Wednesday June 07, 2023

Tackling Karachi’s floods

September 13, 2020

Urban drainage infrastructure is almost entirely built underground. Being out of sight, it is a lucrative avenue to illegally pocket millions. Avenues for making money are aplenty, first in the planning and design phases and later in the quality of materials used for construction.

One would be living in a fool’s paradise to expect funds allocated to improving urban drainage to be utilized honestly and judiciously by Karachi’s authorities. Keeping the authorities honest will require Karachiites to get involved and oversee the process from planning through to construction.

The best way for the people of Karachi to do this perhaps would be to set up a non-governmental organization (NGO) with a mandate to oversee the work of the authorities.

The NGO would do this by demanding transparency in bidding processes; ensuring international standards are complied with in design and construction; exert sustained pressure on relevant authorities to continue implementing plans after life goes back to normal; and regularly report progress to the residents of Karachi.

The NGO should comprise well-qualified engineers, lawyers and academics who specialize in planning, engineering and policy-making in water sensitive urban design (WSUD). They should be appointed on a full-time basis and paid highly competitive wages.

The government should allocate some funds to help Karachi’s people set up and run this NGO. Private industry in Karachi should also come forward in a big way to foot the bill.

Without vigilant oversight by Karachi residents, who is going to ensure, for example, that the firm responsible for construction doesn’t procure substandard material and pocket millions of rupees in the process?

Who will ensure the quality of the water-tight joints between the pipes? Concrete pipes are made in factories in small lengths to optimize transport and handling. These are then joined together to form the entire length of a pipeline. The joint between two pieces of pipes is sealed using a special material that ensures the joint remains water-tight for the entire intended life of the pipe (about 30 years).

Who is going to ensure the contractor does not use a substandard material for the joint pocketing millions of rupees on hundreds of joints across thousands of meters of pipes?

A substandard joint will not possess the structural properties required to withstand high stresses created by small movements in pipes as they settle on their foundations. This will result in leaks through the joints which will erode soil material supporting the pipes. As the support goes, the pipes will collapse leaving dangerous sinkholes in the ground.

The purpose of delving into such detail is to emphasize the scale at which corruption can take place in drainage projects destining millions of rupees of investment to failure right at the start. Even if Karachi’s authorities had the will, they certainly do not have the capability to ensure the level of quality control required.

Let’s turn to policies and regulations, an integral requirement of any effective urban drainage plan.

One of the cornerstones of urban drainage regulations is the requirement for new industrial, commercial and residential developments to ensure the maximum rate of rainwater flow from the new development does not exceed the pre-development maximum flow rate from the same area.

Prior to roads, houses and commercial buildings being developed, the land in its natural state is covered by soil and vegetation. Such natural surfaces are permeable and able to absorb a significant volume of rainwater at the initial stages of a rainfall event. The remainder that is not absorbed flows into drains and is usually within the latter’s capacity to carry away without overflowing.

When new developments add roof-cover and convert permeable surfaces to roads and concrete pavements, these impermeable surfaces do not absorb any rainwater. All rainwater in this scenario travels to surrounding drains at a faster rate and a larger volume resulting in overflowing of drains and urban flooding.

How do developments ensure their post-development peak-flows remain equal to their pre-development peak-flows? They do so by reserving a significant area of land within their development for artificial detention ponds and green areas with permeable surfaces in the form of parks, sports grounds and green verges. Developments that have already been built are required to retrofit components like bioswales and rainwater tanks into the development.

Who in Karachi is going to check that the DHAs, Bahria Towns, KDAs, Model Colonies, and various ‘abadis’ and ‘goths’ are reserving space for detention ponds and green areas instead of cashing in every last inch of space?

Given these intricacies and the state of administration and governance in Karachi, it should be apparent to Karachiites that they have no choice but to get involved in the entire process of rebuilding urban drainage and remain vigilant throughout. And therefore, an NGO as suggested at the start of this piece seems like the only sustainable manner of doing so.

In whatever form they choose to organize themselves, top on their list of demands should be that an international engineering firm should be engaged to prepare a drainage master plan for Karachi. The selected firm should have experience preparing similar plans for cities like Dubai, Jakarta, Manilla, Kuala Lumpur or Singapore.

Karachi must also demand that all tender documents prepared for engaging firms for planning, then design, and then construction, must be prepared with input from the public and made available for comment for at least 30 days prior to being released to the market.

The evaluation criteria for selection of tenders must give more weight to quality than cost. Any prohibitive or limiting local regulatory requirements, such as compulsory accreditation with the Pakistan Engineering Council, should be lifted to ensure a level playing field for international firms.

Bids submitted should be made available for public evaluation and the evaluation carried out by the authorities must also be made available for public scrutiny.

Another important demand would be for the authorities to engage an international firm as the Owners Engineer (OE) for both the design and construction phase of any urban drainage project. OEs are engineering firms hired to provide oversight and technical expertise to protect their client’s interests by ensuring the designers and build contractors adhere to project specifications. OEs can also fill resource gaps in government departments during the life of the project.

A successful and well recognized example of this arrangement was the design and construction of the Lahore-Islamabad Motorway. Back in 1992, the National Highway Authority (NHA) of Pakistan hired a renowned international engineering firm as an OE to carry out design review, contract administration, construction supervision and quality control for the construction of the motorway.

Not only did the OE ensure the project became a benchmark for motorways designed and constructed in the country ever since, many technical firsts during the project played a significant role in the modernisation of the NHA. For example, it was the first time that Civil3D Software and simulations were used for design on a highway project in Pakistan. It was also the first road project in the country to be completely supervised using software. It changed the overall culture of the NHA by introducing the latest technologies of the time.

Like the standards that residents of other vibrant metropolitan cities in Asia enjoy, the residents of Karachi deserve nothing less than state-of-the-art infrastructure. But like these cities, Karachi needs to bring in international engineering firms and let the city and its authorities benefit from the knowledge and technology they possess.

The PM’s historic announcement of Rs1,100 billion for Karachi has the corrupt in a frenzy in anticipation of the loot and plunder ahead. It is in the hands of Karachiites to organize themselves and stop them.

The writer is a water and environmental engineer working in irrigation in Australia.


Twitter: @znafridi