California Colloquium on Water: Cassidy

give it some started so that we can a notorious for being part of this particular archives and it is organized in such a way that we try to broad spectrum of power obviously did not succeed the are organized consisting of campus actively trying to identify interesting speakers and who so the committee consists of Professor Joseph sacks present man ameriplan Musa apologies Michael famine in agriculture research it’s an act of civil engineering I have enjoyment we had he was this perspective with his bullet point life of all the existing and clearly believe so that please this but the last few years come some of the beings and cousin campus because engineering natural resources both vascular love letters and science and in metropolitan water with the this financial support is precious the one part of the fact that is all this time for so water unites all parcels games and when we started this hello peeps it is two years ago we just wanted to give it a go to fish not question fortunately for us decision speakers excellent so we decided to continue and all these things have a big the future in addition we have two core supporters one is it easily landscape architecture school and in other ways other co-host and and questions per day this next year we are defined with several speakers and one little value like this that a lot of little things to be dating era what is the best we have requested became this place but then I watched you watch one hand again but the absence so it looks like we have to check yes it’s like top and base macho incentives approximately advise anyone asking before introduce the speaker here is a sign of she makes all of you signed two names this and that last part this is optional we won the information right that’s how they come to introducing

other state today really you know that we hey stop this is an area to do it sir and in relation to water what more is more today than that fans have other remarkably fascinating but skin that awesome they summarize most creative engineering a lot of times they also have other consequences and today to speak about dams and water resources we have a very distinguished and of those 50 this is educating dr. John Cassidy has had a very iconic especially involved after that date a goddess soon lyrics initially in verse University of Iowa where he studied then sometimes this part but up here that adjoin better chief hydraulic you back his low experience has is wrong divination private practice nucleus and many other projects fish water balance and they here it is going to some english language this x how the major not in the mood I think it Thank You professor narsimha he dwelt on a number of things I’ve done and that reminded me but I changed jobs quite often my mother always wondered why can’t you hold a job but I have truly enjoyed working in water resources and I had the opportunity to be working with dams a lot of the time not as a damn designer but more as a hydrologic engineer determining what the output of dams would be and as a hydraulic engineer designing those aspects of the dams it’s been a long road and one that I’ve enjoyed greatly how do I get this thing to go back right here we are since there it’s a real privilege for me to be here and a little bit frightening for me too because I don’t know who’s sitting out in a audience there and I’m sure you can find plenty of questions to ask that I can’t answer but I thought I’d go back just a little bit and talked about first of all about history very briefly the first dams were constructed about 8,000 years ago in Mesopotamia as far as what history we have indicates and certainly they were irrigation dams at the time dams were also built for irrigation in Jordan and in Egypt in about 1100 BC and there is a project in China the dues young irrigation project which actually still exists and started in 300 BC and at that time have

irrigated about eight thousand eight hundred thousand hectares in large dams and according to the international commission of large dams criteria a large dam would be defined as one that is more than 15 metres high in 1949 only about 5,000 existed had been constructed at that time by 2000 there were forty-five thousand dams in the in on earth so about 40,000 were constructed in that interim period about 51 years so they were going very rapidly one a day or more than that in general the benefits that dams have achieved or are manifold and in general those of us who worked in that area like to believe that the benefits were easily recognized and we’re certainly well worth the effort that’s spent we’ll talk about that just a little bit later more in more detail but benefits have been in for the very large part irrigation projects all over the world some of the largest of all in India and Pakistan and in the United States as well the electrical energy is certainly the one of the major benefits particularly in developing countries where energy is so in such critical need and just not available in u.s. hydroelectric power along about the end of the 40s and beginning of the 50s began to be in somewhat in disfavor because it was looked on as as peaking power and peaking power wasn’t considered to be very valuable at that time the situation just changed now we have large base load power with nuclear plants and other thermal plants and peaking powers become the most valuable resource and as such then hydroelectric plants have in themselves become real cash cows when they’re operated correctly municipal water supply and obvious thing for most dams and supplemental navigation downstream the dams on the Missouri River or certainly classic examples of where a major benefit has been to supplement AG and navigation on the Lower Mississippi and over Missouri rivers flood control probably was the second most important aspect of the design and construction of dams and particularly here in the United States a great many have been built with the major element those flood control now for a long time recreation was not considered an economic benefit and was back in the fifties when the argument began to rage that you could justify building a dam and include recreation benefits and the federal government finally was able to achieve that through Congress back in the 50s so the multipurpose dam could be justified on the basis of economics considering power generation navigation irrigation and recreation as well now there are many different types of dams and somewhat i’m going to show you here sure ones that you’ve never seen a pretty deliberately picked dams that wouldn’t be familiar to everyone as traveling in peru a long time ago and this is a tailings dam tailings dams are probably as common as anything else throughout the world and they’re also the ones that tend to be the most hazardous because they usually contain a lot of heavy metals behind them and often often chemicals that when released or harmful this i thought was a very interesting one it’s just about 800 feet tall 250 meters or so and you can see it’s been stepped up from the downstream side it’s manufactured totally with tailings and you’ll also note that there’s no spillway on it but these these are not uncommon in south america this is a strictly of power damn bechdel design and built this some years ago on a kaulitz river in southwestern Washington it’s a unique design and that you you don’t see the powerhouse the generators and turbines are contained within the dam there are hatches in the spillway surfaces that allow you to remove and place turbines and generators

