Periyar, , (meaning: ''big river'') is the longest river and the river with the largest discharge potential in the
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
n state of
Kerala
Kerala ( ; ) is a state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile regions of Cochin, Malabar, South ...
.
It is one of the few
perennial
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
rivers in the region and provides drinking water for several major towns.
The Periyar is of utmost significance to the
economy of Kerala
The economy of Kerala is the 9th largest in India, with an annual gross state product (GSP) of in 2020–2021. Per-capita GSP of Kerala during the same period is , the sixth largest in India. In 2019–20, the tertiary sector contributed arou ...
. It generates a significant proportion of Kerala's electrical power via the
Idukki Dam
The Idukki Dam is a double curvature arch dam constructed across the Periyar River in a narrow gorge between two granite hills locally known as '' Kuravan'' and ''Kurathi'' in Idukki, Kerala, India. At , it is one of the highest arch dams in As ...
and flows along a region of industrial and commercial activity. The river also provides water for irrigation and domestic use throughout its course besides supporting a rich fishery.
Due to these reasons, the river has been named the "Lifeline of Kerala".
Kochi
Kochi (), also known as Cochin ( ) ( the official name until 1996) is a major port city on the Malabar Coast of India bordering the Laccadive Sea, which is a part of the Arabian Sea. It is part of the district of Ernakulam in the state of K ...
city, in the vicinity of the river mouth draws its water supply from
Aluva
Aluva (; also known by its former name Alwaye) is a town in the Ernakulam District in Kerala, India. It is a part of the Kochi metropolitan area and is situated around from the city center on the banks of Periyar River. A major transpor ...
, an upstream site sufficiently free of seawater intrusion. Twenty five percent of Kerala's industries are along the banks of river Periyar. These are mostly crowded within a stretch of in the
Eloor
Eloor is a suburb of Kochi and a municipality in Paravur Taluk, Ernakulam District in the Indian state of Kerala, India. It is an industrial area situated around north of the city centre. It is an island of 14.21 km2 formed between two dis ...
-Edayar region (Udhyogamandal), about north of Kochi harbor.
Origin and path
![Periyarriver-bh](https://upload.wikimedia.org/wikipedia/commons/f/f9/Periyarriver-bh.jpg)
The Periyar has a total length of approximately and a catchment area of , of which is in Kerala and is in Tamil Nadu.
Sources
The source of the Periyar lies high in the
Western Ghats.
The state of Kerala asserted during the hearings on the Mullaperiyar issue in the
Supreme Court of India
The Supreme Court of India ( IAST: ) is the supreme judicial authority of India and is the highest court of the Republic of India under the constitution. It is the most senior constitutional court, has the final decision in all legal matters ...
that the Periyar originates in Kerala, flows entirely through Kerala and joins the sea in the Kerala.
This was also admitted by the state of Tamil Nadu in the court.
Periyar originates at the southeastern border of
Idukki district.
The source of the river lies in the remote forests of the
Periyar Tiger Reserve
Periyar National Park and Wildlife Sanctuary (PNP) is a protected area located in the districts of Idukki and Pathanamthitta in Kerala, India. It is notable as an elephant reserve and a tiger reserve. The protected area encompasses , of whi ...
.
The river originates from Chokkampatti Mala,
a peak on the southern boundary of the Periyar Tiger Reserve.
Course
In its early course, the river flows in a narrow north sloping valley starting from the Chokkampatti hills and extending north about , with a number of sharp lateral ridges running down to it from east and west.
After flowing from its origin and on reaching Mount Plateau at its eastern end, it is joined by the west-flowing Mullayar—an important tributary—at Mullakudy.
During this journey the Periyar traverses through the Periyar Tiger Reserve, flowing across or forming the boundaries between various sections of the reserve. Going downstream, it defines a part of the border between Periyar section
of the reserve in the east and Sundaramala section
in the west and then the borders between Moolavaigai
and Thannikudy
sections in the east and Ummikuppan,
Mlappara
and Aruvioda
sections in the west before reaching the Periyar Lake.
The
Mullaperiyar dam
Mullaperiyar Dam , is a masonry gravity dam on the Periyar River in the Indian state of Kerala It is located above the sea level, on the Cardamom Hills of the Western Ghats in Thekkady, Idukki District of Kerala, India. It was constructed bet ...
is constructed at the confluence of the Periyar and Mullayar to create the Periyar Thekkady lake and reservoir, as well as the
Periyar National Park
Periyar National Park and Wildlife Sanctuary (PNP) is a protected area located in the districts of Idukki and Pathanamthitta in Kerala, India. It is notable as an elephant reserve and a tiger reserve. The protected area encompasses , of which ...
. The area belonging to Tamil Nadu in the Periyar basin is located far down the river from the Mullaperiyar Dam site.
