Jalpaiguri: Karala River rain gauge alerts under review

Jalpaiguri: The rain gauge system installed in the Karala River has caused confusion due to the river’s shallow depth, leading to inaccurate flood warnings. To resolve this, the Irrigation department has initiated dredging to determine the river’s actual depth and improve water level measurements.

Despite ongoing monsoon activity, the Karala River remains shallow, often triggering overflow alerts at minimal water levels. The automatic rain gauge, installed a year and a half ago, has failed to provide accurate red and yellow warnings. To ensure precise flood assessments, the district administration plans to deepen the riverbed. Following the 2023 monsoon, an advanced water level recording system was installed on Netaji Subhash Bridge, with a sensor monitoring the Karala River. While it detects water levels during heavy rainfall, the river holds barely knee-deep water in dry months, leading to inconsistent readings. According to irrigation officials, this is the first time the Karala River’s water levels are being monitored using such technology.

The recorded data is transmitted to the state Irrigation department’s control room in Kolkata via Supervisory Control and Data Acquisition (SCADA). However, due to the river’s low water-holding capacity, last year’s data transmission was unreliable, causing false alerts at low levels. Officials believe dredging is essential to establish accurate flood warning thresholds.

The rain gauge station monitors flood risks in Maskalaibari, Netaji Para, Nij Math, Shanti Para, Pavitra Para, Babu Ghat and Samaj Para — spanning from the District Hospital through Subhash Bridge to the Teesta-Karala estuary. However, effective monitoring depends on increasing the river’s depth.

District Magistrate Shama Parveen stated: “We will soon begin the tender process to engage an expert firm for dredging the Karala River.”

Krishnendu Bhowmik, Chief Engineer of the Northeast Division of the Irrigation Department, added: “The automatic water level recorder has been installed, but unlike other rivers, the Karala previously lacked a rain gauge station. Currently, there is no established parameter for issuing yellow or red alerts at specific water levels. However, this year’s data will provide crucial insights for setting proper flood warning thresholds.”