through them but except for the switchyard it doesn’t look like a power dam at all yet it’s a has been at this point very successful and economically strong generator this in general purpose dams this is one that has a great deal of purpose this is Kariba Dam in Zimbabwe had a lot of technical difficulties with this for a long time because of erosion in the pool downstream from the spillway and you may have seen a lot of classical papers related to this it has a huge reservoir behind it generates a lot of energy in a country were aware there is very little energy to be had sinned Zimbabwe and Zimbabwe has all kinds of strife going right now and I’m not sure it is what’s happening with with Kariba Dam they’ve also had a tremendous change here environmentally because the reservoir itself when it’s filled the the fish population and the reservoir totally changed from what they had previously and somebody planted sardines in it and now it in part they harvest sardines in great quantities out of Kariba Dam in freshwater I’m not sure any of you but I even realize that they would flourish in that but they do utter type of damn strictly flood control this is the one that crosses the waterway and in Holland and prevents storm surges and water from flooding the the fields of Holland and that is strictly flood control and ever since but here’s a case where environment was drastically changed as a result of this damn from a sea shore environment to an agriculture one of significant beauty but has never been considered to be negative it’s always been positive and ever since this is three gorges dam it was it’s so big this is the best picture I could put together of it it’s in an artist’s rendition been over there a couple of times a tremendous amount of disagreement as to whether this damn should have ever been built it will displace about over a million people perhaps as a result of all of the demonstrations and agitation the Chinese have been working very very hard to take care of the people that are being displaced they are building a new housing upstream rapidly much better housing than the people have lived in before and they also have significant training programs going hoping that they can attract somewhere in a neighborhood of a hundred to two hundred thousand of these people to leave in agrarian lifestyle and move to Shanghai and work in their technical industries where they need people they have more people here than they will need once the the dam is completed but in Shanghai they have very big needs of technical people the damn right now is I would say about a half complete or so they have diverted and the left side of the dam is the concrete portion of it is nearly finished the lock structures there are two lock systems five lakhs in each of these systems to lock major vessels upstream and downstream and there’s also a ship lift or a ship elevator that handles smaller ships their chief reason for building this is flood control on the lower Yangtze and to provide enhanced navigation to Chungking upstream yet currently the water gets low enough during a summer that only very small boats can make it all the way to Chongqing and so they which is the heart of another industrial part of their country this is Folsom dam you may recognize this that was two pieces there back in July 1995 the major one of the gate number three lar very large Tanner gate failed on this when they were starting to open it and it created quite a concern about dam safety within California dam safety had been a major issue in California anyway but this began to make p age enci particularly Department of Water Resources dam safety people concerned about whether gates in all of the other dams that had this type

of gates might be a problem Folsom has another unique problem in that it it really can only pass about a 500 year flood without being over top which is a very small flood for a major damn like Folsom with several million people living in in a flood plain downstream and they are currently the Corps of Engineers is currently trying to come up with schemes to increase the capacity flood handling capacity of this damn one of them you’re familiar with I’m sure is building Auburn dam upstream which was killed many years ago a beer reclamation attention whether Auburn will ever be built or not I’m not sure it’s been being studied and every year it comes up but currently the core is looking at all the upstream dams that exist and trying to talk damn owners into allowing them to fund a increase in storage capacity for flood control if they can get all of the owners to do that they can actually increase the capacity of Folsom they believe to where it would pass the problem axonal flood without serious danger negative impacts of dams have been very much in the forefront for the last ten years particularly but even before that 15 years the prom major problem being that lands are inundated every time you build a dam and flood the reservoir you displace people and as I mentioned in Three Gorges they’re going to displace about a million it changes the river regime entirely a downstream conditions are altered settlement is not passed downstream in the same way it was previously and the peak flows are not the same so lots of arguments now that perhaps environmentally the river regime want to be retained to the degree that you possibly can that’s been a big issue on the Columbia River for for some time now it changes the habitat and the reservoir drastically i mentioned in kuriboh were totally different fish population also changes a fish habitat downstream for example in the Midwest dams constructed there who are usually on waters that were warm and heavy bass populations at them with the high dams now such as Table Rock in the southwest Missouri a very cold water coming out of the dam and so the fish population is switched from bass to trout all the trout fishermen think that’s a very good deal the bass fishermen are not so sure the biggest concern seems to be that in many cases the predicted benefits did not were not realized and for particularly a lot of dams in foreign countries this the owners and the developers and engineers have been accused of never of the dam never meeting what it was achieved the as a result of all of these negative concerns the world Commission on dams was convened back in 1998 we had I was quite active in the international commission on large dams for many years and for about five or six years running we would have active demonstrations at every one of our meetings by anti dams people American the Friends of the rivers American Friends of the rivers and various other international organizations the criticism was not not directed only at dam so we felt it very much there but criticism is leveled at a lot of other things and a touch on that briefly just a little bit later but this world Commission on dams is an international commission it was funded by some 53 corporations and agencies the and and foreign governments as well put some money into this they were charged to make a rigorous independent global review of dams and what had actually happened two dams that had been constructed and what were the actual impacts and how important were they they the opposition to dam building has points up here as old there are records in medieval England where boat owners objected violently to people who built mills and and put diversion dams across

