Making It Non-Detrimental to Society
Bert G. Shelton, Research Scientist and Professional Engineer – June 8, 2009
It is said that expanding the canal will benefit everyone. The Panama Canal’s cargo capacity is to be nearly doubled by the planned expansion, which is to add a single new lane for transiting Post-Panamax ships.
Increasing the canal’s capacity has been long desired and seen as good, so it is difficult to argue against its expansion. However, is the chosen single-lane system really the best option and in the best interest of shippers and of society, who will ultimately fund the project?
An independent review of water-saving and operational techniques has identified better lock systems that have been around for more than 100 years, as well as more recent ones that would be far more beneficial and cost-effective.
As an example, an alternative single-lane system arrangement that has locks like those currently planned – but with 4 chambers (instead of 6) and 2 tanks per chamber (instead of 3¬) – would use 45 (instead of 52) million gallons per transit. Not only would this system have fewer parts and use less water per transit, a dike over geologic faults would be unnecessary and Gatún Lake would be spared from becoming brackish.
However, with any single-lane system, an unexpected problem at any chamber can shut it down.
To avoid shutdowns, a two-lane alternative with 8 chambers – and no tanks – that also uses 45 million gallons per transit could replace the currently planned system. The Panama Canal’s Pedro-Miguel Lock unit is an example of that system’s type of locks. Water use could be further reduced to 30 million gallons per transit by using a recent improvement that adds 2 tanks to each unit of that system.
As with the single-lane alternative, both two-lane systems would avoid the problematic dike presently planned, and Gatún Lake would be protected from salt intrusion.
Either of these two-lane arrangements would make it possible to markedly increase canal cargo capacity, which means more growth in future business.
The planned single-lane lock system presents no similarly obvious advantages. It offers relatively fewer transits for the water used, despite having many more components.
Benefits from the alternatives found during the review, on the other hand, are clear.
The single-lane alternative initially studied – which could transit at least 9, possibly 10, ships a day – has 2/3rds the chambers, fewer than half the tanks, and uses 13% less water per transit than the planned system.
At first glance, the simpler single-lane locks would appear to be more cost-effective than those planned, when considering the transits obtained for the money spent on locks. However, even though more efficient, the lower total capacity of these simpler locks would likely not generate sufficient profit margin to pay for the expansion’s total investment.
Thus, in addition to targeting higher efficiency, the new locks also need to be able to handle more transits.
The two-step two-lane system noted above – which also uses about 13% less water per transit – could easily transit more than the 12 ships a day now planned. Assessment of it confirmed that it would be more cost-effective to build than the planned three-step single-lane system with 6 chamber and 18 tanks.
Because of its two lanes, its chambers can perform the dual function of transiting ships and saving water. Increasing the number of chambers from 6 to 8 implies that this lock system will cost at least 1/3rd more than the planned system. However, that implied increase in cost is significantly reduced by the elimination of 18 tanks.
Additional money is saved by not having to build a very risky dam across geologic faults, as is now required. That not only reduces the cost differential, it also removes risk.
Because each transit uses less water, 14 ships can transit it instead of 12 a day with the same water. That increase in capacity pays for any remaining cost differential.
Furthermore, even more transit capacity can be extracted from it. When heavy rains are more frequent, transits can be increased to about 18 a day. That increase could be made permanent later by adding water storage to the canal.
Alternatively, transits could be increased by at least 50% simply by adding 2 tanks to each of the system’s two-lane lock units. With those tanks added, and when used most effectively, this two-lane system would reduce water-use to 57% of what the planned system will use per transit.
In contrast, there is no way to modify the planned system to reduce its water-use in the future, short of demolishing them and building anew.
Although a two-lane lock system could be designed and built so that tanks could be added in the future, if they were added at the outset they would immediately pay for themselves.
Adding tanks would virtually eliminate the plan to seasonally fluctuate the level of Gatún Lake over a greater range than it is fluctuated today, a change that is needed to increase the supply of water for operating the planned locks.
Eliminating that need would significantly reduce costly dredging.
