Mr. BAKER. In our country, it is called a crown corporation, Mr. Chairman. It is owned by the government of Nova Scotia. And it has substantial objectives, the exploitation of the tidal resource. And it has in the legal sense, all the rights and obligations of any other corporation formed under the law.

Senator MITCHELL. The reason I raise the question of jobs during construction is that in this country, at least, one of the perceived benefits in large projects such as this particular hydroelectric project is, of course, the creation of jobs during the construction period, both in terms of onsite construction and provision of materials such as, in this case, the turbines required by the project. Ordinarily, of course, I am certain that is a factor in the minds of the Nova Scotian government.

Mr. BAKER. Undoubtedly.

Senator MITCHELL. Unemployment being what it is there as well as in the United States. And ordinarily, of course, it would be expected that the benefits would flow to the area or the country in which it is being constructed. You have, however, here an unusual case in which, according to your own study, 90 percent of the power will be exported to the United States, and American participation will be essential if the project is to go forward. Under such circumstances, it seems to me it would make sense, at least to present the opportunity to discuss the prospect of American participation in a more direct and immediate

sense.

Mr. BAKER. Yes, Mr. Chairman. I guess my only additional comment on that would be come what may. If the project were to go ahead, it would have perhaps a half billion dollars' worth of line construction work to be done entirely in the States. There would be a good deal of need for technical design services, managerial services and a lot of those come from the need of the United States. The onsite construction, I think it might be rather out of the question on account of logistics to make any U.S. procurement, and I have already mentioned the turbines.

Senator MITCHELL. Right. Mr. Baker, I thank you. I want to conclude by saying that I welcome your attitude toward an assessment of the potential environmental impacts, and specifically your proposal for a joint United States-Canadian entity to participate in that assessment. That is very important to us, and I expect to follow through with you on that, both personally and along with other American officials to try to develop the entity, or select or develop an entity, that will be most suited to that task, and that gives us some reassurance that we will play a direct and meaningful role in that assessment and in the evaluation of the assessment. That is very important to us. Mr. BAKER. Thank you very much.

Senator MITCHELL. Thank you very much, Mr. Baker, for coming. Your full statement, Mr. Baker, will go into the record as I indicated earlier.

Our next witness is Dr. David Greenberg of the Bedford Institute of Oceanography. Doctor Greenberg, we welcome you. We are aware of the work you have been doing with respect to this subject, and we look forward to your testimony.

STATEMENT OF DR. DAVID A. GREENBERG, BEDFORD

INSTITUTE OF OCEANOGRAPHY

Dr. GREENBERG. I think I better perhaps begin with the usual civil service caveat that the opinions that I will be expressing are my own rather than those of my employer, the Government. And also that my specialty is a rather narrow part of physical oceanography, but the nature of what I have done spills into a lot of other fields, and I will try to make it clear when I am stepping outside and making more tentative conclusions than those I am very familiar with.

The initial goal of this work was to predict the tide at a tidal power barrier to figure out what power would be available from a barrier, and that would work its way into the economically feasibility, economic viability of the scheme. And we ended with a second goal that the same work might be useful in determining environmental impacts both around the barrier and how far away from the barrier they might occur. The technique used was one of computer modeling, and it is now a very well tool. It is used in such places as Jamaica Bay by the Rand Corp. in their studies of pollution. The British are using it in the north seas to study storm surges to figure out when they are going to close their Tens barrier to keep from flooding London, and the Dutch are using it extensively in their government projects for dyking of the lowlands.

Our Bay of Fundy-Gulf of Maine studies gives perhaps some surprising results when you first look at them. They indicate a tidal power barrier at the head of the Bay of Fundy would change the tides throughout the Bay of Fundy and the Gulf of Maine. Three dams are contemplated. George Baker talked about two. The third and less economically viable, the two smaller schemes one which he denoted A-8 across Cumberland Basin in Chignecto Bay and another beside it up across Shepody Bay both in Chignecto Bay had very similar type changes. They would cause a drop in the tidal amplitude; that is to say, the high tide would be lower and low tide would be higher so you would end up with a smaller tidal range. Due to these areas at the barrier site and throughout the head of the bay, that decrease would disappear around the central part of the bay and as you got to the mouth of the bay, you would start to see an increase, and that increase would exist throughout the Gulf of Maine. For these small schemes, we're talking perhaps at a 2-inch higher high water, 2-inch lower low water effect throughout the coastline and Gulf of Maine.

