CLASSIFICATIONS OF DAMS BASED ON STRUCTURE AND DESIGN

GRAVITY DAM

EARTH DAM

ROCKFILL DAM

ARCH DAM

BUTTRESS DAM (3 TYPES)

Deck type

Multiple archs

Massive head

STEEL DAM - 2 TYPES

TIMBER DAM

TYPES OF DAMS BASED ON USE

STORAGE DAMS |

DIVERSION DAMS |

DETENTION DAMS |

DEBRIS DAMS |

COFFER DAMS |

FACT CHECK

DANGERS

ACCIDENTS

Sept 20, 2017

Heavy rains recently Forced Kerala , Karnataka , and Tamil Nadu to open floodgates, causing large-scale dam age. TOI gives a lowdown on the different types of dams there are and the dangers they could pose...Designed to hold large volumes of water, these dams are made in wide valleys from concrete or stone masonry. Eg: Nagarjuna Sagar dam, TelanganaBuilt by compacting layers of soil with impervious material for the core and permeable substances on the up and the downstream sides.It resists forces mainly due to strength of soilBuilt with rock fragments and large boulders. A cement concrete or asphaltic concrete, which acts as an impervious membrane, is placed on the rockfill on the upstream to reduce seepage through the damCurved with convexity towards the upstream side, arch dam transfers water pressure mainly to abutments by arch action. Fit for narrow canyons. Eg: Idukki dam , Kerala| It has a sloping deck supported by buttresses| No deck slab. Horizontal arches are supported by buttresses| Here buttresses are flared to form massive headsDirect-strutted and cantilever steel damsMade from timber, this dam usually has sluicesMeant to store water during rain. Stored water is used for power generation, irrigation or for flood control projectsThese dams are constructed to divert water from a river to a canal or from a stream into a storage reservoirThese dams are constructed for flood controlThis dam retains debris like gravel, sand, and driftwood flowing in the riverto make water clearA temporary dam constructed to prevent water from entering aconstruction siteThere are 5,254 completed large dams and 447 under construction dams in India116 dams are located in Tamil NaduTamil Nadu’s Mettur and Sholaiyar - are masonry dams. The rest are earth damsInspection of dams involves checking the upkeep of hydromechanical equipment like shutters, tunnels and greasing lifting arrangements, according to PWD officialsEarthquake and geological damage: When water seeps into fissures in rocks below, pressure can lead to stress strong enough to trigger an earthquakeDisplacement of people living close to a dam site during construction and deaths during floodsIt can alter the water table level, flow of river and transportation of sedimentsBlock fish migration. Change in physical properties of the reservoir can affect aquatic lifeDams can give away if designed without considering the forces exerted by water during spate in riverMukkombu regulator’s eight gates out of 45 were washed away by strong currents of Kollidam river in Tamil Nadu| The wall of a Rs 389.31 crore dam collapsed a day before inauguration and inundated nearby areas of a township in Bhagalpur, Bihar. The dam was built as part of the Gateshwar Panth Canal Project