This area is drained by the tributary Nirar, which is diverted to Tamil Nadu as a part of inter-state Parambikulam-Aliyar Project (PAP) agreement.
From Periyar Thekkady lake and reservoir, some water is diverted eastwards to Tamil Nadu via a tunnel. The diverted water, after power generation, is let into the Suruliar river (a tributary of the
Vaigai River
The Vaigai is a river in the Tamil Nadu state of southern India; it passes through the towns of Theni, Dindigul and Madurai. It originates in Varusanadu Hills, the Periyar Plateau of the Western Ghats range, and flows northeast through the K ...
) thereby resulting in an inter-basin transfer of water.
Downstream of the Mullaperiyar dam, the Periyar continues to flow northwestward for , exiting the Periyar Tiger Reserve and passing through
Vandiperiyar
Vandiperiyar, , is a spice village in Idukki district, Kerala, India. It is known for tourism, tea and coffee plantations, black pepper and other spice products. A number of tea factories are situated in the town. The Periyar River flows throug ...
,
Elappara
Elappara is a village in Idukki district in the Indian state of Kerala. It is one of the panchayaths in Peerumedu taluk. The area is marked by a cool climate as the region is situated at an elevation of more than above the sea level. Elappara ...
and
Ayyappancoil
Ayyappancoil, also spelt Ayyappankovil is a village in newly formed Idukki taluk in Idukki district in the Indian state of Kerala. It is highly noted for the newly constructed suspension bridge with a length of 200 meters and the old historic S ...
to the Idukki reservoir formed by the Idukki, Cheruthoni and Kulamavu dams. The Idukki dam is constructed across the Periyar river on the famous Idukki gorge formed by the Kuravan and Kurathi hills.
The main Periyar below the Idukki reservoir flows due north parallel to the western edge of the Idukki plateau and is joined by the Perinjakutty from the east and Muthirapuzha from the north.
After the confluence with Muthirapuzha, the river flows northwestwards and enters Ernakulam district at
Neriamangalam
Neriamangalam is a village in Ernakulam district in the Indian state of Kerala.
Neriamangalam is on the banks of Periyar River. It is on the border of Ernakulam and Idukki districts. Agriculture is the predominant occupation in this area. The ...
. It is joined by its major tributary, the Idamalayar, upstream of the
Bhoothathankettu
Bhoothathankettu is a dam and tourist spot in Ernakulam district in Kerala, India. It is situated outside the village of Pindimana, about 10 km away from the town of Kothamangalam and 50 km away from the main city of Kochi.
The ...
barrage.
After receiving the waters of the Idamalayar river, the Periyar flows west along the midlands of Ernakulam district.
At Aluva, the river bifurcates into the Marthandavarma and the Mangalapuzha branches. The Mangalapuzha branch joins
Chalakudy River
Chalakudy River or Chalakudy Puzha is the fifth longest river in Kerala, India. The river flows through Thrissur district, Palakkad district and Ernakulam district of Kerala. The total drainage area of the river is 1704 km2. Out of this,1 ...
and empties into the
Lakshadweep Sea at
Munambam
Munambam is a suburb of Kochi, India at the north end of Vypeen Island, surrounded by the Arabian Sea on the west, Periyar river on the east, and a mouth of the sea on the north. The main occupation of its inhabitants is fishing.
Munambam is ...
, and the Marthandavarma branch flows southwards, again dividing into two near Kunjunnikkara island, going through the Udhyogamandal area and finally draining into the Cochin backwater system (part of
Vembanad
Vembanad is the longest lake in India, as well as the largest lake in the state of Kerala. The lake has an area of 230 square kilometers and a maximum length of 96.5 km. Spanning several districts in the state of Kerala, it is known as Ve ...
Lake) at
Varappuzha
Varappuzha, , (also known by its former name Verapoly) is a northern suburb of the city of Kochi. It is a census town in Paravur Taluk, Ernakulam district in the Indian state of Kerala. Situated around 15 km (9 mi) from the city centre ...
. The Vembanad backwaters are connected to the Lakshadweep Sea at Cochin and
Kodungallur
Kodungallur (; also Cranganore, Portuguese: Cranganor; formerly known as Mahodayapuram, Shingly, Vanchi, Muchiri, Muyirikkode, and Muziris) is a historically significant town situated on the banks of river Periyar on the Malabar Coast in Thr ...
.
Tributaries
Its major
tributaries
A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage b ...
are:
*
Muthirapuzha River
Muthirapuzha River is one of the major tributaries of the Periyar River, the longest river in Kerala state south India. It begins in remote forests above the Pooyamkutty- Edamalayar valley in Ernakulam district of Kerala, and joins the Periyar ...
*
Mullayar River
*
Cheruthoni River
*
Perinjankutti River
Perinjankutti River is one of the major tributaries of the Periyar River, the longest river in Kerala state of south India.