the river to divert water to power their meals 17th century Scotland’s and fishermen destroyed a milliner’s damn because it cut off the path for the salmon to get upstream in 1900 in California many of you may remember John her have read about that John Muir bitterly opposed the construction of het Hetchy damn because it flooded a very beautiful Canyon with in yosemite national park that was bitterly fought and the federal government finally went against John Muir and allowed the city of San Francisco to build it the city of San Francisco felt that they really had no choice they needed a firm supply of high-quality water and that was one place where they could get it now the modern opposition to dams is based on primarily on social and environmental concerns what happened to the people were displaced by the dam did they receive any benefit as a result of that damn being constructed and what was their life like after the dam was constructed as well as environmental concerns we’ve mentioned that that downstream river regime changes in a habitat within a reservoir changes drastically as well worldwide demonstrations have occurred then big demonstrations on the Narmada River against the high dam norma da dam demonstrations on the narmada river against another damn further upstream his name escapes me right now and as a result of all of these the World Bank began to change its policies and procedures the World Bank has a long time been the primary funder of water resource projects around the world International Monetary Fund and the World Bank also fund other things they fund the natural resource projects including mines they fund infrastructure projects including urban types of things and there have been objections to some of those things not just dams recent opposition to World Bank projects that were proposed there were only there were 12 dams that were singled out as being opposed three gorges as one of those are a couple of in in indonesia the norma da dam in india there were 14 forests and natural resource projects were they were going to reforest large areas and harvest Natural Resource resources there were five minds and industrial projects that the opposition felt were not being evaluated correctly and if evaluated correctly should not be funded and there were two urban infrastructure projects one of these was in Indonesia i’m not sure where the other one was the central issues that the world commission on dam is found in their studies were costs and benefits dams simply had not produced the benefits that they thought they were going to produce or were projected to produce and there were serious cost overruns many cases that cost overruns were fifty to a hundred percent and in one case even one hundred and eighty-nine percent of the original cost and I’m sorry I’m you the environmental impacts have always been a major issue social social impacts and equity who shared in the benefits of what was going on and what were the economics actually achieve did the project pay for itself in the end and finally governance and participation who governed the project who had voices in what was being done and how it was operated and finally the opposition maintained that in many many cases alternatives were not studied for example if a dam was being built for hydropower primarily why didn’t they study wind turbines other other situations other things like that if it was irrigation what they could have looked at some other means of as well the world Commission on dams decided to

make seven detailed studies of large existing projects in the world first one is Grand Coulee in the US then to Correa in Brazil which is in the northern part of Brazil aztlán toes in Turkey a large irrigation development on the longer you Freydis River glowa and Laden basin in Norway big hydro development scheme tarbela in Pakistan pokémon and Thailand kariba in Zimbabwe we talked a little bit about kariba Grand Coulee was built back in the early 30s and one of the things that was brought out there is that the Yakima Indian nation was displaced but was never consulted at all as to whether they felt this project was necessary or desirable and certainly never shared in any of the benefits Grand Coulee is one that has paid out a long time ago it generates enormous and of electricity we benefit from it down here in Grand in california since we have an inner tie to the northwest and our utility companies here purchase a great deal of energy from the northwest as a result of that tarbela has major problems some of you may realize that major problems are that sediment is rapidly filling that reservoir in a major wedge the sediment is moving downstream at the rate of several kilometers a year and there appears to be no way that this can be stopped or mitigated it’s it’s very serious problem tarbela was one that over an estimated cost by a good deal more than a hundred percent now the conclusions the world Commission on dams made I’ll just read these and afterwards they’ll give you a few of my own personal opinions the first conclusion was that in too many cases an unacceptable and often unnecessary price has been paid to secure those benefits especially in social and environmental terms by people displaced by communities downstream by taxpayers and by the natural environment somehow I think I skipped a slide here now here’s this is the first conclusion first conclusion and they put this right up front this was number one it says dams have made an important and significant contribution to human development and a benefits derived from them have been considerable there’s been a lack of equity in the distribution of benefits this is called into question the value of many dams in meeting water and energy development needs when compared with alternatives you by bringing to the table these were really suggestions now but they were conclusions but by bringing to the table all those whose rights are involved and who bear the risks associated with different options for water and energy resources development the conditions for a positive resolution of competing interest and conflicts are created that sounds very easy in practice I’m afraid it’s far from easy and negotiating outcomes will greatly improve the development effectiveness of water and energy projects by eliminating unfavorable projects at an early stage and by offering as a choice only those options that key stakeholders agree represent the best ones to meet the needs in question agana a very honorable intentions certainly the world Commission on dams report final report I have a copy here I can’t loan it to you because it doesn’t belong to me but it it’s very interesting if the library doesn’t have one the library ought to get one I think okay it’s worth looking at in my estimation the report is is quite biased it was intended not to be biased in any way their full intention to try to devote to appoint commissioners with the range of interests but it’s clear that they

