The huge softly rippling reservoir in Arena is a marriage of manmade technology and nature’s geographical systems. The reservoir is sited in an area where natural faulting gives rise to steep elevations and low valleys that provide a water storage area of over 680 hectares (1,700 acres).
The site, located between the El Pillar and Los Bajos faults,was covered with a thick tropical forest which had been cleared before the area was flooded to create the reservoir.
Two dams were built at different locations on the major rivers that flowed through the area. One a small weir on the Tumpuna River and the other a major earthfill dam across the Arena River.
The Arena Dam is the largest ever built in Trinidad and Tobago. Reaching up to 40.85 metres (134 feet) at its highest crest elevation, it has been built to withstand earthquakes of up to 8.0 on the Richter Scale.
Located at the Arena Reservoir is the Tumpuna Pump Station from which the Water and Sewerage Authority, during the wet
season when the rivers are high, draws water from the river and diverts it to the reservoir for storage.
The reverse happens in the dry season when river levels run low. Water is pumped back into the Arena River where some of it is
withdrawn for processing at the Caroni Water Treatment Plant. Putting the water back into the river also helps to maintain the
ecology of the river and ultimately the Caroni Swamp, into which the water flows.
Though the reservoir was a feat of man’s engineering ability, unlike many other symbols of progress, it has not destroyed the beauty of the natural environment.
Hawks, Black Bellied Ducks, Caimans and Pied Water Tyrants all have their habitats around the periphery of the reservoir. The vegetation is dotted with highly colourful flowering and fruit trees such as the Chaconia (the national flower) and the balata among others.
The virgin forest has been lost and the landscape drastically transformed but the site has acquired a new beauty with recreational benefits for all visitors. Though the area is not recommended for bathing, there are play parks for children, picnic tables and shady huts with areas for cooking. These provide a welcome escape from the hustle and bustle of every day life.