Cotter River

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Cotter River
The Cotter Dam in December 2005, surrounding country still showing the effects of the 2003 bushfires.
Origin	Scabby Range
Mouth	confluence with Murrumbidgee River
Basin countries	south-east Australia
Length	74 km
Source elevation	1781 m
Mouth elevation	460 m
Avg. discharge	2.21 m³/s immediately downstream Corin Dam
Basin area	482 km²

The Cotter River is a fresh water river in the Australian Capital Territory. It is a tributary of the Murrumbidgee River.

During the 1830s Garret Cotter inhabited the Cotter Valley; the Cotter River received its name by association. Cotter was born in 1802 in County Cork. He had been a ploughman and was transported in 1822 on the Mangles.^[1]^[2] He had a ticket of leave and was working on Lake George. but became involved in a dispute between his employer and his employer's neighbour and was banished to live beyond the limits of location; in this case west of the Murrumbidgee River. After five years of living in the Cotter Valley, he was conditionally pardoned and moved to Michelago.^[3] He was listed as a squatter of Michelago in 1872.^[4]

When the Government surveyor, Charles Scrivener, recommended Canberra as the best site for the national capital, water catchment was a significant consideration. Of the total 910 acres of the Australian Capital Territory, 170 acres were reserved as the catchment area of the Cotter River.^[5] The catchment area was calculated to support a planned population of 100,000.^[6]

There are three reservoirs on the river, the Corin, Bendora and Cotter Dams which supply water to Canberra. Most of the Cotter catchment is in the Namadgi National Park.

Cotter Dam is a concrete gravity dam built in 1912 when the city of Canberra was established. The height of the dam wall was raised in 1951 to increase capacity. The top water level of the dam is 500.69m above sea level. The dam has a capacity of 3,856 million litres; a review in October 2006 using more accurate mapping methods resulted in capacity being re-estimated downwards from the previous estimate of 4,700 million litres. Water was pumped from the dam to Mount Stromlo and from there the water flowed by gravity to fill the city's reservoirs. The dam water quality had deteriorated compared with Bendora and Corin dams and the dam was only used when water is in short supply. However, in December 2004, ActewAGL brought the dam back on line in response to the ongoing drought.^[7]
Bendora Dam, a double curvature concrete arch dam completed in 1961, it has a capacity of 11,540 million litres.
Corin Dam, an earth and rockfill embankment dam completed in 1967, has a capacity of 70,900 million litres. It is the highest dam on the Cotter River. Capacity of the Bendora Dam is controlled by releasing water from the higher Corin Dam into the Cotter River.

As part of a suite of potential options for increasing water storage capacity in the ACT, a plan has been proposed to increase capacity of the Cotter Dam through the construcion of a new 76m high dam wall downstream of the existing Cotter Dam, which would inundate the existing 26m dam wall. This would increase storage capacity of the Cotter Dam from the current 4.7GL to 78GL.

[edit] Recreation

Cotter River picnic area

Although waters of the Cotter Dam itself (along with other dams in the Cotter Catchment) are not able to be utilised for recreation, just past the dam on the Cotter River are a number of popular picnic areas on the river bank. These areas are generally equipped with limited barbecue facilities and tables. There are a number of areas that are suitable for swimming when there is sufficient water flowing in the river. There is also a short term camping site which can accommodate a very limited number of caravans and tents.

The Cotter Road, route 5, begins as a side road off Adelaide Avenue near the suburb of Deakin. The scenic drive stretches 17.6 km from the centre of Canberra past the suburbs of Curtin, Holder and Duffy, in between Stromlo Forest and Narrabundah Hill Pine Plantation, and past Casuarina Sands into the Cotter Avenue river area. "The Cotter" and the adjoining 7.1 km winding Brindabella Road (the beginning of "The Loop") are well known to motorcyclists, many of whom ride there in the evening after work or on weekends. The Cotter Hotel, which stood near the children's swings alongside the river, was burned down in the 2003 bushfires. It was a well known location for motorcyclists to meet on weekend mornings.

[edit] References

^ Mayberry, Peter. Garret Cotter. Irish Convicts to New South Wales 1791-1831. Retrieved on 2006-11-30.
^ Uebel, Lesley (2002). [PJ Mangles 1822: Convicts landed from "Mangles" assigned to at Windsor (Transcribed from Reel 6009; 4/3506 p.432)]. AUS-PT-JACKSON-CONVICTS-L Archives. RootsWeb. Retrieved on 2006-11-30.
^ Chronology of the ACT. Discover our Territory. Canberra & District Historical Society. Retrieved on 2006-11-30.
^ Greville's Post Office Directory - 1872 (letter C) (1872). Retrieved on 2006-11-30.
^ (1954) in Edited by H.L. White: Canberra: A Nation's Capital. Angus and Robertson, Sydney.
^ Wigmore, Lionel (1963). The Long View: Australia's National Capital. Melbourne, Australia: F.W. Cheshire Pty Ltd, page 178.
^ Cotter Dam. Water: Catchment. ActewAGL. Retrieved on 2006-11-29.