didn’t escape a bias against dams they’re in many cases will discuss the benefits of a damn for example Grand Coulee with enormous financial and economic benefits to the northwest had been been enormously important in developing key industries of aluminium thing just about just a few sentences about that but in several paragraphs about the negative effects of Grand Coulee Dam Grand Coulee Dam was the first one built on the Columbia River and so it cut off the salmon which used to spawn almost a thousand miles further upstream interestingly enough you go back and look at that you find that they had fish biologists look at this study look at the dam side and decide what to do and they recommended not trying to build fish ladders and that now today I doubt that you could find any honest fish biologists who would come to that same conclusion but the thought was that that was not an important issue that generating electricity in providing water for irrigation was far more important and that any loss of salmon as a result of that could be made up by building fish hatcheries and everybody would be deliriously happy after there are many cases many items along through this report where that same sort of bias seems to be there is always a little bit of the negative dig there however i think the suggestions that as too far as planning and organizing people to review these projects who actually represent the stakeholders is vital and that oh i was very interested in that because i really didn’t know how much of that had been done i’d never worked on a government project i know a couple of years ago my wife and i were up in a weary northwest corner of Montana on the on the Kootenai River where Libby dam is built Libby dam is a high concrete gravity dam built primarily for power but also a flood control and and conservation storage and while we were there just happened to meet a bunch of people who had formed an organization of former owners of land that had now been displaced by the reservoir and it was interesting to talk to these people because when the project had to go ahead and had fun him to go ahead the people who owned land within the reservoir had no say in this at all one day some guy would knock on that door the ranch house and and tell you that I’ve got a check here for your land you’ve got until a year after next some time to move out and there was no negotiation here that was it you bought it the land was condemned this is a public project of public entity doing it and under the law they could do then it took quite a while that Dan was finished in 1968 but four years ago this organization began to fight it and as a result they finally got the Corps of Engineers in bonneville power to agree that everybody or family members of the people who did on land in the reservoir the time the vent dam was built should share in the benefits of that reservoir directly and that’s energy and so now they get a annual payment from electricity revenues Matt damn and they don’t go blow it on cars and parties they have actually bought a couple of hydro projects up in Canada and created a foundation and the foundation is providing scholarships for for youth and other people who want to go to school and study so they’re they’re looking at handling this in a wise way and using that resource in a way that would benefit everybody yeah who was affected well I think that’s the worst problem that has occurred particularly in foreign countries if you look at the projects in Africa rarely did the people who were displaced ever receive any benefit whatsoever from the project the

Aswan Dam hi aswan dam is a fairly classic example there were a very large number of namibians I don’t remember several thousands living in the upper areas of that reservoir who were displaced and moved back into sedan and received absolutely no benefits whatsoever from from the project so I think this has been the biggest source of friction through it whether the world Commission on dams we work can provide a way to mitigate some of those problems whether it can change the way in which projects are planned and constructed still remains to be seen in the United States things have turned pretty strongly we have in the United States about I think 13,000 dams in the state of California we have 13 hundred and fifteen I believe or 16 depending on how you count them vary the pace of damn building since about nineteen eighty has been very very slow but nevertheless in the United States last year there was still some thirty six dams under construction here in California within the past two three or four years that several major dams completed los Vaqueros out here that augments the water supply for contra costa county a very strongly needed facility because in drought years those of you if any of you live out there know the water got pretty salty then contra costa water district so now with los Vaqueros it’s an off channel reservoir they pumped directly from the river in times when a great deal of fresh water is available i fill the reservoir and then when they’re what when the flowing river is low and assault wedge gets far up then they can supplement the water with releases of koala high quality water from los Vaqueros to other off stream reservoirs have been built or one is being built the other one is finished in southern california eastside reservoir built by Metropolitan Water District a very large off stream reservoir it will be filled with state water project water and water from the Colorado River when that’s available 11 hime reservoir is under construction now for the city of San Diego San Diego County Water Authority same function again it’s off channel it’ll be filled by pumping state water project water into it in times of surplus and then using it in times of emergency very very expensive if you consider how much the water actually costs that comes out of that they they don’t give you those numbers kind of hard to do because of the way those projects are operated it’s hard to decide what real yield of them will be it there aren’t very many dams if any they’re being constructed on main stream channels currently most of the cases are new dams that are replacing old dams that have been in trouble several back in Pennsylvania built in recent years that way that have replaced ol dams we don’t have many sites left in this country for four major storage projects on main streams so that probably will not ever become a very big effort in the near future I and somewhat biased I know in in my opinion of the importance of dams and benefits that they provide I’ve had a career that I’ve enjoyed a great deal and what is it done it’s given me a lot of first-class travel opportunities and this is one that had them though thank you very much with that all they’ll just quit here and if you have questions I’ll try to answer them what’s the technology of sediment control once used in the three four three gorges is strictly a sluicing process they they have 26 large low-level outlets that are open during

