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The Meenvallom Small Hydel Project is executed by the District Panchayat, Palakkad through Palakkad Small hydro Company Ltd, a company constituted by District Panchayat registered according to the Companies Act 1956 at the Registrar of Companies, Ernakulam, Kerala.

The 3 MW (2 x 1.5 MW), 8.47 MU (Million Units) Meenvallom Project situates in Palakkad District, Mannarkkad Block and Karimba Panchayat. The Project is a run off the river scheme and constitutes a 6.5 m height and 59.8m length small weir in Thuppanad River which is a tributary of Thootha puzha which itself is a tributary of Bharathapuzha. The Thuppanad River is a perennial stream. The impounding water at the reservoir is brought through a 582 meter length penstock pipe to run two Pelton wheel horizontal turbines and two numbers 1500 KW, 3.3KV, 50 Cycles/second synchronous Generators housed at a power house at the bank of the same stream. The 3.3KV generated supply is stepped up to 11KV and is transmitted to nearby 110KV substation at Kalladikode. The tailrace water after generation is allowed to flow to the same river.

The weir, the penstock, the power house and the tail race are situated in reserve forest land to an extant of 1.15 Ha coming under Mannarkkad Forest Division. 3KM approach road has been constructed by District Panchayat through people participation and 3.5 KM 11 KV line has been constructed under deposit work for transmission of generated supply.

The Project was synchronized to the KSEB grid on 17.06.2014 and commissioned both Machines on 29.08.2014 by Sri Arayadan Mohammed the Hon. Minster for Electricity, Government of Kerala in a grand function near the Power house which was presided over by Sri Vijayadas M.L.A.

The project area is in the Karimba Grama Panchayat, about 30 km north-east of Palakkad along the Palakkad-Mannarkkad route. The catchment of the waterfall is located between 76°35′ and 76°38′ East longitude and 10°53′ and 10°56′ North latitude (Figure 4.1). The Thuppanad Puzha in which the falls are situated is a tributary of Thuthapuzha draining into Bharathapuzha. Thuppanad Puzha originates from Palla Mala, in the Palakkad hills of Western Ghats, located south-west of Elival Muthikulam hills and south of Attappady plateau. The river flows westward for a length of 29 km before joining the Karimpuzha, north of Easwaramangalam. Here the river is called Thoothapuzha. The Meenvallom Falls as such is located 4.5 km downstream from its origin in the Karimba Panchayat, at around 10 km east of Kalladikkode in the Palakkad-Kozhikode national highway.

Technical details

  •  Turbine

Type : Horizontal axis Twin jet Pelton

  •  Generator

KVA rating : 1765

Number of poles : 10

Speed rpm : 600

  •  Penstock

Factory made spiral weld (SW) pipes

  •  Governor

As the system is to be synchronized with the grid and Synchronous Generator is proposed to be used, electronic-hydraulic governor suitable for isolated and parallel operation with the grid is envisaged in the system. The electronic – hydraulic governor consists of the following.

  •  Electronic controller.

This is designed as a standard rack PLC with interchangeable modules for the servo loop, water level control, operating module with the possibility of remote control, and power supply unit with an input voltage of 24 V or 110 V DC, and 230 V AC.

  •  Hydraulic power pack

Hydraulic power pack with two AC motor pump’s main and  standby,hand pump, pressure accumulator with maximum and minimum pressure switches and pressure gauge, oil tank with level gauge and drainage system, control valve and shut down solenoid valve.

  •  Generator

Type : Synchronous, Salient pole with Screen protected enclosure

Excitation : Brushless excitation system, shunt with current transformers

AVRs : Internal voltage regulation ±2.5 with under/over voltage protection, Under/over voltage frequency protection.

Instrumentation was carried out to measure the following hydrologic and meteorological

parameters:

Rainfall

Stream flow

Evaporation

Temperature

Humidity

In addition, periodic data collection was carried out to determine interception in the forest areas of the catchment, peak flow and moisture status in the catchment area. Preliminary geological investigations of the project sites were first undertaken during the field season 1994-95 by Dr. John Mathai, Scientist, Centre for Earth Science Studies (CESS), Thiruvananthapuram.

Investigations covered the following:

1. Weir site

2. Penstock alignment

3. Power house site

Environmental impact analysis of the project was carried out by the Centre for Earth Science Studies, Thiruvananthapuram