The 40ft draft depth of the canal’s 35 miles of channel between the Atlantic and Pacific locks must be increased to accommodate 50ft draft ships. However, by not having to drop the lake to the low level the planned system requires, those 35 miles would not have to be deepened an additional 4ft.
Money spent on dredging those 4 extra feet to attain 12 transits a day would be better spent on tanks to attain 18 transits per day – which should also lower the tolls.
Unless eliminated, the plan to increase lake fluctuations will also seasonally force ships that transit the original locks to reduce the cargo they carry by a much larger amount than is the case today, because the bottoms of the original lock chambers cannot be lowered as the lake level drops.
The research shows that the two-lane system would permit canal service and reliability to be significantly improved at a cost about equal to what is currently planned.
By spending the money more effectively, a lower risk and less problematic expansion can be accomplished, offering lower tolls, many more transits, and effectively eliminating the risk of a protracted wait for Post-Panamax ships due to an unexpected lane closure.
None of the alternative systems call for a risky new dike across known faults as the planned new lane requires for traffic to bypass Miraflores Lake. The integrity of that planned dike cannot be guaranteed. Its failure would empty Gatún Lake. That puts the Panama Canal and Panama City at risk. It is a risk that can be totally avoided.
Society, shippers, and operators of Pacific port facilities would be foolish to accept risking an unnecessary dam failure.
Finally, there are additional impacts not accounted for in the present plan that do not arise with the alternative systems.
The planned locks are to operate transiting ships in groups, one direction at a time. Brackish water will be injected into Gatún Lake when ocean-bound ships exit by way of these. This happens today, but only at Gatún Locks. (At the Pacific end of the canal, Miraflores Lake interrupts that salt-injection process.) The excess water in today's canal system falls just short of flushing all the salt reaching Gatún Lake. Consequently, its salt content has been rising very slowly over the last 100 years.
Relative to today’s Gatún Locks, about triple the volume of brackish water will be injected into Gatún Lake when ships exit each end of the canal through the planned locks. Because the planned locks will use less fresh water per transit – 40% of what a regular lock operation uses – the mix of water in them will contain much more salt than what is injected today via Gatún Locks.
As more lake water is used to move ships and less is spilled along with the salt it carries, Gatún Lake’s salt concentration will – without question – rise at a much faster rate than it is rising today.
Obviously, adding salt to the lake does not negatively affect transits. But the Gatún Lake freshwater resource, which belongs to the nation, will be ruined when its salt concentration rises. That loss – avoidable if higher-yield locks are used – has not been taken into account in the costing of the planned single-lane design.
Neither have losses from the predicted eradication of, or irreparable damage to, sea life along both coasts. Too much salt in the lake will permit coastal creatures to migrate across the Isthmus of Panama, which could lead to disastrous consequences, such as stronger species wiping out weaker ones.
If the cost of these damages to nature were to be properly assessed for the expansion as it is now planned, its price tag would rise far above the most costly of any of the alternative lock options noted here, all of which use existing, tried-and-tested equipment and operations, and which more effectively control salt intrusion.
Yet, the current plan continues. The perception is forming among many that the intent may be to deliberately damage Gatún Lake.
Whether that is the case or not, a brackish Gatún Lake will create a huge market for those who have recently acquired rights to the water of many of Panama’s rivers. Those special interests will profit handsomely from selling their water to the population.
Also – with Panama’s greatest freshwater reserve ruined – other special interests that have long wanted to install industries within the canal will be able to do so, without being blamed for polluting that invaluable global resource.
It is clear that building the planned lock system brings no added benefits to society. The damage it will cause in order to benefit third parties is irreparable and unconscionable. Once poorly performing locks are built they cannot be modified later to improve their performance and reduce their negative effects.
Several more effective lock alternatives to those misleadingly promoted as the best and only for the project exist.
An unbiased revision of the plan – before lock construction begins – is imperative to guarantee a truly sustainable development project that optimizes canal services and maximizes capacity and profits, while preserving a critical freshwater reserve for this and future generations.