The Audit Commission has released the performance audit report on the “Construction of Rainwater Pumping Station and Box-Culvert in Northern Inner Harbour”. According to the statistics, the expenditure on flood prevention and mitigation (including the prevention of flood and the drainage of stormwater) from 2008 to 2020 reached around 1.47 billion patacas. The Audit Commission noted that, in addition to the completed project of rainwater pumping station and box-culvert in the northern area of the Inner Harbour (hereinafter referred to as Inner Harbour North Pumping Station) in mid-2021, the Government of the Macao Special Administrative Region is planning to start a series of flood prevention and mitigation projects, among which the “Inner Harbour South Pumping Station” is progressing on schedule. Therefore, the Audit Commission conducted a review on the construction of the Inner Harbour North Pumping Station, hoping that the audit results could be taken as a reference for public departments that carry out similar projects in the future.
The audit report states that the construction of the Inner Harbour North Pumping Station proposed by the Civic and Municipal Affairs Bureau (hereinafter referred to as IACM) in 2010 was initially expected to be completed in 2014. However, IACM had to choose a new site for the Pumping Station due to the opinions on heritage conservation and the use of the maritime area raised by the relevant departments, which resulted in the delay of the public tender to May 2018. The contract was awarded in the amount of 109,448,716.50 patacas, and the construction was finally completed in 2021. The Audit Commission reviewed the process of determining the rainfall intensity recurrence interval for the drainage system of the Inner Harbour North Pumping Station, and found that IACM had neither consulted the Land, Public Works and Transport Bureau (hereinafter referred to as “DSSOPT”), nor conducted the relevant studies on the selection of the drainage standard, but only submitted the construction plan to DSSOPT for approval. Furthermore, about the report and justification summitted to the superior regarding the delay of the works, the Municipal Affairs Bureau (hereinafter referred to as IAM) stated that because of the lapse of time and personnel turnovers, it was unable to provide the relevant documents.
On the other hand, in accordance with the current legislation, DSSOPT has the responsibility to monitor the compliance with the norms in regard of the rainfall intensity recurrence intervals for drainage systems. However, despite being aware, through two reports in 2012 and 2017, that it was recommended the adoption of a 1 in 20-year rainfall intensity recurrence interval for the drainage system in the Inner Harbour area, DSSOPT besides not having sent these reports to IACM for their knowledge, it did not give any opinion in regard of the adoption of a 1 in 10-year rainfall intensity recurrence interval, when assessing the construction plan for the Inner Harbour North Pumping Station, even it got the approval of the Chief Executive to adopt the abovementioned recommendation of a 1 in 20-year rainfall intensity recurrence interval in March 2017.
The surrounding area of the site selected for the construction of the Station is at the lowest elevation point in Macao, and the rainwater from the north of the Inner Harbour would tend to flow into this area due to the water flow characteristics, and thus, requires a high drainage capacity. The construction of the Inner Harbour North Pumping Station mainly included the replacement of drainage pipes in the downstream district, the construction of a box-culvert and rainwater pumping station, as well as the closure of coastal rainwater outlets. After the works of the Inner Harbor North Pumping Station, DSSOPT started to plan for the construction of the Inner Harbour South Pumping Station. Since the Inner Harbour North Pumping Station did not reach the drainage standard, DSSOPT determined that in the construction of the Inner Harbour South Pumping Station, a new bypass drainage pipe shall be built to divert rainwater from the north to the south of the Inner Harbour and expand the pumping capacity, as complementary measures.
It is also mentioned in the report that, despite the construction of the Inner Harbour North Pumping Station was completed at the end of May 2021, a rainstorm on 1 June 2021 caused serious flooding in the northern area of the Inner Harbour. Hence, IAM analyzed the cause and reached the conclusion that the water levels set for starting and stopping the pump were not properly adjusted, the capacity of the old drainage pipes was insufficient and there was accumulation of rainwater coming from other areas. In addition to the reasons pointed out by IAM, the Audit Commission also found potential insufficiencies in regard of the drainage capacity of the new system. After conducting a data analysis of the rainfall, the water level and the operation of the Inner Harbour North Pumping Station registered on that day, it was found that when the rain was not heavy and the box-culvert was not full in the early hours of the rainstorm, the rate at which the replaced drainage pipes discharged rainwater into the box-culvert was lower than the rate at which rainwater flowed to those drainage pipes, indicating that the drainage capacity of the newly replaced drainage pipes was also insufficient.
In October 2019, the Macao SAR Government released the “10-Year Plan for Disaster Prevention and Mitigation in Macao (2019-2028)”, in which a study conducted by experts showed that among the capacity to response to 56 types of emergencies, the capacity to flood prevention and mitigation in infrastructure ranked third to last, so the construction of the relevant infrastructure to prevent flooding should be a priority. However, it can be learnt from this audit that the Inner Harbour North Pumping Station was not built for the purpose of meeting demands in the long term, failing to maximize the effect of public funds invested. Each infrastructure investment involves a large amount of public funds, and during the construction process, there are often road excavations and closures for long periods of time, affecting the daily life of the residents. If the infrastructure cannot meet the expectations after completion, it would often be difficult to demolish and rebuild. Otherwise, it would not only waste the public funds, but also cause further disturbance to the public. It should be highlighted that the complementary measures taken at the Inner Harbour South Pumping Station can only alleviate the problems in the short-term, but cannot change the fact that the standard set up for the drainage system of the Inner Harbour North Pumping Station is insufficient, failing to satisfy the needs of city developments in the future.
As mentioned in the general comments of the audit report, in the Policy Address for the fiscal year 2010, the Macao SAR Government had already set out the objective of committing its greatest efforts to solve the problem of flooding in the old districts. With regard to planning, it was found that IACM, DSSOPT and the Cultural Institute took several years to reach a consensus on the location of the construction works, which caused the delay of completion of the project originally scheduled for 2014 to 2021. This reveals that the authorities failed to strictly implement the project according to the schedule, and thus not only prevented a quick resolution of flooding problem, but also affected the comprehensive benefits of the project. In addition, as a result of the delay, inflation had increased the construction and administrative costs. With regard to interdepartmental cooperation, it was found that, in respect of the determination of the rainfall intensity recurrence interval to be adopted for the drainage system and its respective technical specifications, there were lack communication between IACM and DSSOPT. During the planning process, they adopted an attitude of doing their own way and lack serious consideration in the selection of drainage standard. As for the technical problems related to the management of public funds and public safety, they neither planned nor took responsibility proactively, resulting in missed opportunities to optimize the related works.
Solving the flooding problem has been the government’s commitment clearly stated in the Policy Addresses over the years. However, the problems revealed in this audit shows the inadequate coordination and improper management of the relevant departments, which not only delayed the implementation of the policies and measures of the SAR Government, but also failed to respond, in due time, to the long-standing demands of the society. Therefore, the relevant departments should seriously conduct a thorough review, and formulate effective measures to resolve the problems reflected in this report, so that the infrastructure project can achieve the expected results.
The audit report was previously submitted to the Chief Executive, and the public can download the full text of the report from the website of the Audit Commission (http://www.ca.gov.mo), while paper copies are available at its Office during office hours.