flood season when heavy sediment loads are coming down and they pass that through the reservoir will actually be pulled down something like 20 or 30 meters more an ass but about 50 meters be pull down about 50 meters during flood season and those low-level outlets will be opened as many of them as necessary to to keep the reservoir stable at that level and that passes a heavy sediment load downstream now they have another another dam downstream Days of Awe which has been there since about nineteen eighty-four it has not had sediment problems they have the same design at gaze of all the Barrett with the large I think it’s 28 low level large low level outlets there that operated the same way there are sediment deposits in the reservoir above Gaza bomb but they’re they’re not drastic they don’t create a navigation problems they haven’t seriously curtail seriously reduce the storage and as a result of operating that damned since about nineteen eighty-five they feel that they know how to handle how to operate three gorges dam as well and they don’t feel that they will have an accretion of sediment that this is a serious concern they’ll have some it’ll no question about that they have studied that thing in a number of different ways they’ve modeled it analytically they modeled it with a half a dozen different hydraulic models using coal dust and some and sawdust and others and plastic beads in a third one they’ve done a great deal of study on how to handle the sediment because that is certainly a major issue yes give it a damn you have life span what do you anticipate as the problems that you generate sediment is certainly uh oh i’m sorry what question was what do i think the problems are going to be that future generations have to handle in the life spans of dams one of the major problem is going to be sediment and off a lot of dams that were figured to fill up in about a hundred years with sediment at the time those predictions were made probably weren’t very good but nevertheless they’re real and the sediment is going to be a significant problem it’s a very difficult problem to handle once it’s in the reservoir d the loss of Riverside County Flood Control District has three dams on San Gabriel River in n down in a Los Angeles area Morris Dance and Gabriel dam and the third one whose name escapes me they are the only organization I know of in the world that has actually cleaned the reservoir out those are flood control dams and because of the tremendous value of downstream property they can actually justify going in and cleaning them out and they clean them out by just dropping the reservoir drop draining the reservoir then going in with earth moving equipment and moving it out but they’re in serious trouble because they can’t get land from the forest service anymore to put the sediment in and that those dams really don’t have any serious environmental problems with a sediment in a lot of places you have heavy metals and PCBs and other things to worry about so there is a big issue as to how to handle that the maintenance issues as far as the structures and cells go are probably not a problem in many cases dams are going to have to be rebuilt concrete dams built back in the 30s and early 40s often had problems of alkali reaction and the dams have cracked and and are becoming a maintenance concern they will probably have to be rebuilt in most cases it probably will build a new dam downstream and tear down what they need the design will have to agree with whatever the situation has there anything else yes barbecue with the sentiment what what did they what did Riverside County do with the sediment they took out of these dams they took it out with earth moving equipment and they were able to get land from the Forest Service to actually stock pilot they filled up a

couple of large ravines with it they looked at a possibility of mining it commercially that hoped that maybe that would be valuable enough that they could take it down stream in a couple of the old gravel pits down there and dump it in and sell it to concrete manufacturing plants nobody really wanted to do that it would have cost more than they could get their gravel for as it was so they’re just filling up a couple of ravines along the river yes figured am could your repeater I’m sorry yes yes it’s a terrible problem the foundation for the dam is not good it’s a very deep alluvium and in order to build a dam there they built a very long apron upstream and had to make a long percolation pass so that they wouldn’t get piping through there but it’s a very difficult situation at this point nobody has come up with a decent answer as to what they could do raising the dam is is very difficult maybe maybe impossible but certainly very difficult i’m sorry i didn’t i didn’t repeat the question what what can they do to tarbela damn because of this serious sediment problem the reservoir is filling up rapidly say that the jury is still out on that yes exactly in hydroelectric generation of methyl mercury that is exposed to when you operate the reservoir get methyl mercury am like for example from the deal structure public utilities like BGE involve public they sale the public and repeat purchase which leaves environmental liability the public and the benefits with private damn operator and I was just wondering what the credibility is for that night Thomas office in the United States I’m sorry I then follow your first part of your course methyl mercury and hydroelectric dams current of pge record buying and then selling and then by that okay so that the environmental liability stays with the public and the benefits go to the private and I just wondering how physical solutions to some of these problems can have any credibility at all when that kind of transaction is done question was when you when you’ve got a utility company that is selling their property and then buying it back or selling it again and the ownership begins to get confused there as to who is responsible for cleanup if you’ve got the serious pollution problem it looks great yeah fanta I think probably the courts will ultimately come to grips with that I don’t think anybody else will but it’s going to the person who caused the pollution is probably going to have to clean it up but it’s it’s not clear how that’s going to be done yet I wish I could tell you but I really don’t know yes what what what future damn design might look like particularly related to sediment problems and other things up Wow the status of damn design in terms of just a basic damn hasn’t really changed a whole lot in in probably at least 50 years we do a lot better job of it now because we can analyze things a lot better with finite element methods and other things so we more confident however the standards are much higher now I think as far as sediment problems go the the only real solution to being able to extend the life of a reservoir subject to large sediment inflows is to build in sluicing capability the damn that I showed you college falls down the hydro dam where you couldn’t see the power plant is that

