Floods caused by illegal diversions are drowning Bengaluru

Bengaluru: Home to numerous start-ups and multinational companies, Nagawara in north Bengaluru floods every time it rains. It’s not just office-goers who are affected — pedestrians and motorists using the Outer Ring Road (ORR), a critical stretch connecting Kempegowda International Airport (KIA), also face chaos as traffic comes to a standstill.

These recurring floods have severely impacted Bengaluru’s image as India’s top IT exporter, with social media regularly showcasing scenes of urban paralysis.

A key contributor to the flooding in Nagawara is the missing link in the rajakaluve (stormwater drain) originating from Sultanpalya. A 33-foot-wide drain suddenly takes a sharp 90-degree turn near a Special Economic Zone (SEZ), reducing to just six feet in width. Instead of draining into the Mariyanna Palya bruhat kaluve (Nagawara Kere Kodi in Thanisandra) — a route visible on Google Maps until 2012 — the water gets diverted, leading to floods on ORR and nearby properties.

During a recent inspection, Deputy Chief Minister DK Shivakumar was informed by officials that the 1885 village map showed a continuous drain from Sultanpalya to Nagawara Lake. However, this stretch disappeared in the 1958 survey records. 

Documents further reveal that 27 guntas of B-kharab land — land that could have completed the missing link — were sold by the state government to a private developer in February 2021 for just Rs 5.85 crore, even though the land’s market value was at least four times higher. The sale order was signed by Bengaluru Urban Deputy Commissioner GN Shivamurthy just days before his retirement.

This case is not an exception. Across Bengaluru, the integrity of rajakaluves — essential for flood mitigation — has been systematically compromised due to escalating real estate interests. Despite lacking legal authority, revenue officials have entertained requests to alter the stormwater drain alignments using dubious documentation or misinterpretation of laws, shifting the burden of flood management onto the civic body.

Encroachments and diversions

According to BBMP, Bengaluru currently has 44 flood-prone areas — down from 210 originally identified. The key causes: narrowing and diversion of rajakaluves, encroachments, and incomplete drain works.

While the BBMP has no shortage of funds for the remodeling of drains, its efforts to clear encroachments remain lackluster. Of the 1,486 identified encroachments on stormwater drains, 963 await clearance from the revenue department, and another 345 are yet to be surveyed to ascertain the ownership. Even in cases where the encroachments are confirmed, BBMP engineers have delayed action. Meanwhile, 160 cases remain stuck in court.

Besides this, diversion of rajakaluves is increasingly being used as a legal weapon to bypass established regulations. While laws permit diversion only for roads and pathways, revenue officials often manipulate provisions to authorize realignments of primary, secondary and tertiary drains  without public consultation even though these diversions severely affect local hydrology.

In one such instance, residents of Renaissance Prospero in Byatarayanapura have raised concerns about repeated and unauthorized diversions of a rajakaluve connecting Amruthahalli Lake. Prashanth Rai, president of residents welfare association, shared three orders issued by Bengaluru Urban deputy commissioners between 2017 and 2021, each modifying the drain’s alignment and diverting Nala B Kharab land— including routing it through Park area that was relinquished and vested with the BDA in 2001.

All three orders cited Rule 28(A) of the Karnataka Land Grant Rules, 1969, and Rules 71 and 73 of the Karnataka Land Revenue Rules, 1966. However, none of these provisions legally permit the diversion of rajakaluves. 

“The drain’s alignment was changed repeatedly to facilitate a commercial project, with complete disregard for legal and environmental norms,” Rai said. “Initially, the drain was shown flowing in the middle of said commercial project development plan approved by the BDA in 2013. Then it was rerouted into our residential project site. The recent diversion of B-kharab land and re-routing of the drain has rendered the park area unusable,” he said.

Residents say the diversion has led not only to frequent flooding along the adjacent highway but also to the loss of crucial open spaces within their community. Accessing the documents was a struggle even under the Right to Information (RTI) Act as queries to both Yelahanka Tahashildar and Bengaluru DCs remained unanswered for two years, they said.

A senior revenue official confirmed that there is no legal provision to alter rajakaluve alignments. 

Advocate Vedavyas Shenoy echoed this view, warning of ecological damage. “There’s no provision for drain diversion in the law, yet it happens regularly. The hydrology of these nalas is being altered without public awareness. Even the Revised Master Plan (RMP) is flawed, ignoring drains clearly marked on village maps. It seems tailored to benefit powerful interests,” he said.

Shenoy also raised concerns about intergenerational equity. “Future generations should not bear the brunt of today’s irresponsible decisions. Altering ancient water channels with the stroke of a pen is a reckless act that dismisses their historical and ecological importance,” he said.