An age-old problem13 April 1999
Observers of the US hydro industry will be familiar with some of the issues it has been confronted with — a restructuring power industry, relicensing problems and the threat of dam removal are just the tip of the iceberg. But, as Suzanne Moxon discovers, the US is now faced with the problem of maintaining its ageing dams
If asked to pinpoint on a world map where most of the hydro industry’s refurbishment work is being carried out today, many people will hover over Europe — particularly the eastern part. Gradually however, a focus on uprating and refurbishment is making its way across the Atlantic Ocean to the United States, where ageing dams are a growing cause for concern.
As the Association of State Dam Safety Officials (ASDSO) acknowledges, many different types of people and organisations own and operate dams in the US, and this is part of the problem. Fifty-eight per cent of the country’s 75,000 dams are privately owned and many owners lack sufficient funds to maintain their ageing dams adequately.
‘I would like to believe that all dam owners are well intentioned,’ says Brad Iarossi, president of ASDSO, ‘but it does take a significant amount of money to repair dams. Estimates range from thousands to millions of dollars and many dams do not generate revenue in the same way as hydro power and water supply dams. These are seen as a resource and the owners invest their profits back into the dam through repairs and maintenance. They protect their investments.
‘Dams which are used for recreation, or which are owned by smaller companies, just do not make revenue in the same way,’ Iarossi explained. ‘These dam owners simply cannot afford to take large repair bills off their profit margins as a utility does.’
So why has such a lack of resources become a major problem now? ‘Ageing dams are a growing trend in the US,’ ASDSO’S president says, ‘and in the future we will see it becoming a bigger and bigger problem. We are identifying more dams which are unsafe and a major obstacle is that we do not have the funds to repair them. The list of unsafe dams is growing and will just get bigger until we have a major disaster on our hands.’
The problem with ageing dams is that, inevitably, significant components will deteriorate. Concrete structures and water release gates get to the point where they need repairs to maintain their safety and integrity. But there are also other problems.
‘Quite honestly,’ Iarossi says, ‘the major repairs which are needed on dams are on those built over 50 years ago. This was before we knew how dams fail or before we had so much data about rainfall and run-off — most refurbishment work is to increase spillway capacity. Design and civil engineers know so much more now than they did then and can plan for circumstances, such as earthquakes or extreme storm events. Improved knowledge leads to higher standards and these dams must now be upgraded to reflect the new hazard classification.’
Another problem is the increasing pace of property development downstream from dams. ‘A dam which was built about 50 years ago would have been in the country,’ Iarossi said. ‘But in many cases there is now an out of town development below the dam. As these properties were not there when the dam was built it was designed to different specifications. Consequently, many downstream developments could be engulfed in the floodwave if the dam was to break.’
The above factors have contributed to the significant rise in the number of unsafe and high hazard potential dams across the US (see panel). ASDSO states that over 1800 dams are reported to be unsafe and, bearing in mind the increasing age of many US dams, predicts that unless action is taken this number will increase.
The useful or design life of a dam has typically been estimated at 50 years. This takes into account deterioration, improvements in technical standards and the changes to downstream risk. By 2000, 30% of the country’s dams will be 50 years old, and this will increase to 80% by 2020. The bottom line, ASDSO points out, is that while more and more dams age and deteriorate, more and more are at the same time being classified as unsafe and high hazard. And this is where Iarossi sees ASDSO paying a role.
‘We, the Association and dam owners, have an enormous obligation to ensure that dam failures do not happen. The consequences are just so extreme and totally unacceptable to society,’ he says. ‘ASDSO must highlight this problem. We have an enormous list of unsafe dams and we are getting fearful.’
Ageing dams are just part of the problem which the industry faces. Iarossi compares the whole situation to an iceberg. The tip is the actual refurbishment work and the big chunk beneath this is the funding required to carry repairs out.
‘Part of the problem is that dams are a critical component of the country’s ageing infrastructure, which includes roads, bridges, mass transportation, schools, as well as water and waste water facilities,’ Iarossi believes. Federal funds are provided to fund repairs for drinking water or waste water treatment plants but there is not a similar programme for dam owners — they are responsible for the expense themselves. ASDSO says there is a serious need to pump additional resources into state funds for dam safety and repairs, and is taking on the challenge to help struggling dam owners.