way on the right hand side of that reservoir of that dam there there are two fairly large outlet tunnels that lay right in the bottom of the river it’s gravel bed river during flood season it brings a lot of small gravel down the river when we build it we built a coffer dam upstream coffer dam in order to do the construction we left that copper dam in place it angles across the river and then the to low-level outlet works come directly under the damn from the end of that coffer dam so that when the flood season occurs the reservoir can be pulled down you increase the velocities to the reservoir and then at the dam that copper damn tends to deflect the gravel into those low-level outlets and flush it past I think that sort of design is probably what is going to to be required and in many more cases now and this sort of operation will be f will need to be studied in much more detail and it has in the past well they’re doing it in three gorges they’ve got it on case of all both of those are large dams are more than 300 feet high and large reservoirs and has worked successfully on three gorges down on Days of Awe at this point I think of its handle right the question is I’m sorry I didn’t repeat the question again she asked that the sluicing operation i described for Calais Falls is okay for small dams what do you do for large dams and the question on large dam is how much the drawdown do you need in order to get sufficient velocity through the reservoir to to carry enough sediment out to make a difference what it probably will mean is that operation needs to be done much more carefully and you need much more data to do it and a major damn like that should never be built again without very good upstream data on rainfall and and stream flow and to provide for real-time operation in order that you can finally close the gates and capture enough run off to make the project meet its beneficial predictions as well yes do you see a locally or something as I heard a question said you asked about dam removal and did you say I’m sure you’ve all heard about the the argument that the three of the dams on the lower snake river ought to be torn out there is Lord granite upper monumental and ice harbor their big concrete and earth fill dams to date no major dams have been have been torn down there have been some several small dams that have been pulled out there’s one up and a couple up near chico and butte creek that we’re torn down a year or so ago would have been several back in the east coast in massachusetts in order they were torn down in order to allow an adder miss fish to move upstream the scenario as far as tearing down the dams and the Snake River is far from clear at this point tremendous benefits accrue as a result of electrical energy and flood control for those three dams I personally don’t think the fisheries people really know what will happen if they tear those dams out you still have all the dams on the Columbia River for the fish to get through back in about nineteen eighty-one the US Fish and Wildlife Service in the end the National Marine Fisheries Service were convinced that the most serious element in mortality to the Sam migrating salmon was the length of time it takes them to get through the dams and down to the ocean for quite a number of years they tried to trap fingerlings coming downstream at lower granite put them in barges and take them downstream and put them back in the river below Bonneville

Dam the last dam on on the Columbia in spite of that runs going back up the Snake River been getting smaller and smaller to the point i think five years ago i think there were only 20 sockeye salmon and went upstream past lord granite however at the same time the the steelhead trout were flourishing they’d get better run the steelhead trout on them on the Salmon River now than they had in history and it can’t explain in a wide of the steelhead and runs thrive there and the salmon runs don’t and they’re handled the same way you can’t distinguish between them in the fingerling stage I really don’t think anybody can safely predict whether taking those dams out would make a significant difference in the salmon runs or not there are people on both sides of that fence and I certainly don’t know enough to pick a aside to be on it’s a tremendously expensive thing to do to tear those dams down and there would be large amounts of sediment go downstream what the environmental effects of that would be I don’t know yes feasibility of what again retrofitting you know you do anything with money if if you can do that I was over in Sudan last year on a dam on the Blue Nile Rosie Ruiz damn very very important damn to the Sudanese it provides irrigation water for a lot of acres there and people are starving over there they don’t have enough water the dam is silting up good deal faster than that anticipated it’s causing physical problems and the outlet works erosion we’re looking at that to see whether there was a way to improve it it’s got to for a low-level outlet works and they’re pretty big whether something else can be done to improve that or not I’m not sure they’re there are certainly if you’ve got the money you can do that and if you can demonstrate that it’s worthwhile doing I suspect it will be done particularly we’re dams where there’s obvious benefit to them benefits that would be real benefits in terms of energy production in terms of maybe it’s some downstream in-stream flow enhancement as well is there expensive to do on an existing damn concrete dam not so bad you can can drill holes through it and and probably put them in without seriously affecting the integrity of the damn earth dam Rockville damn much much more difficult situation to do you might be able to do it you know by going around through the abutments of the tunnel but that causes problems in itself it I don’t know I that’s not something I thought very much about your privacy and to help and the other thing would be what you need to reason is that so many dams haven’t realized there the question is if should you include the cost of taking a damn out when you estimate its cost in the beginning and make your predictions as to what costs and benefits are going to be and then secondly as to why haven’t dams met their predicted production benefits in the first case probably has to be done now you at least should be thinking about what that has to be done however most dams last a long long time lots of dams in united states that are 100 years old now and still functioning fine the rudders though that aren’t near that older our filling was sediment enough functioning very well it’s more a matter of careful design and careful studies ahead of time to to make a more reasonable estimate of what the lifespan

