Deteriorating flash floods in Guwahati is a wake-up call for expediting the implementation of the sponge city solution initiated by the Guwahati Metropolitan Development Authority. The challenge, however, remains to ensure that the sponge city project doesn’t turn into an elephant in the room after the rainy season ends. While the sponge city can help Guwahati soak the excess rainwater and channel it efficiently, without the soil conservation on the city’s hills, its effectiveness against sudden and heavy rainfall is likely to remain fragile. Rampant encroachment on the city’s hills has led to the recurrence of topsoil erosion, and during heavy rainfall loose earth and debris washed away by rainwater quickly fill the drains along the foothills. If the capacity of drains gets reduced due to the choking of their channels, then the sponge city ponds cannot function efficiently as a rainwater buffer. Mere rejuvenation of the city’s water bodies, therefore, under the sponge city project cannot provide a lasting solution if the capacity of the entire city to soak, store and drain rainwater is not enhanced. With hills all around, rainwater flowing down the hills to the plains is a natural process. The solution lies in removing obstruction and conserving the green cover of the hills so that major part of rainwater gets retained by the trees and absorbed by the soil and the excess surface water runoff is milder in force and does not bring soil with it while flowing down to the plains. Massive and unplanned encroachment in the hills makes it impossible to restore the natural flow, but combining eviction in forest areas with massive tree plantation in denuded patches can significantly check landslides and topsoil erosion. An effective sponge city concept needs to be anchored on the concept of converting the roads and streets into temporary water storage and corridors so that rainwater does not accumulate on the streets and gets into a water conveyance system through seepage points all across. However, construction of such a durable solution involves a massive cost which is not possible for a resource-deficit state without massive central government funding and externally aided project spending. Past experiences show that when it comes to the implementation of projects of such a mega scale, time and cost overruns often reduce the projects to being unviable as data used for articulating the Detailed Project Report becomes obsolete due to such delay and the solution fails to work. Long and undue delay in the execution of smart city projects in the city lays bare the harsh reality of the state lacking the institutional capacity to execute projects of mega-scale on time. The implementation of the Guwahati Master Plan missing several deadlines is a grim reminder of the chronic weakness of urban governance and project management. Transparency in Guwahati’s sponge city planning and execution is essential to secure citizens’ support for raising revenue in exchange for credible safeguards against urban flooding and to fund the recurring cost of repair and maintenance. Wider dissemination of project details can facilitate informed discussion among city residents, and domain experts among them can come up with the required solution and suggestions for design modification so that the citizens develop ownership of the sponge city and other development projects which are intended to make city life liveable and sustainable. Currently, the city residents are clueless of the solutions that the authorities have initiated for finding a sustainable solution to the deepening crisis of flash floods. Therefore, when they get stuck for hours in traffic congestion triggered by waterlogging on the main thoroughfares while returning home after a day’s work or while going to the office and other duties, the criticism over the failure of the city authorities to address the recurrent problem casts a long shadow over informed public discourse on finding durable solutions. The recurrence of flash floods with rising intensity threatens to rapidly erode the city’s capacity to manage urban flooding and push it to chronic vulnerability. The deepening crisis demands that the city authorities undertake enforcement of their land-use regulations without delay and deal with any deviation from the Master Plan regulations with an uncompromising firmness. The city can least afford any further tampering with its natural ecosystem services and must prioritise their inspection and restoration. The sponge city project cannot be dragged on endlessly, offering the residents only the hope of a sustainable relief from recurring waterlogging without delivering results. The deepening crisis calls for fast-tracking its execution but in a transparent manner to keep informing the citizens about the intended outcome and about the role they must play for successful operationalisation. Expeditious implementation of the central government-funded project of low-cost urban housing projects is also essential to curb further encroachment of the city hills and to gradually relocate existing unauthorised occupants, thereby strengthening the city’s resilience against urban flooding through planned execution and a comprehensive sponge city project.