See also
* Periyar River - Main river
Other major tributaries of Periyar river
*Muthirapuzha River
*Mullayar
*Cheruth ...
*
Edamala River
Minor tributaries are:
Muthayar, Perunthuraiar, Chinnar, Cheruthony, Kattappanayar
Although the Chalakudy river in strict geological sense is a tributary of the Periyar, for all practical purposes it is treated as a separate river by Government and other agencies. Chalakudy river itself has a catchment area of , with in Kerala and in Tamil Nadu.
Basin
![Anamudi from Munnar Gundumalai road](https://upload.wikimedia.org/wikipedia/commons/7/72/Anamudi_from_Munnar_Gundumalai_road.jpg)
The Periyar basin spreads over an area of , most of it in central Kerala. It lies between latitudes 9°15’30"N and 10°21’00"N and longitudes 76°08’38"E and 77°24’32"E. The river drains parts of
Idukki,
Ernakulam
Ernakulam () is the Central Business District of the city of Kochi in Kerala, India and has lent its name to the Ernakulam district. Many major establishments, including the Kerala High Court, the office of the Kochi Municipal Corporation a ...
and
Thrissur
Thrissur (), formerly Trichur, also known by its historical name Thrissivaperur, is a city and the headquarters of the Thrissur district in Kerala, India. It is the third largest urban agglomeration in Kerala after Kochi and Kozhikode, and t ...
districts in Kerala
and
Coimbatore district
Coimbatore district is one of the 38 districts in the state of Tamil Nadu in India. Coimbatore is the administrative headquarters of the district. It is one of the most industrialized districts and a major textile, industrial, commercial, educ ...
in Tamil Nadu.
The basin has an inverted "L" shape with a maximum width at the intersection. The length-width ratio is 6:1. Most of the streams flow in deep gorges with steep valleys along the highlands of the basin.
Coming out of the hills, the Periyar flows west and its basin occupies the northern part of Ernakulam district, covering the region from Neriamangalam through Aluva
to Varapuzha and Munambam.
The Periyar is an
8th order stream with considerable development of tributary network. The average drainage density of the basin is 2.46 km/ km
2 with a total number of first order streams of 15,773. The total stream length inclusive of all orders in the basin is . The river originates from the high hills of the Western Ghats and the influence of tectonism can be evidenced from the stream pattern and presence of structural valleys. Forests occupy nearly (28%) of the basin area whereas cardamom and settlement with mixed tree crops occupy an area of and respectively. The basin is ecologically sensitive. Nearly 80% of the total area situated in the high ranges are susceptible to erosion and mass movements.
Anamudi
Anamudi is a mountain located in Ernakulam district and Idukki district of the Indian state of Kerala. It is the highest peak in the Western Ghats and in South India, at an elevation of and a topographic prominence of . The name Anamudi lite ...
, at the highest peak in South India, is the highest point in the basin.
Cardamom Hills
![Cardamom Hills](https://upload.wikimedia.org/wikipedia/commons/8/8e/Cardamom_Hills.jpg)
The upper part of the Periyar basin extends across the
Cardamom Hills
The Cardamom Hills or Yela Mala are mountain range of southern India and part of the southern Western Ghats located in Idukki district, Kerala, India. Their name comes from the cardamom spice grown in much of the hills' cool elevation, wh ...
. In the north, these hills extend up to the high
Munnar
Munnar () is a town and hill station in the Idukki district of the southwestern Indian state of Kerala. Munnar is situated at around above mean sea level, in the Western Ghats mountain range. Munnar is also called the "Kashmir of South Indi ...
saddle running east to Chokkanad Mala and further on to Kolukkumala on the eastern edge of the Ghats. In the south, the hills reach up to the westerly spur at Chokkampatti Mala.
This section of the basin is divided into three parts.
Source - Southern Cardamom Hills
The southernmost part of the Cardamom Hills i.e. the source of Periyar River is a narrow valley extending south of
Kumily. This is the southern extreme of the Periyar basin. It is less than wide and is about long.
The upper catchments of Periyar extend as a wedge deep into the northeastern corner of the neighboring Pandalam Hills. This section of the Cardamom Hills extends deep into but is clearly separated from the Pandalam Hills. The main Western Ghats watershed line forming the eastern border of the Cardamom Hills is highest to the southeast of the Kumily Gap. Here the High Wavies branch off towards north-west into Tamil Nadu, with some peaks reaching elevations of over along the border between Kerala and Tamil Nadu. Further south, the ridge along the watershed line is heavily forested. This part of the Cardamom Hills is called the Sivagiri Range and it extends south up to Chokkampatti Mala which is at the junction of
Pamba and Periyar River basins. The southern boundary of the Cardamom Hills runs along a westerly spur hill starting from the Chokkampatti Mala which initially runs north and then turns northwest almost parallel to the Sivagiri Range. This ridge separates the basin of Pamba from Periyar. From its source near Chokkampatti Mala initially Periyar flows north between these two heavily forested ridges. The valley floor is at an elevation of and the ridges on either side often reach . This valley of Periyar at its source and the valley of Kunthi River in the Silent Valley are the only two forested higher valleys in the Western Ghats left intact even now. The Periyar Tiger Reserve is mostly within this southernmost part of the Cardamom Hills.