of the dam is going to be but certainly that ought to be part of the plan as to what might ultimately happen to that damn however political directions tend to be about four years in lengths and by the time a damn reaches the end of its life span they have no idea what the political element will be at that point the other part was why hemet dams met the goal I think for them for the most part the most serious ones that have failed to meet goals have been irrigation projects and this has usually been a matter of over-optimism I believe in what could have been produced in those croplands what it was going to cost to actually develop the irrigated land in many cases they never did reach their ultimate goal in terms of the number of acres that were to be developed sometimes because the land just wasn’t good enough to be developed other times because they had drainage problems that and the salt began to be a serious problem to them and they didn’t have money to build a drainage most of the time I think it’s been political difficulties in developing countries where graft has taken an awful lot of the money out of out of the benefits of the job oftentimes graft took an awful lot of money out of the front end and the project didn’t get built to the standards that it was intended to I don’t know how you correct those you just hope that these countries can get their act together and that organizations like the World Bank have better control on the money that they loan then they have had in the past about these large heads and operating still well both question was how about dams large dams and their their life span is running out what do you do at that point to rebuild them or to build a new dam is the old army response used to be it depends on the situation and the terrain a lot of dams can just be rehabilitated and made a bit stronger there’s a couple of dams in California that became worrisome because of earthquake loadings and they built roller compacted concrete berms on the downstream side too to strengthen them so there’s a lot of rehabilitation measures that you can do to to improve a damn’s condition if it gets to be too bad it has to be rebuilt and number back in the co about 1978-79 I guess American Falls Dam on the Snake River in in Idaho it was built very early back in the early 30s but by irrigation district there and actually be a reclamation design that build it for them but it had very serious Cronk read aggregate problems and dam was cracking very very badly and became very much a safety concern so a new dam new concrete dam was built downstream from the old one the old one continued to operate all the time that the new one was being built finally the old one was built and the irrigation season was over they pulled the reservoir down and blast it off as much out of the top of the old am as any to be able to get the good operation for the new damn those situate what you do is going to depend on the best and most economic way to do it say many dams in this country are approaching a hundred years of age and still operating a lot of them are over 50 years of age and and operating just fine they they take maintenance there are regulatory authorities in each state Dam Safety Commission’s that inspect dams regularly and require owners to to keep them safe the Federal Energy Regulatory Commission in Washington DC requires a full inspection of every damn that generates electricity every five years with a written report by an independent consultant and forces those companies to

spend money to upgrade the dam keep it safe if question was as terrorism concern with dams I’m sure it could be it’s not easy to knock out a damn you can can’t do it it’s been tried a lot of times a back during World War two the Allies spent a lot of time bombing dams in Germany and did to actually get one to fail finally and and cause a lot of damage downstream in Yugoslavia want to serve the sill f’d Bosnia they placed an enormous explosive charge in the bottom of a large concrete gravity dam there it caused a whole lot of damage but the damn didn’t fail in fact it does Harley leaks but it’s not easy to to do that the terrorism would take an enormous amount of explosives in most cases to do much I’m sure somebody’s looking at that but I haven’t been involved in it yeah I heard that some alternative proposals for let’s say Hetch Hetchy taking down damn and maybe building some smaller dams way or for Hoover Dam so would any have you heard about those proposals and would think about this question was have I heard of proposals were taking out Hetch Hetchy dam and and hoover dam and rebuilding with smaller dams i I’ve heard some people talk about such things but I don’t think a very serious talk it would be enormously expensive to begin with I’m sure that a lot of people would like to see how had she taken out heaven only knows what how long it would take for that Canyon to recover to a point where it was as beautiful as the asst emiti valley but maybe it’s worth doing it depends again on on what your values are hoover dam there’s there’s an awful lot of water stored behind hoover dam and flaming gorge damn on a glen canyon dam on the colorado river that water is enormous benefit to arizona on nevada and california i doubt that you would ever get to political strengths to ever take neither one of those dams out and he certainly couldn’t replace them with smaller structures it just probably just couldn’t be done the world Commission Monday on study if it had any effect of making a difference in actually question was what impact has the world Commission on damn study had as it has it had an impact in stopping dance I’m sure it’s had an impact it’s gotten a lot of attention they are in the process now establishing a group tour will be charged with going around the world and getting the information that’s in that report out to the various countries and various entities that are involved in this hopefully they won’t have a major ax to grind and going in one direction or another I hope they’re impartial that hasn’t been done yet they’re they’re starting at this point the results certainly have been disseminated widely among the damn community the people who design and build and on dams they know about this and have heard about it a great deal as far as going beyond that I’m not sure the World Bank certainly they spent a good deal of money in getting this report together I’m sure that they will use it in whatever way they can say I hope that it it doesn’t come out and be promoted as biased as as it sounds and in places I I feel like they really did not do justice to the benefits of dams certainly have been bad mistakes dams I personally feel that most of them have been a situation where political climate just didn’t allow or didn’t require proper planning and treatment of the people who were to be impacted I believe myself very strongly that people displaced should share in

