropped that peak by about 10%.
"Of course, there comes the pain. There's a volume in the flood that you can't remove. As much as you reduce the flood, then you have got to deal with it afterwards. We reduced that peak by about 10%, and delayed it by about 4 hours."
"Just go to look at the reservoir level. If it goes up, it means that less went up than came in. It's very simple math, if you can't get rid of the water. You need to look at a reservoir level to say did they create a flood, or reduce it? The answer is in the elevation of the reservoir."
At this point a woman in the crowd, Maryanne Sandberg, interjected. "In 1995, it rained for a good week, week and a half before they opened those gates, and I can tell you that my husband had been phoning prior to that, when it started to rain. We were asked questions, and asked questions. The morning that they opened the gates, he was told please, this is like nothing you have ever seen in your lifetime is coming. He said thank you very much, at the last minute. People phoned and offered their advice, people who have lived on the river all their life, and they see the rain, and they see the snow pack and they ask questions and their is no courtesy given back. That was in 95."
Lazarus assured her he would address her concern when he was finished his presentation.
"I am just going to do some stats on 2013," he said. "The time of 2013 lasted 36 hours. during that time (2,000 cubic metres of rain fell). That is a phenomenal amount in an incredibly short period of time. In one hour, the inflow was increased by 430 cubic metres an hour." Picture enough water to serve the Lethbridge region for one year, in one hour.
With that Terrance Lazarus opened the floor to questions.
"I know there is a lot of angst," he said. "I don't know what all the answers are. I know that people think I operate alone, I suspect you might be in left field. What is the right way?"
Maryanne Sandberg was the first to respond. She is the Division 3 councillor for the MD of Willow Creek, but afterwards told me she was speaking as a private citizen. "I guess communication is the key, and I think everyone feels that way. And I appreciate that the government is coming out with some form of communication. I feel it has to be better done. There has to be more communication of some kind, or better relationships between the MDs, and get the message out to people in correct ways. I'm not sure how to address it, but communication is absolutely key. The correct communication, of the correct data, at the appropriate times."
"You understand of course that we operate dams, we are not an Emergency Management Agency," responded Lazarus. "We work very closely with them, we are not divorced from them, we work together."
"That's what we see, as people who live downstream.," said Sandberg. "You know that you're going to flood. When you open those gates, and we live, you know, Fort Mcleod, so lets say four hours (away), we just think that someone should tell us that you are going to flood us."
"Alberta is set up with very clear definitions of emergency management," responded Lazarus. "We communicate with a group called flow forecasting, who are in direct, constant contact with local authorities. So they have the information of what is going to happen, when it happens. Local authorities are designated to look after the residents in an area."
"What I suspect you are saying is that 'you are constantly make mistakes', but that's not true. We learn by mistakes, and we have been adjusting our systems, and trying to improve. These things come at us very fast, very hard. And it's a two way street. We assume that everyone knows that June is going to flood, and they have preparations for that."
"If you own property right next a river, you have a lot a of benefit from that. Part of your personal responsibility is being prepared."
"As rural people, many of us are farmers and ranchers," said Sandberg. "Many of us don't have homes down there, but we do have property in the small 'p' sense. Irrigation sites, irrigation pumps with cattle, but it is the loss of property. My mother in law was there and saw the floods in 50, a huge flood. My family has been there for 76 years on that land." Sandberg also mentioned neighbours who have lived in the area longer than that. "They have seen floods, prior to the dam, and they've seen big floods. The damage that is done to the riverbanks, erosion, loss of land since 95 in some cases for people is huge, but the erosion that is done from the sudden release of water from there..."
"We are currently spending a lot of money, trying to relocate a pump site. How many years do we have to keep doing that? The irony is that there is some big money being spent in the cites, What do rural people get for help? We can't even go in the river because this part of the environment is so strong. You can't touch the fishies, you know. The flood could cause more damage and create more hazard for the fish population than we can to go in and protect our own property. There are people with houses too, that in rural areas that are not even getting help to relocate by this government, because of what damage was done from the water that was released for them."
"As you well know, I cannot speak for the government," replied Lazarus.
"That's the problem," retorted Sandberg. "Who can help us? If a dam operator can't even communicate that, and help us out, then where to we go?"
"I can say that the local authorities have the responsibility of working with the locals in any kind of rural community." responded Jacob Modayil, a representative of the Government of Alberta’s new Resilience and Mitigation branch.* "The MD is the right place to go."
"I am an MD Councillor, and I can't even get our own MD to touch it" replied Sandberg. "Look at High River, they fixed the highway, but they won't touch ours."
Another man in the audience also had questions. "When you know what the snow pack up is up there, and you know that at some point in a given time we are going to get spring rains, why is the dam so full? Or we perceive that it is full at the time. Right now, apparently, it's quite low. So the learning has been it's probably good to be low? Is that the idea? Was there a process of learning this? Let me clarify: 1995 it was a year after the dam, maybe there had to be a learning, but last year I wondered whether or not it was too full..."
"I spend, between now and June 18 hours a day thinking and looking and working at this stuff" replied Lazarus. "Earlier in this presentation we talked about snow melt. Understand that snow melt does not contribute to flooding. Snow melt is a guarantee, rain is not. If you know for sure that it is going to rain you need to tell me the winning lotto 649 numbers. We have to work on what we know. '95 is a good example. The snow had melted, it was extreme rainfall. Guess what? In the mountains it didn't fall as rain, it fell as snow, so that did not contribute to that (event)."
