Source: World Dredging & Marine Construction
Perhaps one of the leading examples of dredging's direct impact upon a nation's economic growth can be seen in Venezuela. The annual maintenance dredging in Lake Maracaibo and on the Orinoco River has exceeded 70 million cubic meters. Over 70% of the national product of Venezuela comes from petroleum extracted from the zones lying under Lake Maracaibo, thereby creating a heavy traffic in tankers in and out of the Lake.
The Instituto Nacional de Canalizaciones (INC) has the responsibility, as a government agency, to engineer and carry out all dredging and related research and engineering for Venezuela's ocean and inland ports, harbors, waterways, and lakes. INC maintains its own dredging fleet and contracts for supplemental dredging from private contractors as necessary.
INC was formed to manage a new dredging program to deepen the navigable channel of Lake Maracaibo from its average of 11 feet to a new depth of 35 feet. Prior to that the private oil companies operating in Lake Maracaibo had contracted for all dredging.
In addition to the continuing job of channel maintenance in the Lake Maracaibo channel, INC has reclaimed a new industrial area on the eastern shore of Tablazo Bay. At El Tablazo, the state owned Instituto Venezolano de Petroquimica (IVP) is the catalyst for the project—preparing the site, furnishing the facilities for supplying utilities and raw materials, constructing docks and the petrochemical units that will be the cornerstone of the complex.
El Tablazo was developed in two stages. The total investment for the complex was $1.2 billion.
The dredging reclamation was conducted by the dredge "Esequibo", an Ellicott suction cutterhead 20-inch discharge dredger built in 1969 for INC.
In order to expedite the completion of the Tablazo Project, INC decided to purchase an additional dredge, a 36" (914mm) unit and gave the order to Ellicott International of Baltimore. The dredge was named the "Carabobo" after a famous battle for Venezuelan independence. The Carabobo was towed to the site of the Tablazo Project to commence and complete the reclamation for the petrochemical plant. Ellicott furnished a team of four dredging experts to see the Tablazo Project through and to insure meeting the incentive/penalty portion of their contract relative to the performance of the dredge.
Of particular interest is the Hydraulic Laboratory and scale model of Lake Maracaibo, located in Maracaibo City in conjunction with the Central University of Venezuela. All aspects of the dredging operations in the Maracaibo channel and the Tablazo Project are considered in the hydraulic model.
A research project at MIT (Massachusetts Institute of Technology) and at INC conducted a special evaluation program at the Hydraulic Laboratory on alternate means of controlling the Maracaibo channel. The study, entitled "Field Investigations to Determine Sediment Sources and Salinity Intrusion Into the Maracaibo Estuary, Venezuela," focused on several questions concerning past dredging. Among the applications of the hydraulic model to the dredging program in Maracaibo are the evaluation of the effects of landfills such as at Tablazo, drift behavior of silting into the channel from use of the sidecasting boom on the Zulia, and ecological effects of changing the flow water through construction of seawalls or other diversions to normal tidal flows.
The INC organization is efficient in carrying out a dredging project through coordination of research, testing, evaluation and observation of the project itself. INC's engineering, management, research and dredging operations are all within minutes of each other. The financial impact justifying the establishment of the facilities was also there with over 700 million barrels of crude petroleum transported through the Maracaibo channel annually, including over 3,500 tankers entering the lake, or 7,000 traverses of the channel.
INC presents a model for other major ports to consider from the standpoint of having its own hydraulic model and engineering staff in close proximity to the port in those cases where there is constant development and maintenance dredging required. With the emphasis on pollution effects and concern for reclamation altering the behavior of ports, tides and currents, the suggestion applies even more. The Venezuelan Waterways Institute (INC) deserves special recognition for its accomplishments in advancing dredging technology in Maracaibo.
Excerpted from World Dredging & Marine Construction