At the present time the Association is drafting legislation for a potential bill which will introduce a dam safety repair fund. It will be structured like similar programmes where federal government has recognised a need and provides funding. Commenting on the request for government money, Iarossi says that ASDSO believes the federal and state governments have a responsibility to maintain the public benefits of dams, as well as ensuring the public’s safety.
The mechanics behind the fund is that the government gives money to the state, which then puts it into a ‘revolving’ loan. The government ‘seed’ money will enable dam owners to take out low interest loans to carry out repairs. As loans are paid back this money is put back into the fund to allow more repairs to be carried out, and so on.
The fund is seen as being critical to fulfiling an urgent need in the dam industry and will be available for those who need it and where the public benefit will be the greatest. ‘Private dam owners certainly may have the greatest need,’ Iarossi says, ‘but the fund is not intended to just target them. It will be a fund for worthy projects that seek to protect public safety.’
In order to prioritise the candidate repair projects, the following criteria have been selected:
•Improving public safety and removing downstream properties from risk of flooding.
•Age of dams.
•Amount of money needed for repairs.
•Risk of failure.
•Condition of dam.
•Number of downstream lives or properties at risk.
•Ability to repay the loan. (Iarossi did stress that although this will be considered it will be one of the least important factors if urgent repairs are required.)
A competitive environment will embrace the dam safety repair fund. Iarossi acknowledges that dam owners will have to compete against one another to gain funding, while at the same time ASDSO will have to compete to get government funding for the scheme. ‘There is fierce competition in Washington, DC for funding,’ he explained. ‘It is extreme.’
Although ASDSO has not yet calculated the amount of money it needs for the fund, it is known to be ‘substantial’. Estimates suggest that US$1B is needed to repair the US’ current unsafe dams.
Envisaged as being a long term programme, a bill will have to re-authorise the fund every five to ten years. ‘When we have a better handle on the number of unsafe dams we can reduce the amount of money we need,’ Iarossi said. He also stressed the important role ASDSO will play in ensuring that dam owners guarantee that they will maintain their dams and won’t just come back in the future asking for more funding.
At the present time Congress is not unfamiliar with the hydro industry’s attempts to introduce legislation. The US government is looking at proposed legislation for the relicensing of hydro facilities. As this puts hydro under the spotlight will it ease the passage through the legal process for this funding bill? Iarossi is concerned.
‘Hydro power plant owners are the exception to the rule,’ he explains. ‘They are able to generate sufficient income to invest in maintenance and repairs. I’m afraid that Congress may portray hydro power dams as a general rule and we need to make it clear that this is not so.
‘FERC, which regulates many of the hydro dams, has more resources than the states who regulate most of the privately owned dams. Our job is to show the legis-lators that there really is a genuine need.’
So is Iarossi confident that the bill will become law and that a dam repair fund will materialise? ‘I am in no doubt whatsoever that the fund is needed. I am confident that we can accomplish it and get it passed but we do know that it will be hard work and very time-consuming to convince those on Capitol Hill. We fear that it may take a dam failure to make it happen.’ ASDSO will also be enlisting the help of Senator Christopher Bond from Missouri to sponsor the bill. He is described as ‘a wonderful champion for dam safety’ and was a key player behind the National Dam Safety Programme Act which was passed in 1996.
Currently a schedule for the bill’s pro-gress is very sketchy but Iarossi looks ahead to the future. If sufficient funding is secured he is certain that the uprating and refurbishment market in the US will take off. ‘There is a tremendous interest in it,’ he says. ‘Once unsafe dams have been identified there will be a great oppor-tunity for more work. Indeed there are probably more unsafe dams than the estimated figures suggest,’ he adds. ‘Many dam safety officials cannot get to see all of their facilities and so the current numbers may not represent a true figure.’
‘The Association’s goal,’ Iarossi says, ‘is to create a situation where there are no more unsafe dams. Our business at ASDSO is to help states achieve this and to make sure there are no more dam failures in the US.’ He went on to explain how states have very little financial resources for dam repairs as they have a ‘tremendous menu’ of other things to spend their money on.
‘To be honest,’ Iarossi added, ‘dam safety is probably way down on their list in comparison to crime prevention etc. But we urgently need to fund repairs so that dam owners have access to money, and we have to make state legislators and governors understand how important dam safety is. Over the next five years ASDSO will be very aggressive in its approach.’
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