Cardamom Hills plateau
A poorly defined ridge that runs from near Chakkupallam (north of Kumily) on the border between Kerala and Tamil Nadu extending southwest to near Vallakkadavu segregates the upper reaches of Periyar from the rest of the Cardamom Hills. Immediately downstream of Mullaperiyar dam, Periyar cuts through this ridge. North of this ridge, the Cardamom Hills extend up to the high Munnar saddle.
Here, east of the river channel, the undulating plateau rises up to the watershed line of the Western Ghats. This section drains into the Periyar through the Perinjankutty Ar and the drainage channel is essentially from south-east to north-west.
This portion of the Cardamom Hills is on an average high. The northern edge of the Cardamom Hills bordering the High Range Plateau on the other hand slopes steeply to the south and is drained by Panniyar. The Panniyar joins the Muthirapuzha, which drains the High Range Plateau section of the Periyar Basin in the north. The crestline of the Cardamom Hills in this section along the border with
Theni
Theni is a valley town situated in the Indian state of Tamil Nadu at the foothills of Western Ghats. It is the headquarters of the Theni district, located in a distance of 70km from Madurai. It is known for the large-scale trading of garlic, c ...
and
Kambam
Cumbum or Kambam (), is a town and municipality in Theni district (in the western part of the Madurai Region), an Indian state of Tamil Nadu.
Geography and Climate
Cumbum is located at . It has an average elevation of 391meters (1282 feet). O ...
, in comparison with the rest of the main watershed line of the Cardamom Hills and the High Ranges, is low, reaching up to only about . East of Chakkupallom, a small part of the adjacent Vaigai basin protrudes from Tamil Nadu into Kerala in this section. This portion of the Periyar basin is drier than all other west sloping parts of the Western Ghats. It has no significant extent of natural forests remaining anywhere. At the turn of the 20th century, it was fully covered by evergreen forests.
Idukki Sub-plateau
The portion west of the main Periyar channel which flows from south to north here, is the true Idukki sub-plateau. This is the lowest part of the Cardamom Hills sloping towards the north in which the Idukki reservoir is located.
It is separated from the rest of the Cardamom Hills by the deep channel of the Periyar River. The sub-plateau extends north from near Ayyappankoil to near Neriamangalam. Its western border is the clearly demarcated scarp face of the Ghats descending to the plains of
Thodupuzha
Thodupuzha (തൊടുപുഴ) is a municipal town located in Idukki district, Kerala, India, that covers an area of . It lies on the banks of Thodupuzha river, which merges with the Kaliyar and Kothamangalam rivers at Muvattupuzha to for ...
. This high western crestline separates the Periyar catchment from the
Manimala
Manimala is a small town and a village in Kottayam district in the Indian state of Kerala, situated about from the nearest town Kanjirappally. It's declared as a folklore village since 2011 by the central government to promote folklore.
Ge ...
,
Meenachil
Meenachil is the north-eastern region of Kottayam district in Kerala, south India. The name originates from Meenakshi, the Hindu Goddess. Pala is the main city in Meenachil. The arterial river of the district is also named Meenachil.
Geogra ...
and Moovattupuzha drainage basins. It ends in the north along the channel of Periyar from Neriamangalam to Panamkutty. The catchment of Kattappana Ar located beyond the southeastern corner of the Idukki reservoir also falls in this portion. A southwest to northeast ridge called the Chekuthan Mala separates the Idukki Sub-plateau from the Peermade Plateau as well as the main mass of Cardamom Hills. Its eastern boundary is a northwest to southeast ridge separating the Idukki reservoir from the Kallar/Perinjankutty tributary of Periyar which drains the main Cardamom Hills. The Idukki Subplateau is at an average elevation of . This area was heavily forested till the 1950s but now only three small fragments of forest vegetation alone remain. The largest is within the Idukki Wildlife Sanctuary.
South of
Vagamon
Vagamon ( ml, വാഗമൺ) is an Indian hill station and a revenue village primarily located in Peerumedu taluk of Idukki district (majority area including Vagamon town), and also Meenachil taluk and Kanjirappally taluk of Kottayam ...
, the tributaries of Meenachil, Manimala and Pamba have eroded away extensive areas of the Periyar basin between Ayyappankovil and Vallakkadavu. The Periyar only has a narrow strip of the Cardamom Hill tableland to flow northward here.