Senator MITCHELL. Do I understand that you are saying that in the immediate vicinity of the dam, high tide would be higher or lower? Dr. GREENBERG. High tide would be lower.

Senator MITCHELL. High tide would be lower. Low tide would be higher. That is getting away from that on the coast of Maine, those effects would be reversed?

Dr. GREENBERG. That's correct.

Senator MITCHELL. I see.

Dr. GREENBERG. The larger of the three schemes, the B-9 scheme, the one at Economy Point in Minas Basin could give rise to a drop at the barrier in the very near vicinity of the barrier but other than that,

throughout the head of the Bay of Fundy and throughout the Gulf of Maine, we would see an increase in tide; and that increase could be as high as 8 or 9 inches in the upper Bay of Fundy. That is 8 or 9 inches higher high water; 8 or 9 inches lower low water. That decreases slightly-increasing slightly to say around Boston, we can still see 6-inch increases in high water, decrease in low water.

In all three cases, the effects tend to disappear as you round the corner of Cape Cod and get by Hyannis. Or as you round the Cape stable and start to work up the Nova Scotia coast.

Superficially, these changes seem a little far fetched, and we wonder how a dam a couple of miles long could effect the tides hundreds of miles away, and we wonder if we can really believe this. We think we

can.

I will put forward three of the reasons that go into our thinking. The first is we have put the model through an awful lot of testing and upgrading, and we keep on getting very similar answers. Some of the quantity of answers, the exact answers have changed or been modified as we go to better and better schemes. But they always predict the same sort of thing with a drop at the barrier and an increase for erosion.

Second of all, there have been two independent researchers who got the same sort of answers with different but not as well calibrated or much coarser models. That is to say, they are seeing decreases at a power tidal barrier and increases throughout the Gulf of Maine. One of these studies addressed a very different sort of problem but was able to give the same sort of result and another study which was a very courser type model.

And the third reason that I think we can believe this. We can explain physically what is happening, and the physical phenomenon is that of resonance if I can go to an analogy. If we sit in the bathroom and rock back and forth at the right sort of frequency, with almost no energy at all you can pump the water right over the ends of the bathtub. If you go the wrong frequency, you end up with a bunch of waves in the bathtub. The Bay of Fundy and the Gulf of Maine might be considered as one bathtub and the rocking is taking place at the edge of the Continental Shelf, and that is what is driving the tides in that area. The right period for the Bay of Fundy in the Gulf of Maine is about 13 hours, the tides are rocking it back and forth at about 121 hours. That is not exact, but it is close enough to give the very high tides that we find in the Bay of Fundy now.

Senator MITCHELL. Could you explain again the relationship of the two times you just stated?

Mr. GREENBERG. The 13 hours is the period that the Bay of Fundy by itself would naturally oscillate. The period that it responds most, the Bay of Fundy and Gulf of Maine system responds most at a period. It doesn't take very much energy to get a vary large output of energy at that frequency.

Senator MITCHELL. What occurs every 13 hours.

Mr. GREENBERG. Naturally nothing. It is like a swing hanging there with somebody on it. You need somebody to push it. If you push it at the right frequency, then it is easy to keep pushing it to get it higher and higher. If you try to push it not at the frequency at which it would

naturally swing, then you end up with a disjointed, jerky sort of swing.

Senator MITCHELL. But where do the 13 hours come from?

Dr. GREENBERG. The 13 hours come from an analysis, one of the previous studies that I have mentioned briefly that suggests that is the right period for the Gulf of Maine. Actually, there are two studies where they have analyzed the available tidal data, and there are different frequencies hitting it, not just the 1212-hour data. And when you look at the response to the difference frequencies, you can say, OK, this is peaking at 13 hours. This is where the Bay of Fundy-Gulf of Maine would most fully respond.

Senator MITCHELL. Well, I understand the 1212-hour period. There is a physical event that is associated with that. I am trying to understand what physical event occurs within the 13-hour period.

Dr. GREENBERG. There is no physical event that occurs in the 13-hour period. That is, as I say, like a swing sitting there all by itself with somebody on it. And you could calculate like a pendulum what the right frequency or period of that pendulum is the same way as a clock swinging back and forth at a constant second per back and forth. Senator MITCHELL. And is it the close proximity of those two figures in time that leads to the pronounced effects that would be felt here?

