Flash flooding in Islamabad indicates negligence and poor management by the Capital Development Authority (CDA). In recent decades, flood losses have considerably grown at every scale, from regional to national to continental, due to global weather changes. In the Capital, which lies at the foothills of the Margalla hills, the precipitation is much higher. Flood risk on these foothills is of considerable social relevance, as well as of practical importance.

Recently, we have experienced heavy flash-flooding in the capital city. This flooding not only damaged the property but also caused the deaths of a mother and child, as flood water entered the basement of their house at night in E-11/2 sector. The rear retaining wall couldn’t resist the force of the flood and caved in. This entire strip of houses, roads and commercial buildings is built on a natural course of water.

Islamabad was designed with the anticipation of the next two to three decades of its population growth. The beautiful land profiles and ridges allow for the flow and evacuation of rainwater, naturally, during the monsoon, through a number of clean water streams and channels. Korang stream, along with some other small streams coming from the Margalla hills, has formed from the artificial Rawal Lake in Islamabad. Korang River is the outlet stream of the Rawal Dam.

The E-11 sector was originally exempted from acquisition by the CDA, due to the presence of the Golra shrine. The CDA only acquired a portion of this sector, called the northern strip; this strip was allotted to those displaced by land acquisition in sectors F-11 and F-12. E-11 comprises five co-operative housing societies, developed by private developers. These are , Multi-professional Housing Society, Police Foundation, Federation Cooperative and Medical Cooperative Housing Society.

The Federation Cooperative Housing Society does not have an NOC and the Medical Cooperative Housing Society’s layout plan was rejected. These societies were developed illegally, without any stern action from the CDA. There are a number of multi-storey towers and other commercial buildings constructed on and around this area, on private land that are unplanned and unauthorised. The CDA has been unable to control or impose any limits on these developments. The inaction has resulted in haphazard construction, which threatens the environment and aesthetics of the city.

There were two natural water channels, amongst these, a main waterway (nullah) passed through E-11 sector. This nullah initially became a garbage-dump for the entire sector. Later, the society administration constructed a road over it, covering most of this water way. The main water channel has consequently narrowed at several points, interrupting the flow of rainwater and causing flooding.

Also, some residents have filled up natural streams to expand the lawns outside their houses. Such lawns, in many posh sectors of Islamabad, are mainly on or around waterways. These violations remain unchecked by the CDA. The blocking, rerouting and narrowing of waterways and changes to the natural topography of the land can continue to cause flooding in the future. Natural obstructions to streams, like fallen trees or overgrowth must also be checked promptly.

The beautiful land profiles and ridges allow for the flow and evacuation of rainwater, naturally, during monsoon, through a number of clean water streams and channels.

The CDA is now widening natural water streams in some posh sectors of Islamabad. A large-scale operation to curb encroachments, china-cutting and construction over waterways and illegal construction over mountain fault-lines is urgently required. The CDA must be equipped with an international-standard emergency warning system. Moreover, the damages to the public should be compensated by the authority wherever the loss was due to their failure to enforce laws and regulations. Most of the nullahs in the Capital have become dumping sites for garbage and outlets for sewage lines from the basements of private dwellings in various areas.

These basement sewage outlets are not only sources of diseases and foul odours, they flow back into the property when the natural streams become flooded. During heavy floods, even return valves do not work. Therefore, basement sewage outlets must be sealed in high risk flood areas. Natural streams should be free of garbage and filth to allow proper drainage of rainwater. Increasing public awareness is important to keep these waterways and streams clean.

There are about 20 illegal slums in the federal capital – most of these have grown around these nullahs. These slums are growing rapidly and contribute to flooding. The CDA has failed to relocate or improve the conditions of these slums, where people live in squalour and disease. During the rainy season, these slums are not only badly affected themselves, but also cause hindrance to the flow of water and cause flooding.

Pooling, stagnation and the very slow flow of water due to inappropriate road levels also causes flooding of several roads. This damages the road surfaces and causes great inconvenience to commuters. During the road carpeting drive, the CDA should ensure that water streams and drains remain unblocked.

All the drains and waterways should be cleaned every year before the start of monsoon season. The CDA has failed to play its role effectively in the past. It should now take appropriate measures for the future. The city has to grow outward instead of becoming internally crowded. New areas should be planned better than old sectors to encourage people to settle in new, modern developments with better facilities. This is done all over the developed world.

The Capital Development Authority needs to revise its regulations. Stringent restrictions must be imposed on the bifurcation of large plots, as the city is designed to sustain population growth. Bifurcation not only destroys the facade and overall aesthetics of the city, but also brings a larger population into the same area. This results in more traffic congestion and pressure on service lines.

Heavy fines and the demolition of encroachments must be undertaken in case of violations of these laws. New developments can increase run-off, because of a rise in the numbers of roads, driveways and hard landscaped gardens. These developments should be provided with balancing ponds to compensate for the loss of land for rainwater to soak into. Authorities and developers should be encouraged to avoid too much hard landscaping in new housing societies and to include more green open spaces. These spaces can absorb some of the run-off from roads during heavy rains. Moreover, more trees should be planted.

The original master plan of Islamabad should be analysed by competent professional bodies to see how many paved areas we have added to the city, and how we can balance them with green spaces. The role of the Pakistan Environmental Protection Agency must be clearly defined.

The government must hold the relevant authorities accountable, and ensure that they implement the Islamabad Capital Territory (ICT) Zoning Regulations in all developments, sectors, housing schemes and societies.

The writer is an architect and an honorary adviser to the Tourism Development Corporation of Punjab