High Range Plateau
The High Range Plateau is located around Munnar and
Devikulam
Devikulam () is a Grama Panchayat and small hill station of about from Munnar in the Idukki District of Kerala State, India. It lies above sea level.
Etymology
The name Devikulam is a conjunction of the words ''Devi'', from the goddess Devi a ...
. It has an average elevation of about and drains to the south through Muthirapuzha into Periyar. The high
Rajamala
Rajamala is a hill station in Eravikulam National park located about 15 kilometers from Munnar, Kerala, India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, t ...
-Anamudi-Umayamala part of the main Anamalai ridge forms its northern boundary. A spur ridge starting from the main Anamalai ridge, going south immediately to the west of Munnar and continuing on to Parvathi Mala forms the western boundary of the High Range Plateau. This ridge separates the High Ranges from the Lower Periyar Valleys further to the west. The eastern edge of the High Range plateau runs north from Kolukkumala, at the junction of the High Range Plateau with the Cardamom Hills, and continues onto the Top Station along the border between Kerala and Tamil Nadu. The High Range portion is essentially the south and west draining slopes of the main Anamalai ridge with the Cardamom Hills located to its south. All the northern slopes of the main Anamalai ridge falling within Kerala drain into Idamalayar and Pooyamkutty Ar, both tributaries of Periyar.
The High Range Plateau has been almost totally transformed by tea plantations and hydroelectric dams. The original forest was mostly of the Shola-Grassland type. From the biodiversity value, this unit is of special importance because of its specialized high altitude flora and fauna.
Lower Periyar Valleys
The lower valleys of Idamalayar and Pooyamkutty Ar constitute the Lower Periyar Valleys. The exceedingly violent impact of very heavy rainfall on a likely geologically unstable part of the Western Ghats where there is extensive faulting has caused
accelerated weathering and erosion, carving out a complex of deep valleys on the western face of the High Range Plateau. This topographically complex segment of the Western Ghats extends from near Neriamangalam in the southwest to Panamkutty in the southeast along the Periyar River and continues north up to the watershed divide between the Periyar and the Chalakudy Basins. Its eastern border is the main Anamalai ridge. This section of western slope of the Western Ghats is deeply dissected and has geographical as well as ecological characteristics found nowhere in the Western Ghats. To the south of this section is the Idukki sub-plateau and to the southeast, the Cardamom Hills. The western edge of Panniyar and Muthirapuzha Basins form the eastern border of this section. The Parvathimudi-Umayamala ridge forms the northeastern corner of the Lower Periyar Valleys.
Towards north, the Lower Periyar Valleys and the Periyar Basin extend up to the Idamala gorge cut by Periyar’s northernmost tributary – Idamalayar. The basin is bounded in the north by the ridge separating Sholayar from the Idamala River. This ridge is a spur hill extending from near Valaparai in Tamil Nadu, projecting far west into Kerala.
The Idamala gorge separates the Sholayar forests in the Nelliyampathies towards the north from the southern Anamudi Reserved Forest and High Range Plateau.
The area belonging to Tamil Nadu in the Periyar basin is situated here. This area forms the north-eastern corner of the Periyar basin. It is drained by the tributary Nirar, which runs in a South Westerly Direction and falls into Idamalayar.
Within this section there are a series of deep west-sloping valleys where the valley floors are often at elevations less than . Separating these valleys are a jumble of steep hills and flat topped plateaux with scarp faces rearing up to elevations of around . The Idamala and Pooyamkutty rivers drain most of this section while its southern edge drains into the main Periyar. This tract is almost entirely forested and the forests extend northwest between Periyar and Chalakudy rivers along the plains almost up to Kalady.
Periyar Midlands and Lowlands
To the west of the Lower Periyar Valleys are the midlands, which are characterized by undulating topography with small hills separated by valleys. The general gradient is towards the west here. The lowlands occur as a narrow belt almost parallel to the present shoreline. The landforms of this section are broad valleys, submerged lands with swamps and marshes and subdued sand dunes. Many parts of the area are directly connected to the backwaters with a network of canals. The river bifurcates near Aluva into two major distributaries; one continues to flow through Desam as Mangalappuzha and finally drains into the Lakshadweep Sea. The Chalakudy river also joins to this branch of the Periyar south-east of Kodungalloor which expands to its maximum width at Munambam. The Marthandavarma branch flows southwards, again dividing into two near Kunjunnikkara Island, and finally drains into the Vembanad backwaters at Varapuzha.
The most industrialized zone of Periyar lies in this part of the basin between Angamaly and Cochin, with over 50 large and medium scale industries. The Edayar branch of Periyar caters to the needs of these industries.