Dr. GREENBERG. Yes. It first of all leads to the high tides we see in the first place. And by chopping off the end of the bay, we are pushing that 13 hours even closer to the 121⁄2 hours, and that is why we see the whole system respond. So the effect is because the whole system is moved a little bit closer.

Now, it is more complex than just a simple swing or just a simple bathtub, so there are more effects. We see the drop at the head of the bay and the other things that get involved, but the overall effect in the full system is because we are moving the whole system closer to the tide.

Senator MITCHELL. You are saying that there are two independent time periods which happen to closely coincide and which therefore in conjunction cause a very pronounced effect with an already existing pronounced effect that would be made even more pronounced by the construction of the dam which would shorten the bay?

Dr. GREENBERG. That's correct.

Senator MITCHELL. Thank you. Continue.

Dr. GREENBERG. OK. I guess the next question is, how significant are these changes, the 2 and 6 inches added on top of the tide? If we look at one extreme, and we forget about anything the weather can do to you, we can say that the tides are very variable by themselves. And if we take perhaps the example of Boston, because everybody likes to think of closing Logan Airport every high water, we can say that they have an average tide of about 9 feet. But over the course of a year, the lowest tidal range would be about 6 feet, and the highest tidal range would be somewhere around 12 feet. We, at 6 inches to high and low water in each case, we are changing that tidal range to 7 to 13 feet instead of 6 to 12 feet. And so most of the time, the new tidal ranges that you see from tidal power are within the ranges that are already seen in nature today.

If we now add what weather does to the water levels, there can be storm surges that will change the water levels by up to 5 or 7 feet from

the predicted astronomical tide from bad storms, and we have incidence of those in the upper Bay of Fundy as well as incidences down here. Add to that any kind of wave activity in 6 inches seems absolutely negligible, but that is entirely the wrong way to look at it as it stands. Superficially, you might not see it every time, but it would be there.

If you look at another extreme, if we define the usable property along a shore as somebody owning his property up to the high waterline and if we say a beach slope is somewhere about a 1-foot rise for every 40 feet inland and that is a low beach slope, then a 6-inch rise in high water would take 20 feet off the beach frontage of a property. If we could multiply that by the length of Cape Cod times the cost of an acre in Cape Cod, we would end up with a fairly large number, I think. But again I think that is a rather extreme view.

Senator MITCHELL. Big compensation, Mr. Baker.

Dr. GREENBERG. Some of us don't make that much in 1 week. I think it is more accurate to say that the areas that are already sensitive to high water now would be the ones that are most at risk, and anything that is not senitive at all to high water now might end up with a marginal risk.

We have already mentioned areas with low beach slope. That might include things like salt marshes which depend on occasional floodings by the higher high waters or the storms to change nutrients, and the salt marshes tend to be the natural resources-type places where sea birds and water fowl like to be protected. Increased flushing might be beneficial, it might be detrimental. A good understanding of these ecosystems in necessary before we can really predict what could happen there.

I have mentioned storm surges already. The problem with flooding isn't usually just a storm surge or isn't usually just a tide. The problem is when the higher high water of a tide meets a large storm surge, if these 6 inches were to change the return period of a flood, it is a joint probability of these two, if it changes a 40-year return period to a 3912-year return period, I don't think anyone woud bat an eye. If it changes it from a 40-year return period to a 20 year, then we have to worry. This sort of 6-inch difference could make a flooding situation out of a nonflooding situation or it could make a flooding situation much worse than it would otherwise be if the flood, if it happen to hit at a high water time. And, almost by definition, your flooding would take place at a high water time.

Another area that you would worry about are areas built very close to high water. There is at least one restaurant built out on a dock that probably points to the fact that the highest tide of the year, its floor is about 6 inches above the water level. That seems a little improbable, and I don't understand why anybody would build there, but that type of thing seems to occur. I think maybe I'll stop there and let you ask questions instead of going into things that might not be so interesting. Senator MITCHELL. First, let me ask you, Dr. Greenberg, to briefly identify the Bedford Institute of Oceanography and your position there.

Dr. GREENBERG. I am a research scientist at the Bedford Institute of Oceanography. It is a Government institute, part of the Department of Fisheries and Oceans. It is part of the Government department.