There is a popular belief that Kayamkulam kayal was once lush green fields and Kayamkulam Raja, angry and desolate from being defeated by Travancore King Marthanda Varma, ordered his naval officers, Arattupuzha Arayars, to rupture the barrier separating it from the sea and let salt water in to make the fields un-cultivable.

[12] The Kayal area has wet and maritime tropical climate influenced by the seasonal heavy rains.

[13] The water was studied by Central Inland Fisheries Research Institute after NTPC was set up.

Biochemical oxygen demand (BOD5) values, Chemical oxygen demand(COD) values and nutrient content were high, these were attributed to NTPC effluent discharge and retting of coconut husks.

[6] The deeper part of the lake is poor in vegetation except for encrustation by blue green algae Oscillatoria.

[12] Environment Impact Assessment before setting up Rajiv Gandhi CCP in Kayamkulam noted that concentration of mercury and nickel in the sediments is much lower than the crust rocks.

Concentration of lead is marginally high but they are generally associated with chelates and other organic matter and are fixed in the sediment matrix and are not leachable.

Sediment is high in iron content possiblily because weathering of charnockite and pagmetite rocks.

She reports that most species of grey millets migrate to the lake during the months when Kayal is connected to the sea.

[14] An environment impact assessment by National Thermal Power Corporation in association with the Fisheries department lists about 70 species of fishes in the Kayal.

Besides the commercially important species there are about 30 other species of fish including northern whiting, bigeye trevally, black-tailed trevally, congaturi halfbeak, long-billed halfbeak, Quoy's garfish, chacunda gizzard shad, milkspotted puffer, diodon, Indian halibut, chorinemus, dusky sleeper, tank goby, mangrove red snapper, dory snapper, sleepy goby, sharptail goby, spotfin snouted goby Indian short-finned eel, Macrognathus guentheri, long whiskers catfish, yellow catfish, striped dwarf catfish, scarlet-banded barb, greenstripe barb, climbing perch, Indian carplet and spotted snakehead.

[17] The Kayal is also home to crab species Scylla serrata and Portunus pelagicus.

[14] The environment impact assessment survey conducted by NTPC, reports the presence of 27 species of birds that fall into 25 different genera.

These birds include common myna, common kingfisher, Malabar pied hornbill, snakebird, cattle egret, little ringed plover, Indian roller, house crow, jungle crow, jungle fowl, fork-tailed drongo, black-rumped flameback, little egret, Asian koel, common moorhen, black-capped kingfisher, house sparrow, black kite, white-throated kingfisher, yellow-throated sparrow, stork-billed kingfisher, baya weaver, red-vented bulbul, greater painted-snipe, black-headed ibis, common babbler and hoopoe.

[17] Environment Impact Assessment Survey conducted by NTPC, recorded the presence Amphipoda, Bivalvia, Gastropoda, Gastrotricha, Isopoda, Nemertea(ribbon worm), Oligochaeta, Polychaetes, Sipuncula(peanut worm) and Tanaidacea in the lake bed.

Tourism project that aims to exploit the tourism potential of Kayamkulam and nearby area aims build waterway connecting Kayamkulam Lake and National Waterway, Water sports complex, Seasting Gallery, Tsunami Memorial, Museum, Cycling Track, floating restaurant, Recreation Zone, Adventure zone and House boat terminal with Amenities like Tourist arrival centre, Tourist inter protection centre, Boardwalk and view point, Landscaping, Yard lighting, Houseboat Jetty and waterway for boats.

The majority of the plant site is reclaimed land from the Kayal which originally belonged to the Keral State Agricultural Department and was used for Grass Farming.

Total length of waterway in the Kayal is approximately 25 kilometres (16 mi) and Least Available Depth is at least 1.5 metres (4 ft 11 in).