Dams
Hydro-electric projects
![Idukki dam](https://upload.wikimedia.org/wikipedia/commons/e/ec/Idukki_dam.JPG)
The Idukki Dam is the largest hydro-electric project in Kerala and lies on the Periyar. It is the biggest dam of its kind (a concrete, double curvature parabolic, thin arc dam
) in Asia and the second-biggest in the world. Its generators have a power output of 780 MW (), and generate electricity through the underground facility at Moolamattam, built by an India-Canada joint venture. Power generation at Idukki is minimal during the
monsoon
A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscil ...
. The dam also permits storage of water for the dry summer period when many other reservoirs in the area are low. Since the commissioning of the Idukki project in 1976, tail-race water (between 19.83-78.5 m
3/s) has been diverted from the Idukki reservoir through the Moolamattom power station into the Thodupuzha tributary of the Muvattupuzha river.
There are other hydro-electric generation facilities on the river at Pallivasal, Chenkulam, Panniyar, Neriyamangalam and Lower Periyar.
Reservoirs
The important reservoirs in the Periyar basin within Kerala are Bhoothathankettu,
Idamalayar, Lower Periyar,
Mattupetty, Anayirangal, Kundala,
Ponmudi
Ponmudi (the Golden Peak) also known as Kashmir of Kerala is a hill station in the Peringamala gramapanchayath of Trivandrum District of Kerala in India. It is located 22km west of Vithura town, 53 km north-east of Trivandrum City, ...
, Kallarkutti, Idukki (formed by construction of three dams—
Idukki,
Cheruthoni
Cheruthoni () is a town on the banks of Cheruthoni River, a major tributary of the Periyar River, the second longest river in Kerala state, India. The area is known by Cheruthoni Dam, which is a part of Idukki reservoir, which provide hydroelec ...
and Kulamavu),
Sengulam, Kallar, Erattayar and Mullaperiyar.
The dams falling within Tamil Nadu in the Periyar basin are the Upper Nirar Weir and the Lower Nirar Dam. These dams help divert water from the Nirar tributary of Periyar to the adjacent Sholayar basin.
Irrigation
The Periyar valley Irrigation project in Ernakulam district envisages the utilization of the tail race discharge from the completed Hydel scheme in the Muthirapuzha tributary of river Periyar together with the controlled release from Ennackal dam constructed by
Kerala State Electricity Board
Kerala State Electricity Board (KSEB) is an Indian public sector undertaking under the Government of Kerala that generates, transmits and distributes electricity in the state under government monopoly. Established in 1957, the agency comes und ...
under Hydel scheme across the Idamalayar tributary and the dependable run off from the uncontrolled catchment of Periyar river, for irrigating an area of of land lying on the left bank of Periyar river through a network of canal system and controlling devices. The scheme consists of the Periyar Barrage at Bhoothathankettu with a catchment area of along with a network of canals.
Apart from irrigation on left bank of Periyar, the project also enables a supply of minimum quantity of water through the river to check the intrusion of salinity at lower reaches of the river as well as to meet the requirements of many lift irrigation schemes of river Periyar. Supply of water for drinking and industrial purposes are met by a portion of storage water by the barrage of Bhoothathankettu.
Inter-basin transfer of water
Mullaperiyar dam
Mullaperiyar Dam , is a masonry gravity dam on the Periyar River in the Indian state of Kerala It is located above the sea level, on the Cardamom Hills of the Western Ghats in Thekkady, Idukki District of Kerala, India. It was constructed bet ...
was one of the earliest instances of inter-basin transfers in the peninsular India. While it met the demand for water on one hand, it led to the deterioration of water quality downstream of the river. Salinity intrusion and pollution dispersion problems arose in the lower reaches of the Periyar due to non-availability of sufficient quantity of water for flushing. Another inter-basin transfer from the Periyar to the Muvattupuzha river due to the Idukki project has further adversely affected the downstream flow in the Periyar river.
The Parambikulam Aliyar Project (PAP) agreement was conceived to harness and share the waters in the inter-State rivers in
Bharathappuzha
Bharathappuzha ("River of Bhārata"), also known as the Nila or Ponnani River, is a river in India in the state of Kerala. With a length of 209 km, it is the second longest river that flows through Kerala after the Periyar. It flows throu ...
, Chalakkudypuzha and Periyar basins. Nirar and Anamalayar, tributaries of Periyar are covered under this agreement.
Water from these rivers are transferred to the adjacent Sholayar basin as part of the PAP agreement.
Due to all the diversions in its basin, the Periyar has lost 22 per cent of its average flow.
Ecological significance
![Thattekkad Bird](https://upload.wikimedia.org/wikipedia/commons/5/5f/Thattekkad_Bird.jpg)
South of the Mullaperiyar reservoir, at the source of Periyar River, there is an unbroken stretch of about of sheltered, unmodified rainforests within the Periyar Tiger Reserve. These rainforests extend further west into the adjacent Pamba basin within the Gudarakal Forest Range and continue south beyond the Gudarakal Range into the forests of the Achankovil Division. This entire stretch contains about of undisturbed wet evergreen forests typical of the
Western Ghats.