the benefits should share directly in the benefits that hasn’t been the case in in a lot of cases I just wondering what role you envision the consultants plane in this we traditionally engineering firm to broaden do a job and it certainly might not be in safe at Gold’s are you our asses best interest to come in and say well did you ask the right people before we build this dam and but on the other hand consultants have a lot of power to affect their clients so I’m just curious but maybe you could just give an example what Bechtel is doing or protective Bechtel they might question is what role consultants play with this new approach to planning and design for dams the Bechtel responses get out of the business that they don’t do much engineering or construction anymore and project management almost totally my guess is that it won’t change the consultants rule very much except it’ll probably bring more people different people into it will bring planners into it earlier that will have a more of an environmental bent and more of an economic view of things and that it will improve the planning process and in the World Bank and International Monetary Fund all retires require an older building a major damn to have an independent consulting board I’m sure that the world bank will not improve an independent consulting board anymore unless it has some people on it besides geotech sand concrete and hydraulic engineers you’re going to have to have boards that span a much wider part and probably what it will mean is that there will be consulting boards separate consulting boards early in in the stages there will probably be a consulting board that is more of a planning entity that looks at all of these issues once that’s done there another board it develops conceptual designs and finally feasibility and final designs and that the final design probably won’t contain these environmental people were political people anymore they’ll be back in engineering sir hell yes possible water birds listen interesting request a question what about fish kills and water turbines a very interesting question as I mentioned earlier that back in about 1980s like that National Marine Fisheries Service and a fish and wildlife service were convinced that the length of time it took the fish to reach the ocean was the most serious cause of mortality turbines second most serious was predators seagulls and into Columbia River seagulls and fish sitting downstream from the dam picking up stunned fingerlings as they came through the turbines somewhere along the line somebody lost sight of that I think and what money that’s been spent and have been probably two or three hundred maybe four hundred million dollars spent trying to screen fingerlings out of the turbines and he always seemed to me like this is a strange way to approach this problem is to pick the least the element of least mortality to go after and try to eliminate it what they’re doing on the Columbia now is trying to screen them out of the turbines and put them right back in a river downstream now they’re trying to find places downstream that we will be somewhat predator-free but my guess is that predators probably smarter than that predators will probably go where the fish are yeah so but there is a major research project underway by Department of Energy to develop a fish friendly turban I think have been somewhere in the neighborhood of 35 million dollars devoted to that so for Alden research laboratory back in an old and holden massachusetts as one part of that where they’re developing a totally new runner the runners looks more like a corkscrew the idea being that there won’t be any where you have to have a single layer of blades on a turban you have a very drastic pressure change from one side of the blade to the other and it’s felt that this is a major source of damage to the fish Walden’s idea is that if you don’t have that if that’s distributed throughout this long court you runner that they won’t have the same mortality they’re just this year going to go into mortality tests with that using rainbow trout voice had another piece of that action their

approach was to better design the turbines that they have getting smaller clearances getting blades that are more designed in a more friendly way and I’m not sure what that is but anyway they’re trying to make their existing turbines further existing diet designs more fish friendly what will happen out of that I don’t know it’s there certainly a lot of interest in doing that as I say it seems strange to me because that’s that’s the least cause of mortality among the fish but that’s the one thing I guess that you can address you can’t change the length of time they go downstream unless you barge them not personally think that hasn’t been looked at anywhere near as seriously as has they’ve done it they tried barging them and then but the returner the fish returning are still going down but nobody knows for sure whether it’s as a result of the barging or whether it’s a result of fishing or disease or something else out in the ocean for quite a while it’s a big fight going on that the fisherman said it was a damn’s the dams are causing all the problem damn said oh no it’s not the dams it’s a dog on loggers all ass and getting the spawning bed is ruining spying bands they can’t do it logger said oh no it’s not us it’s the Indians they can fish and take all the fish they won their killing them well the Indians haven’t taken any more now than it used to take years ago their records are pretty clear but this this is where it is it goes around around in a circle nobody is really accepting the blame for it yeah time for one last question if not that you thank you thank you for a very very educational talk a good combination of engineering and human beings Thanks like you you