Lower Manair Dam

Location

The Lower Manair Dam is located on the Manair River at 18°24' N latitude and 79° 20' E longitude in Karimnagar District at Km.146 of Kakatiya Canal. The Manair River is a tributary of the Godavari River and the dam is built across the river at the confluence with Mohedamada River. The dam drains a catchment area of 6,464 square kilometres (2,496 sq mi) which includes 1,797.46 square kilometres (694.00 sq mi) of free catchment and the balance is intercepted catchment. Karimanagar town is 6 kilometres (3.7 mi) away from the dam.

In the vicinity of the LMD which is the only place of recreation for the people of Karimnagar, in the light of recent drowning incidents and the insecurity created by hooligans, security measures have been stepped up.

Features

Lower Manair Dam's construction was started in 1974 and commissioned in 1985. It is an Earth cum Masonry dam. The dam height above the deepest foundation is 41 metres (135 ft); the maximum height of the earth dam is 88 feet (27 m). The dam length is 10,471 metres (34,354 ft), top width is 24 feet (7.3 m). It has a volume content of 5.41 million cum with a reservoir water spread area of 81 square kilometres (31 sq mi) at FRL of 920.00 ft. The gross storage capacity of the reservoir is 680 million cubic meter and the live storage capacity is 380.977 million cum. The spillway is designed for discharge of capacity 14,170 cubic metres (500,000 cu ft)/ second (and is controlled by 20 gates of 15.24 by 7.31 metres (50.0 ft × 24.0 ft) size, while the maximum observed flood discharge is reported to be 9,910 cubic metres (350,000 cu ft)/second.

The storage behind the dam serves as a balancing reservoir for the Kakatiya Canal and regulates flow for irrigation. The command area for irrigation is 163,000 hectares (400,000 acres). The storage of the dam is also utilized as drinking water source for Karimnagar and Warangal towns and for reservoir fisheries (Pisciculture}.

The water quality status of the Lower Manair Reservoir was studied from September 2009 to August 2010 for the physico- chemical parameters such as water temperature, pH, turbidity, transparency, total dissolved solids, total hardness, chlorides, phosphate, nitrates, dissolved oxygen (DO) and biological oxygen demand (BOD). The results indicated that all parameters of water quality were within permissible limits and it was concluded that the water in the reservoir was fit for use for irrigation, drinking water supply and pisciculture.

Plankton studies

Based on plankton studies of the reservoir from September 2010 to August 2011, the rich biodiversity of the zooplankton is an indication that the storage water is unpolluted and suitable for uses such as irrigation, fisheries and drinking water supply. The field studies of the reservoir identified 34 species of zooplankton of which 16 are rotifera, 8 of cladocera, 6 of copepoda, 2 species of ostrocoda and 2 protozoa.

Aquatic plant studies

Investigations were carried out during 2013–2014 on the aquatic macrophyte diversity in the reservoir. The studies have reported macrophytes of "04 classes, 20 orders and 26 families, including five free floating macrophytes, ten submerged, and thirty three emergent species of weeds." Eichhornia crassipes species has been recorded all through the year. The submerged species of Vallisneria spiralis, Ceratophyllum demursum, Hydrilla verticillata, and also the rooted floating species of Ipomoea aquatica are reported throughout the year.

Reservoir fisheries

Studies were conducted in the LMD reservoir from June, 2013 to May, 2014 to identify the larvivorous activity of fishes. On the basis of morphometric and meristematic characters, the 58 fish species are identified in the reservoir. Also reported were 53 ornamental fish species comprising eight orders; of these 23 species belong to cypriniformes order. Awaous grammepomus, also called Scribbled goby was also identified.