The forests on the upper reaches of Periyar are mostly inaccessible and is one of the least disturbed evergreen forests left in the Western Ghats.
The Periyar Tiger Reserve (PTR) is also one of the most ecologically diverse regions in India. The flora of the reserve is very rich and diverse. Out of the estimated 3,800 species of angiosperms of Kerala, 1,966 have been reported from within the reserve. Nowhere in the subcontinent, has such a large number of taxa been reported from an area comparable to that of the PTR. Apart from this, the reserve also contains an estimated 323 species of birds, 38 species of fish and 44 species of reptiles.
The Periyar plateau forms a part of the
Project Elephant Project Elephant was launched in 1992 by the Government of India Ministry of Environment and Forests to provide financial and technical support to wildlife management efforts by states for their free-ranging populations of wild Asian Elephants. The ...
Reserve 10, which also includes the
Agasthyamalai
Agastyaarkoodam is one of the peaks in the Western Ghats of Tirunelveli District of Tamil Nadu, India. This peak is a part of the Agasthyamala Biosphere Reserve which lies on the border between the Indian states of Tamil Nadu, Tirunelveli ...
-Mahendragiri hills. The landscape on the Periyar Plateau portion of Elephant Reserve 10 maintains the most intact elephant range in Southern India. This area is believed to harbour about 2,000 elephants and is one of the potential landscapes for the long-term conservation of the species. This population is genetically more diverse and distinct from the much larger elephant population further north in the Ghats. This region is also known for its rich biodiversity. On the other hand, the landscape has also witnessed a variety of developmental activities including commercial plantations, hydroelectric and irrigation projects and other forms of infrastructural development that impede the movement of elephants.
Thattekad Bird Sanctuary, one of the important bird sanctuaries of India, is an evergreen low-land forest located between the branches of Periyar River. It has a rich and varied birdlife. Several species of birds, both forest birds as well as the water birds visit the sanctuary.
Dr. Salim Ali, India's greatest ornithologist, once described this tiny, bird sanctuary, located about north-east of Kochi, as "The richest bird habitat in peninsular India".
Periyar is one of the six major rivers flowing into the Vembanad lake. Vembanad Kol Wetland was included in the list of wetlands of international importance, as defined by the Ramsar Convention for the conservation and sustainable use of wetlands.
It is home to more than 20,000 waterfowls—the third largest such population in India.
Religious and cultural significance
There are several places of religious significance along the banks of the Periyar. The famous
Aluva Sivarathri festival
Aluva Sivarathri Festival is the Sivarathri celebrated in Aluva Mahadeva Temple in Aluva, Kochi in the state of Kerala, India The celebration of Sivarathri in Aluva is very famous in Kerala. The month of Kumbham is noted for the Sivarathri fe ...
is celebrated on the banks of the Periyar River in Aluva.
The temple festival is conducted every year on Sivarathri day of the
Kumbham
The Malayalam Calendar is a sidereal solar calendar used in Kerala. The origin of the calendar has been dated to 825 CE, the beginning of the Kollam Era.
There are many theories regarding the origin of the era, but according to recent schola ...
month of Malayalam calendar. The Siva temple on the sand bank of Periyar River throngs with devotees every year on Mahasivarathri day.
Kalady
Kalady or Kaladi is a town located between Angamaly and Perumbavoor, east of the Periyar river, near to Malayattoor in Ernakulam district of Kerala, India, not far from Cochin International Airport. It is notable as the birthplace of 9th centu ...
is a town located on the banks of the Periyar river. It is the birthplace of Sri
Adi Shankara
Adi Shankara ("first Shankara," to distinguish him from other Shankaras)(8th cent. CE), also called Adi Shankaracharya ( sa, आदि शङ्कर, आदि शङ्कराचार्य, Ādi Śaṅkarācāryaḥ, lit=First Shanka ...
, the
Hindu
Hindus (; ) are people who religiously adhere to Hinduism.Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pages 35–37 Historically, the term has also been used as a geographical, cultural, and later religious identifier for ...
philosopher who consolidated the doctrine of
Advaita Vedanta
''Advaita Vedanta'' (; sa, अद्वैत वेदान्त, ) is a Hinduism, Hindu sādhanā, a path of spiritual discipline and experience, and the oldest extant tradition of the Āstika and nāstika, orthodox Hindu school Ved ...
. Kalady started featuring in the spiritual map of India only after its rediscovery in the late 19th century by the then Shankaracharya of
Sringeri
Sringeri (IAST: Śṛngēri) also called Shringeri is a hill town and Taluk headquarters located in Chikkamagaluru district in the Indian state of Karnataka. It is the site of the first maṭha ( Dakshinamnaya Sringeri Sharada Peetham) establi ...
and the subsequent consecration of a temple for Sri Adi Shankara in 1910.
