Delhi rules out floodwater reservoirs, pushes for upstream Yamuna dams

Delhi's I&FC department finds floodwater reservoirs unfeasible due to siltation and land costs.

New Delhi: The irrigation and flood control (I&FC) department found that creating reservoirs to store excess floodwater during monsoon in Delhi is not feasible, senior officials said, citing high siltation level during flooding cycles, poor land availability and very high land rates as key impediments to the project.

Flooding of a locality near the Yamuna. (HT Archive)

The I&FC, instead, batted for expediting work on dams upstream, in Himachal Pradesh and Uttrakhand, for better regulation of river flow and moderation of floods in Yamuna.

A senior government official, who did not wish to be named, said a joint management committee under the chairmanship of Central Water Commission chief sought to improve river management and flood mitigation in Yamuna between Hathnikund and Okhla in the aftermath of the 2023 floods.

“The joint committee had recommended study to be carried out for development of reservoirs for flood moderation... Many underground reservoirs have been developed in Japan and other countries as a buffer during heavy rainfall period where the water can be used in lean period. We have found the proposal to be non feasible, both in terms of technology and economically,” the official said.

In its report dated February 21, a copy of which was accessed by HT, the I&FC department said, “Due to non availability of sufficient land and due to excessive silt load of river and huge financial investments this may not be feasible in Delhi area. However there are proposals underway for construction of dams in upstream areas like Renukaji, Kishau, Lakhwar-Vyasi and Hathnikund.”

The official cited above said that the pilot project carried out in Palla floodplains has also not been taken forward due to siltation and heavy costs.

The pilot

The previous government in the state, in 2019, initiated the Palla floodplain project to tap excess water during the monsoon flooding cycles. The project targeted capturing excess monsoon rainwater through a series of excavated ponds to increase water availability.

Over the past four years, the impact of such ponds was studied across a 26-acre site on the floodplains, near Sangarpur.

The Palla floodplain runs across 20–25 kilometres of the Yamuna’s length north of Wazirabad and contains aquifers that are perennial sources of drinking water for Delhi. The previous government estimated that the pilot reservoir led to groundwater recharge of 2,280,000 cubic metres in 2023 alone. However, the project was not expanded to cover 1,000 acresat full scale due to high costs and high silt levels.

Dams

Three dam projects on the Yamuna and its tributaries have been revived by the Centre after decades: Lakhwar (in Uttarakhand), Renukaji (in Himachal Pradesh) and Kishau (On the Uttarakhand and Himachal Pradesh border). These have been envisaged to improve water availability, rejuvenate the Yamuna and improve flood management.

Once completed, the Lakhwar dam will supply 135 million gallons per day (mgd) of water to Delhi. The Renukaji and Kishau projects have the potential to provide the city with 275mgd and 372mgd of water respectively, improving e-flow and reducing dependence on erratic seasonal flows.

The Lakhwar project is the largest of the three and involves the construction of a dam on the Yamuna near Lohari village in Dehradun. Its construction was suspended in 1992 due to funding constraints.

The Kishau multipurpose project, planned on the Yamuna’s tributary Tons, will feature a live storage capacity of 1,324 million cubic metres. The project faced delays due to interstate disagreements and financial hurdles.

The Renukaji dam, conceived as a storage project on the Giri river in Himachal Pradesh’s Sirmour district, will involve a 148-metre-high dam.

The construction of the Lakhwar dam is underway, Renukaji is in tendering phase, while Kishau is in interstate agreement stage, the official cited above said, estimating that they may be commissioned between 2031 and 2033.

A fourth proposed dam was envisioned after the 2023 floods at Yamunanagar, 4.5km upstream of the Hathnikund barrage, at a cost of ₹6,134 crore.