Mohali storm drainage system needs urgent overhaul to tackle waterlogging: MC report

Unable to handle no more than 25 mm of rain per hour, leading to a waterlogging nightmare after every rainfall, Mohali’s current storm drainage system needs urgent upgrades, according to a report prepared by the municipal corporation (MC).
Highlighting the problem areas, mostly low-lying areas in the city, and solutions to tackle the flooding, the report has been prepared by a Noida-based consultant hired by the civic body.
Though now withdrawn, monsoon posed significant challenges for residents for the past three months, with overflowing drains, inundated roads and rainwater entering homes in low-lying areas each time it rained.
Despite substantial investments in desilting and enlarging storm drains, the civic body failed to alleviate the persistent waterlogging issues.
The existing drainage network in Mohali includes a series of natural streams and man-made drains, which are the primary conduits for stormwater runoff.
During periods of intense rainfall, these drainage channels often overflow, causing flooding in low-lying regions. The situation is exacerbated by inadequate drainage infrastructure and unplanned urbanisation.
The report identified the areas most affected by the monsoon deluge: Phase-1 Diplast Chowk to Mohali village; LIG flats and Bawa White House light point to Mandi Board light point in Phase 11; Phases 9 and 10; Phase 4, near Bougainvillea Park; Phase 5; Sector 70, Sector 71; Airport Road from Gurdwara Singh Sheehan to Cheema Boiler; Phase 3B1, Phase 3B2; Phase 7, Sector 78-79 dividing road and Sohana village.
Phase-1 Diplast Chowk to Mohali village
As per the report, the main causes of flooding in the said area are silting in stormwater drains, discrepancies in road elevation as the elevation of Franco Road is higher compared to Mohali village road, causing flooding in low lying areas of Mohali village. Moreover, the surface runoff from Chandigarh and inadequate size of stormwater pipelines (1,400mm diameter pipe) are not adequately sized to handle the current volume of rainfall.
The report highlighted solutions like regular maintenance and desilting of stormwater drains by using hydro-vacuum excavation techniques to effectively remove silt and debris. The other solutions include elevation adjustments of Franco Road and road levelling. As per the report, if lowering Franco Road is not possible, MC can consider re-grading the surrounding land to create effective drainage paths. Expansion and upsizing of storm water pipelines besides water discharge by mechanical pump to the nearest drain by laying pipeline adjacent to road are the other recommended solutions.
Phase 4, near Bougainvillea park
With similar issues across the city, the report suggested that to effectively mitigate flooding near Bougainvillea Garden in Phase 4 (Sector 59), measures, including regular cleaning of drain pipelines, road elevation adjustment, enhanced stormwater management infrastructure, upsized and dual drainage systems, integrated smart water management technologies and active public involvement, will improve drainage efficiency, manage surface runoff effectively and significantly reduce flood risks during the monsoon season.
Similar solutions have been highlighted for Sector 71 and Mataur village
Phase 5
Flooding in Phase 5 (Sector 59) despite the presence of an additional open channel drain has been attributed to heavy rainfall. The open channel drain was originally designed based on historical rainfall data, which is not adequate for the current intensity and frequency of heavy rainfall. Other factors of flooding include accumulation of debris, silt and garbage, blocking the flow of water in the drainage channel, reducing its capacity and efficiency.
The report suggested that a combination of improving drainage infrastructure, regular maintenance, better urban planning, and ensuring community awareness and participation in keeping drainage systems functional will help to resolve waterlogging in Phase 5.
Rising population straining storm drainage system
According to the report, the current population of Mohali, according to the latest census, is approximately 3,50,000. The population is projected to increase significantly,
reaching around 5,00,000 by 2030 and potentially growing to 7,00,000 by 2050, representing a 100% increase in the next 25 years.
The city, being a part of a rapidly urbanising region in Punjab, is experiencing substantial growth in both population and infrastructure development. With more impervious surfaces like roads and buildings increasing stormwater runoff and changes in land use altering natural drainage patterns, there is a pressing need to upgrade and expand the existing storm drainage system, the report suggests.
‘Drainage system revamp needs ₹100 crore’
“Around ₹100 crore are required to upgrade the entire city’s drainage system. With major urban development and increasing population in Mohali, the entire drainage system needs a revamp. Thus, we have sent proposals to the local bodies department and also requested GMADA to release our pending funds of around ₹35 crore to allow us to complete the project before next monsoon. If funds are allotted, Mohali will not face waterlogging issues for the next 50 years,” said Amarjeet Singh Sidhu, Mohali mayor.