Located from Kochi, the
Malayatoor
The St Thomas Syro Malabar Catholic International Shrine, Malayattoor (or Malayatoor Church) is one of the eight international shrines in the world, situated in Malayattoor Angamaly, Ernakulam district of Kerala, India.
The Malayatoor Church att ...
Church is situated atop the high Malayatoor Hill. The church is dedicated to
St. Thomas, who is believed to have prayed at this shrine. One of the most important Christian pilgrim centres in Kerala, this holy shrine attracts devotees in very large numbers not only from Kerala but also from the neighbouring states. This famous church is situated at Kurisumudi,
a verdant hill in the Western Ghats girdled partially by the Periyar (river). The Church has a life-size statue of St. Thomas and the imprint of the feet of the Apostle on a rock. This shrine has now been accorded an international pilgrimage station.
Environmental issues
Pollution
The lower reaches of the Periyar are heavily polluted. Industries in the Eloor industrial zone discharge waste into the river. Greenpeace India describes the lower Periyar as "a cesspool of toxins, which have alarming levels of deadly poisons like
DDT
Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. ...
,
endosulfan,
hexa
Numeral or number prefixes are prefixes derived from numerals or occasionally other numbers. In English and many other languages, they are used to coin numerous series of words. For example:
* unicycle, bicycle, tricycle (1-cycle, 2-cycle, 3-cy ...
and
trivalent chromium,
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
,
cyanide
Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms.
In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...
,
BHC". Several studies have pointed out that the riverbed has deposits of heavy metals like lead, cadmium, mercury, chromium, nickel, cobalt and zinc and the ecosystem of the river has many dead zones. Some of the major recommendations are ensuring zero effluent discharge from the industrial units in the Eloor-Edayar stretch and zero emission from companies. Pollution of the river and surrounding wetlands has almost wiped out traditional occupations, including fishing and farming.
Illegal sand mining
Illegal sand mining
Sand theft or unauthorised or illegal sand mining leads to a widely unknown global example of natural and non-renewable resource depletion problem comparable in extent to global water scarcity. Beach theft is illegal removal of large quantities ...
from the Periyar is another major environmental issue. Studies have pointed out that the quantity of sand being mined from the Periyar is at least 30 times the actual quantity that can be taken out without causing damage to the river’s environmental system.
In the Periyar river basin, land sand mining is widespread in the plateau region in the highlands. Mining of sands from these areas impose severe environmental problems to the river basin environment.
Environmental protection efforts
Efforts have been made to prevent soil erosion on the banks of river periyar at
Aluva Sivarathri manappuram (sand bank) through afforestation programs headed by renowned environmentalist,
Prof. S. Sitaraman, since 1992. The Aluva Environmental Protection Forum
started by Sitaraman and others have played a pivotal role in the prevention of illegal sand mining and water pollution in the lower reaches of the river.
Dispute
The control and safety of the Mullaperiyar dam on the river and the validity and fairness of the corresponding lease agreement have been points of dispute between Kerala and Tamil Nadu states. Intertwined with this, there is a dispute as to whether the Periyar should be classified as an inter-state river or not. Kerala states that the Periyar is an intrastate river since no part of it flows through Tamil Nadu. The river originates in Kerala, flows entirely through Kerala and joins the Arabian Sea in the Kerala. Although these facts have been admitted by Tamil Nadu,
it counters that the Periyar should be considered an inter-state river since a part of the catchment of the river lies in Tamil Nadu.
It has also cited a 1950 report signed by the then Kerala state irrigation minister V R Krishna Iyer recording that Periyar is an inter-state river since some of its drainage area lay in
Madras state
Madras State was a state of India during the mid-20th century. At the time of its formation in 1950, it included the whole of present-day Tamil Nadu (except Kanyakumari district), Coastal Andhra, Rayalaseema, the Malabar region of North and c ...
.
Essentially, the dispute over the status of the river comes down to the definition of an inter-state river, with Kerala supporting the definition to be according to the course of the river,
while Tamil Nadu favouring the definition to be according to the catchment area of the river.
The Supreme Court of India, in its verdict on 7 May 2014, stated that although the Periyar rises in and traverses only in the territory of Kerala before entering into Arabian sea, no part of the land in Tamil Nadu abuts river Periyar and that Tamil Nadu is not a riparian state of the Periyar river, the fact that a small part of the Periyar river basin lies in Tamil Nadu is enough to make the river interstate in nature.
See also
*
2018 Kerala floods
Notes
References
External links
{{Hydrography of Tamil Nadu
Rivers of Kerala
Bodies of water of the Arabian Sea
Rivers of the Western Ghats
Rivers of India