CDMP Progress Bulletin

Dominica Coastal Infrastructure Rehabilitation

Bulletin Date: December 1999

Following hurricanes Luis and Marilyn in 1995, the Government of Dominica requested assistance from USAID and CDB for rehabilitation and reconstruction of key sections of this sea defence system. The Caribbean Development Bank (CDB) approved a loan of $2.3 million and USAID provided $500,000 under a Limited Scope Grant Agreement. The USAID agreement stipulated that CDB and the Government of Dominica work with the CDMP to assess the storm hazard risk, appropriate for the design of these structures, and include storm hazard damage mitigation measures in the engineering designs for infrastructure rehabilitation and reconstruction. Since the coastal defences in Dominica require regular design, construction and maintenance, it is appropriate for a local engineering capability in this field to be developed and strengthened.

Project Objectives and Original Design

The overall objective of this project is to assist the Government of the Commonwealth of Dominica (GCD) in setting design standards for the coastal rehabilitation work to be financed under the CDB loan. A long-term objective is to strengthen local capacity to design, build and maintain cost-effective sea defences. A secondary goal of this project was to develop a model for the incorporation of storm hazard damage mitigation into the design of large public infrastructure development projects. By incorporating realistic estimates of storm hazard into infrastructure design, the Government of Dominica will minimize future expenditures on its coastal defences.

Components of this infrastructure rehabilitation project include: analysis of storm surge and wave impact under various storm scenarios, a detailed geotechnical investigation of rehabilitation sites, and definition of design criteria sufficient to provide facilities able to withstand storm impacts and engineering design for coastal defence rehabilitation work. A pre-bid workshop for selected engineering firms to present and review the designs for the sea defence rehabilitation was planned, as was a more general workshop for coastal planners and emergency managers to discuss coastal storm hazard assessment, coastal land use and emergency preparedness. Because the need for coastal defence repair work is perennial, an emphasis was to be placed on developing the necessary technical skills in Dominica, where possible.

The initial intention was to assign the nine sites forming part of this project to the three local consulting engineering firms then practising in Dominica. Recognising that none of these local firms had the in-house expertise in Dominica to provide all of the functions required for this assignment, the intention was for the CDMP to provide a “supervising” consultant to fill the gaps. This was done to maximise the use of local resources while maintaining high standards, and would transfer technology and build the local and regional capabilities for similar assignments in the future.

Specifically, CDMP consultants would:

• analyze the wave and storm surge hazard at the selected sites;
• develop the soils investigation program;
• determine the design criteria for wave heights, storm surge, wave forces and scour depths;
• assist the local consultants with the development of conceptual designs;
• conduct a training workshop for the local consultants, public works department engineers and other regional engineers where the procedures for determining the special design criteria and the conceptual designs would be explained;
• review the detailed designs and other contact documents prepared by the local consultants;
• assist with the special coastal-engineering aspects of the procurement process for the construction contractors; and
• provide an oversight during the construction phase.

Project Modified Design

Regrettably, the procedures described above were not pursued and the selection of consultants was carried out through open competition among all eligible CDB countries. In those circumstances it was not possible for any one of the local firms to be selected in its own right. The successful consultant team was a joint venture of a US-based firm and a Trinidad and Tobago firm.

Because of the changes in approach, and after discussions with the Government of the Commonwealth of Dominica (GCD) and the Caribbean Development Bank (CDB) it was decided to limit the input of the CDMP to:

• analyze wave and storm surge hazard at the selected sites;
• develop the soils investigation programme;
• determine the design criteria for wave forces and scour depths;
• review the results of the site-specific hazard assessments, combined in the Design Stage I report prepared by the joint venture; and
• participate in the pre-bid meeting.

CDMP contracted Watson Technical Consulting to study the wave and storm surge hazard, and Consulting Engineers Partnership (CEP) with specialist sub-consultant Westmar to carry out the remaining tasks.

Project Implementation and Outcomes

• Preliminary Site Visit: to observe site conditions and prepare a soils investigation programme. March 1996.
• The Soils Investigations Program: submitted by the CDMP to the GCD consultant in August 1996. The GCD consultant contended that soils investigations were outside their terms of reference, causing significant delays in project execution. In an attempt to move the project forward, a meeting was convened at the CDB in October 1997. At that meeting a minimum-acceptable soils investigation program was agreed upon. This was largely completed by the GCD consultant by March 1998.
• Storm Surge, Waves and Off-shore Bathymetry: This information was developed by Watson Technical Consulting and submitted to the CDB, the GCD and its consultant, and the OAS in November 1996.
• Design Criteria for Wave Forces and Scour Depths: After receiving the geotechnical and topographic input from the GCD consultant, the CDMP submitted the design criteria to the GCD and the CDB in May 1998.
• Review the Design Stage I Submission of the GCD consultant: A Design Stage I report was issued by the GCD consultant in January 1998. Review and comments were sent to GCD and the CDB in May 1998.

As of the end of 1998, the recommendations contained in the review were not acted upon by the GCD consultant. Since no further contributions can be made by the CDMP, it was decided to terminate the project in 1998.

Conclusions

The prime role of a review consultant is to reduce the incidence of errors or unsatisfactory designs and construction. It is not so much a question of one engineer checking on another. It is more a question of a review consultant assisting a design consultant in achieving a better and more reliable project by providing independent assessments of the work. Obviously, there will be cases where deliberate sub-standard work and sheer incompetence are present. In such cases the involvement of a review consultant would be vital for the protection of the client and in providing security for the funding agency and insurance underwriter.

In the case described above, an impasse was reached between the review consultant suggested by the funding agency and the design consultant hired by the client. This led to an overall frustrating exercise that lasted nearly 3 years, and did not lead to a satisfactory conclusion.

To achieve better results from this process of independent design reviews in the Commonwealth Caribbean, the following guidelines are suggested:

• Hold discussions between the client, the funding agency and other relevant parties at the initiation of the project to examine the intentions of the exercise and to determine the scope of the service.
• Provide the prospective design consultants with the terms of reference of the review consultant as part of the description of the project for which they are proposing their services.
• Hold discussions between the selected design consultant and the review consultant at the start of the assignment of the design consultant. These discussions would be the opportunity to agree on detailed timetables for submissions and reviews and on the modus operandi.
• Provide the client with formal reports of the conclusions of the reviews, however do not involve the client in a detailed account of review discussions.

The CDMP is convinced of the need for peer review as a means for reducing the incidence of failures of infrastructure, in the Caribbean and elsewhere, especially as a result of natural hazards.