VIJAYAWADA: On August 31, as part of their routine procedures, officials from the irrigation department shared notifications about rising floodwater levels in the Budameru and Krishna rivers via WhatsApp groups for administration at both mandal and district levels.
The alert highlighted the increasing floodwaters and the operation of the Velagaleru Head Regulator gates. However, the officials did not anticipate that heavy inflows exceeding the capacity of the Budameru Diversion Channel would lead to breaches. This caused the Budameru river to revert to its original course overnight, flooding half of Vijayawada within a few hours. This occurred amid torrential rains that had been affecting the region since Friday night.
A senior official explained that typically, IMD alerts from the CWC are used as warnings for rivers and streams. The rainfall and flood conditions in upstream catchment areas are assessed to estimate when the flood might reach the Prakasam Barrage or other locations, guiding decisions by the revenue department. 
However, sudden flash floods from unexpected heavy rains in upland and hilly areas can be challenging to predict. For smaller rivers like Budameru, flood assessments rely on IMD forecasts and local rainfall data. On August 31, a flash flood upstream of the head regulator occurred, with several tanks in the catchment area breaching due to intense rainfall. Flash floods were also reported in streams feeding into Budameru, such as those in G Konduru, Mylavaram, and A Konduru.
Although an increase in floodwater levels up to 30,000 cusecs was anticipated, and officials were instructed to lift the regulator gates, the floodwater exceeded the Budameru Diversion Channel’s capacity, causing the bund to breach. This led the floodwater to flow back into the rivulet’s original course. Historically, during the 1964 Budameru flood that submerged northern parts of Vijayawada, 24,000 cusecs of water was discharged upstream of Velagaleru. At that time, the floodplains of Budameru mostly consisted of fields and a few minor settlements.
Anticipated Breaches and Flooding: Andhra Pradesh Special Chief Secretary Sisodia stated that breaches in Budameru could not be anticipated.
To mitigate future flooding, a head regulator was built at Velagaleru village with a capacity of 7,500 cusecs, and the original course of Budameru was retained at 16,500 cusecs. By 1991-92, the diversion channel's capacity was increased to 15,000 cusecs, with the original course capacity reduced to 9,500 cusecs. However, rapid urbanization has led to the occupation of floodplains and encroachment on flood banks, reducing the discharge capacity of Budameru’s original course through Vijayawada to less than 3,000 cusecs.
“There is an urgent need to implement the proposed increase in discharge capacity to 15,000 cusecs to flood-proof the city,” said an irrigation expert.