Several others in the audience expressed the opinion that the reservoir was too full prior to the flooding event last June. A citizen who lives upstream of the dam, took issue with the idea that management of the dam was to blame for downstream flooding. He said the river was overflowing "before it ever got to the dam, so the rivers were totally out of control before they got here.That had nothing to do with the dam, and it took a lot of my property out. The Oldman River was mad."
"I think we've had enough of the public flogging," said Lazarus. "There is no such thing as average. We simply don't know how much rain will come in June. We live in southern Alberta. This has some of the most extreme climactic conditions in the world. We know that, I don't have to tell you. And climactic conditions include rainfall. It's extreme, and it can be all over the place."
According to Lazarus, the dam held back more water than it let go, actually decreasing downstream flooding by doing so.*
Video - June 2013 weather event at Oldman Dam and surrounding area:
"I know there is a lot of angst," he said. "I don't know what all the answers are. I know that people think I operate alone, I suspect you might be in left field. What is the right way?"
Maryanne Sandberg was the first to respond. She is the Division 3 councillor for the MD of Willow Creek, but afterwards told me she was speaking as a private citizen. "I guess communication is the key, and I think everyone feels that way. And I appreciate that the government is coming out with some form of communication. I feel it has to be better done. There has to be more communication of some kind, or better relationships between the MDs, and get the message out to people in correct ways. I'm not sure how to address it, but communication is absolutely key. The correct communication, of the correct data, at the appropriate times."
"You understand of course that we operate dams, we are not an Emergency Management Agency," responded Lazarus. "We work very closely with them, we are not divorced from them, we work together."
"That's what we see, as people who live downstream.," said Sandberg. "You know that you're going to flood. When you open those gates, and we live, you know, Fort Mcleod, so lets say four hours (away), we just think that someone should tell us that you are going to flood us."
"Alberta is set up with very clear definitions of emergency management," responded Lazarus. "We communicate with a group called flow forecasting, who are in direct, constant contact with local authorities. So they have the information of what is going to happen, when it happens. Local authorities are designated to look after the residents in an area."
"What I suspect you are saying is that 'you are constantly make mistakes', but that's not true. We learn by mistakes, and we have been adjusting our systems, and trying to improve. These things come at us very fast, very hard. And it's a two way street. We assume that everyone knows that June is going to flood, and they have preparations for that."
"If you own property right next a river, you have a lot a of benefit from that. Part of your personal responsibility is being prepared."
"As rural people, many of us are farmers and ranchers," said Sandberg. "Many of us don't have homes down there, but we do have property in the small 'p' sense. Irrigation sites, irrigation pumps with cattle, but it is the loss of property. My mother in law was there and saw the floods in 50, a huge flood. My family has been there for 76 years on that land." Sandberg also mentioned neighbours who have lived in the area longer than that. "They have seen floods, prior to the dam, and they've seen big floods. The damage that is done to the riverbanks, erosion, loss of land since 95 in some cases for people is huge, but the erosion that is done from the sudden release of water from there..."
"We are currently spending a lot of money, trying to relocate a pump site. How many years do we have to keep doing that? The irony is that there is some big money being spent in the cites, What do rural people get for help? We can't even go in the river because this part of the environment is so strong. You can't touch the fishies, you know. The flood could cause more damage and create more hazard for the fish population than we can to go in and protect our own property. There are people with houses too, that in rural areas that are not even getting help to relocate by this government, because of what damage was done from the water that was released for them."
"As you well know, I cannot speak for the government," replied Lazarus.
"That's the problem," retorted Sandberg. "Who can help us? If a dam operator can't even communicate that, and help us out, then where to we go?"
"I can say that the local authorities have the responsibility of working with the locals in any kind of rural community." responded Jacob Modayil, a representative of the Government of Alberta’s new Resilience and Mitigation branch.* "The MD is the right place to go."
"I am an MD Councillor, and I can't even get our own MD to touch it" replied Sandberg. "Look at High River, they fixed the highway, but they won't touch ours."
Another man in the audience also had questions. "When you know what the snow pack up is up there, and you know that at some point in a given time we are going to get spring rains, why is the dam so full? Or we perceive that it is full at the time. Right now, apparently, it's quite low. So the learning has been it's probably good to be low? Is that the idea? Was there a process of learning this? Let me clarify: 1995 it was a year after the dam, maybe there had to be a learning, but last year I wondered whether or not it was too full..."
"I spend, between now and June 18 hours a day thinking and looking and working at this stuff" replied Lazarus. "Earlier in this presentation we talked about snow melt. Understand that snow melt does not contribute to flooding. Snow melt is a guarantee, rain is not. If you know for sure that it is going to rain you need to tell me the winning lotto 649 numbers. We have to work on what we know. '95 is a good example. The snow had melted, it was extreme rainfall. Guess what? In the mountains it didn't fall as rain, it fell as snow, so that did not contribute to that (event)."
Several others in the audience expressed the opinion that the reservoir was too full prior to the flooding event last June. A citizen who lives upstream of the dam, took issue with the idea that management of the dam was to blame for downstream flooding. He said the river was overflowing "before it ever got to the dam, so the rivers were totally out of control before they got here.That had nothing to do with the dam, and it took a lot of my property out. The Oldman River was mad."
"I think we've had enough of the public flogging," said Lazarus. "There is no such thing as average. We simply don't know how much rain will come in June. We live in southern Alberta. This has some of the most extreme climactic conditions in the world. We know that, I don't have to tell you. And climactic conditions include rainfall. It's extreme, and it can be all over the place."
According to Lazarus, the dam held back more water than it let go, actually decreasing downstream flooding by doing so.*
Video - June 2013 weather event at Oldman Dam and surrounding area:
*updated with extra information
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